Enzyme Nomenclature

Continued from EC 1.6

EC 1.7 and EC 1.8

Sections

EC 1.7 Acting on other nitrogenous compounds as donors
EC 1.7.1 With NAD+ or NADP+ as acceptor
EC 1.7.2 With a cytochrome as acceptor
EC 1.7.3 With oxygen as acceptor
EC 1.7.7 With an iron-sulfur protein as acceptor
EC 1.7.99 With unknown physiological acceptors

EC 1.8 Acting on a sulfur group of donors
EC 1.8.1 With NAD+ or NADP+ as acceptor
EC 1.8.2 With a cytochrome as acceptor
EC 1.8.3 With oxygen as acceptor
EC 1.8.4 With a disulfide as acceptor
EC 1.8.5 With a quinone as acceptor
EC 1.8.6 With nitrogenous group as acceptor
EC 1.8.7 With an iron-sulfur protein as acceptor
EC 1.8.98 With other, known, acceptors
EC 1.8.99 With other acceptors


EC 1.7 ACTING ON OTHER NITROGENOUS COMPOUNDS AS DONORS

EC 1.7.1 With NAD+ or NADP+ as acceptor

Contents

EC 1.7.1.1 nitrate reductase (NADH)
EC 1.7.1.2 nitrate reductase [NAD(P)H]
EC 1.7.1.3 nitrate reductase (NADPH)
EC 1.7.1.4 nitrite reductase [NAD(P)H]
EC 1.7.1.5 hyponitrite reductase
EC 1.7.1.6 azobenzene reductase
EC 1.7.1.7 GMP reductase
EC 1.7.1.8 Deleted entry: withdrawn in the light of further information on the acceptor
EC 1.7.1.9 nitroquinoline-N-oxide reductase
EC 1.7.1.10 hydroxylamine reductase (NADH)
EC 1.7.1.11 4-(dimethylamino)phenylazoxybenzene reductase
EC 1.7.1.12 N-hydroxy-2-acetamidofluorene reductase
EC 1.7.1.13 preQ1 reductase
EC 1.7.1.14 nitric oxide reductase [NAD(P)+, nitrous oxide-forming]
EC 1.7.1.15 nitrite reductase (NADH)
EC 1.7.1.16 nitrobenzene nitroreductase
EC 1.7.1.17 FMN-dependent NADH-azoreductase


EC 1.7.1.1

Accepted name: nitrate reductase (NADH)

Reaction: nitrite + NAD+ + H2O = nitrate + NADH + H+

Other name(s): assimilatory nitrate reductase (ambiguous); NADH-nitrate reductase; NADH-dependent nitrate reductase; assimilatory NADH: nitrate reductase; nitrate reductase (NADH2); NADH2:nitrate oxidoreductase

Systematic name: nitrite:NAD+ oxidoreductase

Comments: An iron-sulfur molybdenum flavoprotein.

Links to other databases: BRENDA, EAWAG-BBD, EXPASY, KEGG, Metacyc, PDB, CAS registry number: 9013-03-0

References:

1. Fewson, C.A. and Nicholas, D.J.D. Nitrate reductase from Pseudomonas aeruginosa. Biochim. Biophys. Acta 49 (1961) 335-349.

2. Nason, A. Nitrate reductases. In: Boyer, P.D., Lardy, H. and Myrbäck, K. (Eds.), The Enzymes, 2nd ed., vol. 7, Academic Press, New York, 1963, pp. 587-607.

3. Nicholas, D.J.D. and Nason, A. Diphosphopyridine nucleotide-nitrate reductase from Escherichia coli. J. Bacteriol. 69 (1955) 580-583.

4. Spencer, D. A reduced diphosphopyridine-specific nitrate reductase from germinating wheat. Aust. J. Biol. Sci. 12 (1959) 181-189.

5. Berks, B.C., Ferguson, S.J., Moir, J.W. and Richardson, D.J. Enzymes and associated electron transport systems that catalyse the respiratory reduction of nitrogen oxides and oxyanions. Biochim. Biophys. Acta 1232 (1995) 97-173. [PMID: 8534676]

[EC 1.7.1.1 created 1961 as EC 1.6.6.1, transferred 2002 to EC 1.7.1.1]

EC 1.7.1.2

Accepted name: nitrate reductase [NAD(P)H]

Reaction: nitrite + NAD(P)+ + H2O = nitrate + NAD(P)H + H+

Other name(s): assimilatory nitrate reductase (ambiguous); assimilatory NAD(P)H-nitrate reductase; NAD(P)H bispecific nitrate reductase; nitrate reductase (reduced nicotinamide adenine dinucleotide (phosphate)); nitrate reductase NAD(P)H; NAD(P)H-nitrate reductase; nitrate reductase [NAD(P)H2]; NAD(P)H2:nitrate oxidoreductase

Systematic name: nitrite:NAD(P)+ oxidoreductase

Comments: An iron-sulfur molybdenum flavoprotein.

Links to other databases: BRENDA, EXPASY, KEGG, Metacyc, PDB, CAS registry number: 9029-27-0

References:

1. Nason, A. Nitrate reductases. In: Boyer, P.D., Lardy, H. and Myrbäck, K. (Eds.), The Enzymes, 2nd ed., vol. 7, Academic Press, New York, 1963, pp. 587-607.

2. Paneque, A., Del Campo, F.F., Ramirez, J.M. and Losada, M. Flavin nucleotide nitrate reductase from spinach. Biochim. Biophys. Acta 109 (1965) 79-85. [PMID: 5864033]

3. Campbell, W.H. Structure and function of eukaryotic NAD(P)H:nitrate reductase. Cell. Mol. Life Sci. 58 (2001) 194-204. [PMID: 11289301]

4. Berks, B.C., Ferguson, S.J., Moir, J.W. and Richardson, D.J. Enzymes and associated electron transport systems that catalyse the respiratory reduction of nitrogen oxides and oxyanions. Biochim. Biophys. Acta 1232 (1995) 97-173. [PMID: 8534676]

[EC 1.7.1.2 created 1961 as EC 1.6.6.2, transferred 2002 to EC 1.7.1.2]

EC 1.7.1.3

Accepted name: nitrate reductase (NADPH)

Reaction: nitrite + NADP+ + H2O = nitrate + NADPH + H+

Other name(s): assimilatory nitrate reductase (ambiguous); assimilatory reduced nicotinamide adenine dinucleotide phosphate-nitrate reductase; NADPH-nitrate reductase; assimilatory NADPH-nitrate reductase; triphosphopyridine nucleotide-nitrate reductase; NADPH:nitrate reductase; nitrate reductase (NADPH2); NADPH2:nitrate oxidoreductase

Systematic name: nitrite:NADP+ oxidoreductase

Comments: An iron-sulfur molybdenum flavoprotein.

Links to other databases: BRENDA, EXPASY, KEGG, Metacyc, PDB, CAS registry number: 9029-28-1

References:

1. Nason, A. Nitrate reductases. In: Boyer, P.D., Lardy, H. and Myrbäck, K. (Eds.), The Enzymes, 2nd ed., vol. 7, Academic Press, New York, 1963, pp. 587-607.

2. Nason, A. and Evans, H.J. Triphosphopyridine nucleotide-nitrate reductase in Neurospora. J. Biol. Chem. 202 (1953) 655-673.

3. Nicholas, D.J.D. and Nason, A. Molybdenum and nitrate reductase. II. Molybdenum as a constituent of nitrate reductase. J. Biol. Chem. 207 (1954) 353-360.

4. Taniguchi, H., Mitsui, H., Nakamura, K. and Egami, F. Ann. Acad. Sci. Fenn. Ser. A II 60 (1955) 200.

5. Berks, B.C., Ferguson, S.J., Moir, J.W. and Richardson, D.J. Enzymes and associated electron transport systems that catalyse the respiratory reduction of nitrogen oxides and oxyanions. Biochim. Biophys. Acta 1232 (1995) 97-173. [PMID: 8534676]

[EC 1.7.1.3 created 1961 as EC 1.6.6.3, transferred 2002 to EC 1.7.1.3]

EC 1.7.1.4

Accepted name: nitrite reductase [NAD(P)H]

Reaction: NH3 + 3 NAD(P)+ + 2 H2O = nitrite + 3 NAD(P)H + 5 H+

Other name(s): nitrite reductase (reduced nicotinamide adenine dinucleotide (phosphate)); assimilatory nitrite reductase (ambiguous); nitrite reductase [NAD(P)H2]; NAD(P)H2:nitrite oxidoreductase; nit-6 (gene name)

Systematic name: ammonia:NAD(P)+ oxidoreductase

Comments: An iron-sulfur flavoprotein (FAD) containing siroheme. The enzymes from the fungi Neurospora crassa [1], Emericella nidulans [2] and Candida nitratophila [3] can use either NADPH or NADH as electron donor. cf. EC 1.7.1.15, nitrite reductase (NADH).

Links to other databases: BRENDA, EXPASY, KEGG, Metacyc, PDB, CAS registry number: 9029-29-2

References:

1. Nicholas, D.J.D., Medina, A. and Jones, O.T.G. A nitrite reductase from Neurospora crassa. Biochim. Biophys. Acta 37 (1960) 468-476.

2. Pateman, J.A., Rever, B.M. and Cove, D.J. Genetic and biochemical studies of nitrate reduction in Aspergillus nidulans. Biochem. J. 104 (1967) 103-111. [PMID: 4382427]

3. Rivas, J., Guerrero, M. G., Paneque, A. and Losada, M. Characterization of the nitrate-reducing system of the yeast Torulopsis nitratophila. Plant Sci. Lett. 1 (1973) 105-113.

4. Lafferty, M.A. and Garrett, R.H. Purification and properties of the Neurospora crassa assimilatory nitrite reductase. J. Biol. Chem. 249 (1974) 7555-7567. [PMID: 4154942]

5. Vega, J.M. and Garrett, R.H. Siroheme: a prosthetic group of the Neurospora crassa assimilatory nitrite reductase. J. Biol. Chem. 250 (1975) 7980-7989. [PMID: 126995]

6. Greenbaum, P., Prodouz, K.N. and Garrett, R.H. Preparation and some properties of homogeneous Neurospora crassa assimilatory NADPH-nitrite reductase. Biochim. Biophys. Acta 526 (1978) 52-64. [PMID: 150863]

7. Prodouz, K.N. and Garrett, R.H. Neurospora crassa NAD(P)H-nitrite reductase. Studies on its composition and structure. J. Biol. Chem. 256 (1981) 9711-9717. [PMID: 6457037]

8. Exley, G.E., Colandene, J.D. and Garrett, R.H. Molecular cloning, characterization, and nucleotide sequence of nit-6, the structural gene for nitrite reductase in Neurospora crassa. J. Bacteriol. 175 (1993) 2379-2392. [PMID: 8096840]

9. Colandene, J.D. and Garrett, R.H. Functional dissection and site-directed mutagenesis of the structural gene for NAD(P)H-nitrite reductase in Neurospora crassa. J. Biol. Chem. 271 (1996) 24096-24104. [PMID: 8798648]

[EC 1.7.1.4 created 1961 as EC 1.6.6.4, transferred 2002 to EC 1.7.1.4, modified 2013]

EC 1.7.1.5

Accepted name: hyponitrite reductase

Reaction: 2 hydroxylamine + 2 NAD+ = hyponitrous acid + 2 NADH + 2 H+

Glossary: hypnitrous acid = HO-N=N-OH

Other name(s): NADH2:hyponitrite oxidoreductase

Systematic name: hydroxylamine:NAD+ oxidoreductase

Comments: A metalloprotein.

Links to other databases: BRENDA, EXPASY, KEGG, Metacyc, CAS registry number: 9029-30-5

References:

1. Medina, A. and Nicholas, D.J.D. Hyponitrite reductase in Neurospora. Nature (Lond.) 179 (1957) 533-534.

[EC 1.7.1.5 created 1961 as EC 1.6.6.6, transferred 2002 to EC 1.7.1.5]

EC 1.7.1.6

Accepted name: azobenzene reductase

Reaction: N,N-dimethyl-1,4-phenylenediamine + aniline + NADP+ = 4-(dimethylamino)azobenzene + NADPH + H+

Glossary: 4-(dimethylamino)azobenzene = Methyl Yellow

Other name(s): new coccine (NC)-reductase; NC-reductase; azo-dye reductase; orange II azoreductase; NAD(P)H:1-(4'-sulfophenylazo)-2-naphthol oxidoreductase; orange I azoreductase; azo reductase; azoreductase; nicotinamide adenine dinucleotide (phosphate) azoreductase; NADPH2-dependent azoreductase; dimethylaminobenzene reductase; p-dimethylaminoazobenzene azoreductase; dibromopropylaminophenylazobenzoic azoreductase; N,N-dimethyl-4-phenylazoaniline azoreductase; p-aminoazobenzene reductase; methyl red azoreductase; NADPH2:4-(dimethylamino)azobenzene oxidoreductase

Systematic name: N,N-dimethyl-1,4-phenylenediamine, aniline:NADP+ oxidoreductase

Comments: The reaction occurs in the reverse direction to that shown above. Other azo dyes, such as Methyl Red, Rocceline, Solar Orange and Sumifix Black B can also be reduced [2].

Links to other databases: BRENDA, EAWAG-BBD, EXPASY, KEGG, Metacyc, CAS registry number: 9029-31-6

References:

1. Mueller, G.C. and Miller, J.A. The reductive cleavage of 4-dimethylaminoazobenzene by rat liver: the intracellular distribution of the enzyme system and its requirements for triphosphopyridine nucleotide. J. Biol. Chem. 180 (1949) 1125-1136.

2. Suzuki, Y., Yoda, T., Ruhul, A. and Sugiura, W. Molecular cloning and characterization of the gene coding for azoreductase from Bacillus sp. OY1-2 isolated from soil. J. Biol. Chem. 276 (2001) 9059-9065. [PMID: 11134015]

[EC 1.7.1.6 created 1961 as EC 1.6.6.7, transferred 2002 to EC 1.7.1.6]

EC 1.7.1.7

Accepted name: GMP reductase

Reaction: IMP + NH3 + NADP+ = GMP + NADPH + H+

Glossary: IMP = inosine 5'-phosphate
GMP = guanosine 5'-phosphate

Other name(s): guanosine 5'-monophosphate reductase; NADPH:GMP oxidoreductase (deaminating); guanosine monophosphate reductase; guanylate reductase; NADPH2:guanosine-5'-phosphate oxidoreductase (deaminating); guanosine 5'-phosphate reductase

Systematic name: inosine-5'-phosphate:NADP+ oxidoreductase (aminating)

Links to other databases: BRENDA, EXPASY, KEGG, Metacyc, PDB, CAS registry number: 9029-32-7

References:

1. MacKenzie, J.J. and Sorensen, L.B. Guanosine 5'-phosphate reductase of human erythrocytes. Biochim. Biophys. Acta 327 (1973) 282-294. [PMID: 4149840]

2. Mager, J. and Magasanik, B. Guanosine 5'-phosphate reductase and its role in the interconversion of purine nucleotides. J. Biol. Chem. 235 (1960) 1474-1478.

[EC 1.7.1.7 created 1965 as EC 1.6.6.8, transferred 2002 to EC 1.7.1.7]

[EC 1.7.1.8 Deleted entry: withdrawn in the light of further information on the acceptor (EC 1.7.1.8 created 2002, deleted 2002)]

EC 1.7.1.9

Accepted name: nitroquinoline-N-oxide reductase

Reaction: 4-(hydroxyamino)quinoline N-oxide + 2 NAD(P)+ + H2O = 4-nitroquinoline N-oxide + 2 NAD(P)H + 2 H+

Other name(s): 4-nitroquinoline 1-oxide reductase; 4NQO reductase; NAD(P)H2:4-nitroquinoline-N-oxide oxidoreductase

Systematic name: 4-(hydroxyamino)quinoline N-oxide:NADP+ oxidoreductase

Links to other databases: BRENDA, EXPASY, KEGG, Metacyc, CAS registry number: 37256-35-2

References:

1. Toriyama, N. [Metabolism of quinoline derivatives. On the reducing enzyme of 4-nitroquinoline-N-oxide] Nichidai Igaku Zasshi 24 (1965) 423-432. (in Japanese)

2. Stanley, J.S., York, J.L. and Benson AM. Nitroreductases and glutathione transferases that act on 4-nitroquinoline 1-oxide and their differential induction by butylated hydroxyanisole in mice. Cancer Res. 52 (1992) 58-63. [PMID: 1370076]

[EC 1.7.1.9 created 1972 as EC 1.6.6.10, transferred 2002 to EC 1.7.1.9]

EC 1.7.1.10

Accepted name: hydroxylamine reductase (NADH)

Reaction: NH3 + NAD+ + H2O = hydroxylamine + NADH + H+

Other name(s): hydroxylamine reductase; ammonium dehydrogenase; NADH-hydroxylamine reductase; N-hydroxy amine reductase; hydroxylamine reductase (NADH2); NADH2:hydroxylamine oxidoreductase

Systematic name: ammonium:NAD+ oxidoreductase

Comments: Also acts on some hydroxamates.

Links to other databases: BRENDA, EXPASY, KEGG, Metacyc, CAS registry number: 9032-06-8

References:

1. Bernheim, M.L.C. The hydroxylamine reductase of mitochondria. Arch. Biochem. Biophys. 134 (1969) 408-413. [PMID: 4311180]

2. Bernheim, M.L.C. and Hochstein, P. Reduction of hydroxylamine by rat liver mitochondria. Arch. Biochem. Biophys. 124 (1968) 436-442. [PMID: 4298499]

3. Wang, R. and Nicholas, D.J.D. Some properties of nitrite and hydroxylamine reductases from Derxia gummosa. Phytochemistry 25 (1986) 2463-2469.

[EC 1.7.1.10 created 1972 as EC 1.6.6.11, transferred 2002 to EC 1.7.1.10]

EC 1.7.1.11

Accepted name: 4-(dimethylamino)phenylazoxybenzene reductase

Reaction: 4-(dimethylamino)phenylazobenzene + NADP+ + H2O = 4-(dimethylamino)phenylazoxybenzene + NADPH + H+

Other name(s): N,N-dimethyl-p-aminoazobenzene oxide reductase; dimethylaminoazobenzene N-oxide reductase; NADPH-dependent DMAB N-oxide reductase; NADPH2:4-(dimethylamino)phenylazoxybenzene oxidoreductase

Systematic name: 4-(dimethylamino)phenylazobenzene:NADP+ oxidoreductase

Links to other databases: BRENDA, EXPASY, KEGG, Metacyc, CAS registry number: 103843-39-6

References:

1. Lashmet Johnson, P.R. and Ziegler, D.M. Properties of an N,N-dimethyl-p-aminoazobenzene oxide reductase purified from rat liver cytosol. J. Biochem. Toxicol. 1 (1986) 15-27. [PMID: 3152268]

[EC 1.7.1.11 created 1989 as EC 1.6.6.12, transferred 2002 to EC 1.7.1.11]

EC 1.7.1.12

Accepted name: N-hydroxy-2-acetamidofluorene reductase

Reaction: 2-acetamidofluorene + NAD(P)+ + H2O = N-hydroxy-2-acetamidofluorene + NAD(P)H + H+

Other name(s): N-hydroxy-2-acetylaminofluorene reductase; NAD(P)H2:N-hydroxy-2-acetamidofluorene N-oxidoreductase

Systematic name: 2-acetamidofluorene:NAD(P)+ oxidoreductase

Comments: Also acts, more slowly, on N-hydroxy-4-acetamidobiphenyl.

Links to other databases: BRENDA, EXPASY, KEGG, Metacyc, CAS registry number: 99890-08-1

References:

1. Gutmann, H.R. and Erickson, R.R. The conversion of the carcinogen N-hydroxy-2-fluorenylacetamide to o-amidophenols by rat liver in vitro. An inducible enzymatic reaction. J. Biol. Chem. 244 (1969) 1729-1740. [PMID: 5780838]

2. Kitamura, S. and Tatsumi, K. Purification of N-hydroxy-2-acetylaminofluorene reductase from rabbit liver cytosol. Biochem. Biophys. Res. Commun. 133 (1985) 67-74. [PMID: 4074379]

[EC 1.7.1.12 created 1989 as EC 1.6.6.13, transferred 2002 to EC 1.7.1.12]

EC 1.7.1.13

Accepted name: preQ1 synthase

Reaction: 7-aminomethyl-7-carbaguanine + 2 NADP+ = 7-cyano-7-carbaguanine + 2 NADPH

Glossary: 7-aminomethyl-7-carbaguanine = preQ1 = 7-aminomethyl-7-deazaguanine
7-cyano-7-carbaguanine = preQ0 = 7-cyano-7-deazaguanine

Other name(s): YkvM; QueF; preQ0 reductase; preQ0 oxidoreductase; 7-cyano-7-deazaguanine reductase

Systematic name: 7-aminomethyl-7-carbaguanine:NADP+ oxidoreductase

Comments: The reaction occurs in the reverse direction. This enzyme catalyses one of the later steps in the synthesis of queosine (Q-tRNA), following on from the action of EC 2.4.2.29, tRNA-guanosine34 transglycosylase. Queuosine is found in the wobble position of tRNAGUN in Eukarya and Bacteria [2] and is thought to be involved in translational modulation. The enzyme is not a GTP cyclohydrolase, as was thought previously based on sequence-homology studies.

Links to other databases: BRENDA, EXPASY, KEGG, Metacyc, PDB, CAS registry number: 1256460-80-6

References:

1. Van Lanen, S.G., Reader, J.S., Swairjo, M.A., de Crécy-Lagard, V., Lee, B. and Iwata-Reuyl, D. From cyclohydrolase to oxidoreductase: discovery of nitrile reductase activity in a common fold. Proc. Natl. Acad. Sci. USA 102 (2005) 4264-4269. [PMID: 15767583]

2. Yokoyama, S., Miyazawa, T., Iitaka, Y., Yamaizumi, Z., Kasai, H. and Nishimura, S. Three-dimensional structure of hyper-modified nucleoside Q located in the wobbling position of tRNA. Nature 282 (1979) 107-109. [PMID: 388227]

3. Kuchino, Y., Kasai, H., Nihei, K. and Nishimura, S. Biosynthesis of the modified nucleoside Q in transfer RNA. Nucleic Acids Res. 3 (1976) 393-398. [PMID: 1257053]

4. Okada, N., Noguchi, S., Nishimura, S., Ohgi, T., Goto, T., Crain, P.F. and McCloskey, J.A. Structure determination of a nucleoside Q precursor isolated from E. coli tRNA: 7-(aminomethyl)-7-deazaguanosine. Nucleic Acids Res. 5 (1978) 2289-2296. [PMID: 353740]

5. Noguchi, S., Yamaizumi, Z., Ohgi, T., Goto, T., Nishimura, Y., Hirota, Y. and Nishimura, S. Isolation of Q nucleoside precursor present in tRNA of an E. coli mutant and its characterization as 7-(cyano)-7-deazaguanosine. Nucleic Acids Res. 5 (1978) 4215-4223. [PMID: 364423]

6. Swairjo, M.A., Reddy, R.R., Lee, B., Van Lanen, S.G., Brown, S., de Cr̩cy-Lagard, V., Iwata-Reuyl, D. and Schimmel, P. Crystallization and preliminary X-ray characterization of the nitrile reductase QueF: a queuosine-biosynthesis enzyme. Acta Crystallogr. F Struct. Biol. Crystal. Co 61 (2005) 945-948.

[EC 1.7.1.13 created 2006]

EC 1.7.1.14

Accepted name: nitric oxide reductase [NAD(P)+, nitrous oxide-forming]

Reaction: N2O + NAD(P)+ + H2O = 2 NO + NAD(P)H + H+

Other name(s): fungal nitric oxide reductase; cytochrome P450nor; NOR (ambiguous)

Systematic name: nitrous oxide:NAD(P) oxidoreductase

Comments: A heme-thiolate protein (P450). The enzyme from Fusarium oxysporum utilizes only NADH, but the isozyme from Trichosporon cutaneum utilizes both NADH and NADPH. The electron transfer from NAD(P)H to heme occurs directly, not requiring flavin or other redox cofactors.

Links to other databases: BRENDA, EXPASY, KEGG, Metacyc, PDB, CAS registry number:

References:

1. Shoun, H. and Tanimoto, T. Denitrification by the fungus Fusarium oxysporum and involvement of cytochrome P-450 in the respiratory nitrite reduction. J. Biol. Chem. 266 (1991) 11078-11082. [PMID: 2040619]

2. Shiro, Y., Fujii, M., Iizuka, T., Adachi, S., Tsukamoto, K., Nakahara, K. and Shoun, H. Spectroscopic and kinetic studies on reaction of cytochrome P450nor with nitric oxide. Implication for its nitric oxide reduction mechanism. J. Biol. Chem. 270 (1995) 1617-1623. [PMID: 7829493]

3. Zhang, L., Kudo, T., Takaya, N. and Shoun, H. The B' helix determines cytochrome P450nor specificity for the electron donors NADH and NADPH. J. Biol. Chem. 277 (2002) 33842-33847. [PMID: 12105197]

4. Oshima, R., Fushinobu, S., Su, F., Zhang, L., Takaya, N. and Shoun, H. Structural evidence for direct hydride transfer from NADH to cytochrome P450nor. J. Mol. Biol. 342 (2004) 207-217. [PMID: 15313618]

[EC 1.7.1.14 created 2011]

EC 1.7.1.15

Accepted name: nitrite reductase (NADH)

Reaction: NH3 + 3 NAD+ + 2 H2O = nitrite + 3 NADH + 5 H+

Other name(s): nitrite reductase (reduced nicotinamide adenine dinucleotide); NADH-nitrite oxidoreductase; assimilatory nitrite reductase (ambiguous); nirB (gene name); nirD (gene name)

Systematic name: ammonia:NAD+ oxidoreductase

Comments: An iron-sulfur flavoprotein (FAD) containing siroheme. This prokaryotic enzyme is specific for NADH. In addition to catalysing the 6-electron reduction of nitrite to ammonia, the enzyme from Escherichia coli can also catalyse the 2-electron reduction of hydroxylamine to ammonia. cf. EC 1.7.1.4, nitrite reductase [NAD(P)H].

Links to other databases: BRENDA, EXPASY, KEGG, Metacyc, CAS registry number:

References:

1. Vega, J.M., Guerrero, M.G., Leadbetter, E. and Losada, M. Reduced nicotinamide-adenine dinucleotide-nitrite reductase from Azotobacter chroococcum. Biochem. J. 133 (1973) 701-708. [PMID: 4147887]

2. Jackson, R.H., Cornish-Bowden, A. and Cole, J.A. Prosthetic groups of the NADH-dependent nitrite reductase from Escherichia coli K12. Biochem. J. 193 (1981) 861-867. [PMID: 7030314]

3. Cammack, R., Jackson, R.H., Cornish-Bowden, A. and Cole, J.A. Electron-spin-resonance studies of the NADH-dependent nitrite reductase from Escherichia coli K12. Biochem. J. 207 (1982) 333-339. [PMID: 6297458]

4. Harborne, N.R., Griffiths, L., Busby, S.J. and Cole, J.A. Transcriptional control, translation and function of the products of the five open reading frames of the Escherichia coli nir operon. Mol. Microbiol. 6 (1992) 2805-2813. [PMID: 1435259]

[EC 1.7.1.15 created 2013]

EC 1.7.1.16

Accepted name: nitrobenzene nitroreductase

Reaction: N-phenylhydroxylamine + 2 NADP+ + H2O = nitrobenzene + 2 NADPH + 2 H+ (overall reaction)
(1a) N-phenylhydroxylamine + NADP+ = nitrosobenzene + NADPH + H+
(1b) nitrosobenzene + NADP+ + H2O = nitrobenzene + NADPH + H+

Other name(s): cnbA (gene name)

Systematic name: N-phenylhydroxylamine:NADP+ oxidoreductase

Comments: Contains FMN. The enzyme, characterized from Pseudomonas species, catalyses two successive reductions of nitrobenzene, via a nitrosobenzene intermediate. It is also active on 1-chloro-4-nitrobenzene.

Links to other databases: BRENDA, EXPASY, KEGG, Metacyc, CAS registry number:

References:

1. Somerville, C.C., Nishino, S.F. and Spain, J.C. Purification and characterization of nitrobenzene nitroreductase from Pseudomonas pseudoalcaligenes JS45. J. Bacteriol. 177 (1995) 3837-3842. [PMID: 7601851]

2. Wu, J.F., Jiang, C.Y., Wang, B.J., Ma, Y.F., Liu, Z.P. and Liu, S.J. Novel partial reductive pathway for 4-chloronitrobenzene and nitrobenzene degradation in Comamonas sp. strain CNB-1. Appl. Environ. Microbiol. 72 (2006) 1759-1765. [PMID: 16517619]

[EC 1.7.1.16 created 2017]

EC 1.7.1.17

Accepted name: FMN-dependent NADH-azoreductase

Reaction: anthranilate + N,N-dimethyl-1,4-phenylenediamine + 2 NAD+ = 2-(4-dimethylaminophenyl)diazenylbenzoate + 2 NADH + 2 H+

Glossary: 2-(4-dimethylaminophenyl)diazenylbenzoate = methyl red

Other name(s): azoR (gene name); NADH-azoreductase

Systematic name: N,N-dimethyl-1,4-phenylenediamine, anthranilate:NAD+ oxidoreductase

Comments: Requires FMN. The enzyme catalyses the reductive cleavage of an azo bond in aromatic azo compounds to form the corresponding amines. Does not accept NADPH. cf. EC 1.7.1.6, azobenzene reductase.

Links to other databases: BRENDA, EXPASY, KEGG, MetaCyc, PDB, CAS registry number:

References:

1. Nakanishi, M., Yatome, C., Ishida, N. and Kitade, Y. Putative ACP phosphodiesterase gene (acpD) encodes an azoreductase. J. Biol. Chem. 276 (2001) 46394-46399. [PMID: 11583992]

2. Ito, K., Nakanishi, M., Lee, W.C., Sasaki, H., Zenno, S., Saigo, K., Kitade, Y. and Tanokura, M. Crystallization and preliminary X-ray analysis of AzoR (azoreductase) from Escherichia coli. Acta Crystallogr. Sect. F Struct. Biol. Cryst. Commun. 61 (2005) 399-402. [PMID: 16511052]

3. Ito, K., Nakanishi, M., Lee, W.C., Zhi, Y., Sasaki, H., Zenno, S., Saigo, K., Kitade, Y. and Tanokura, M. Expansion of substrate specificity and catalytic mechanism of azoreductase by X-ray crystallography and site-directed mutagenesis. J. Biol. Chem. 283 (2008) 13889-13896. [PMID: 18337254]

4. Mercier, C., Chalansonnet, V., Orenga, S. and Gilbert, C. Characteristics of major Escherichia coli reductases involved in aerobic nitro and azo reduction. J. Appl. Microbiol. 115 (2013) 1012-1022. [PMID: 23795903]

[EC 1.7.1.17 created 2018]


EC 1.7.2 With a cytochrome as acceptor

Contents

EC 1.7.2.1 nitrite reductase (NO-forming)
EC 1.7.2.2 nitrite reductase (cytochrome; ammonia-forming)
EC 1.7.2.3 trimethylamine-N-oxide reductase
EC 1.7.2.4 nitrous-oxide reductase
EC 1.7.2.5 nitric oxide reductase (cytochrome c)
EC 1.7.2.6 hydroxylamine dehydrogenase
EC 1.7.2.7 hydrazine synthase
EC 1.7.2.8 hydrazine dehydrogenase
EC 1.7.2.9 hydroxylamine oxidase

EC 1.7.2.1

Accepted name: nitrite reductase (NO-forming)

Reaction: nitric oxide + H2O + ferricytochrome c = nitrite + ferrocytochrome c + 2 H+

Glossary: nitric oxide = NO = nitrogen(II) oxide

Other name(s): cd-cytochrome nitrite reductase; [nitrite reductase (cytochrome)] [misleading, see comments.]; cytochrome c-551:O2, NO2+ oxidoreductase; cytochrome cd; cytochrome cd1; hydroxylamine (acceptor) reductase; methyl viologen-nitrite reductase; nitrite reductase (cytochrome; NO-forming)

Systematic name: nitric-oxide:ferricytochrome-c oxidoreductase

Comments: The reaction is catalysed by two types of enzymes, found in the perimplasm of denitrifying bacteria. One type comprises proteins containing multiple copper centres, the other a heme protein, cytochrome cd1. Acceptors include c-type cytochromes such as cytochrome c-550 or cytochrome c-551 from Paracoccus denitrificans or Pseudomonas aeruginosa, and small blue copper proteins such as azurin and pseudoazurin. Cytochrome cd1 also has oxidase and hydroxylamine reductase activities. May also catalyse the reaction of hydroxylamine reductase (EC 1.7.99.1) since this is a well-known activity of cytochrome cd1.

Links to other databases: BRENDA, EAWAG-BBD, EXPASY, KEGG, Metacyc, PDB, CAS registry number: 9080-03-9

References:

1. Miyata, M. and Mori, T. Studies on denitrification. X. The "denitrifying enzyme" as a nitrite reductase and the electron donating system for denitrification. J. Biochem. (Tokyo) 66 (1969) 463-471. [PMID: 5354021]

2. Chung, C.W. and Najjar, V.A. Cofactor requirements for enzymatic denitrification. I. Nitrite reductase. J. Biol. Chem. 218 (1956) 617-625.

3. Walker, G.C. and Nicholas, D.J.D. Nitrite reductase from Pseudomonas aeruginosa. Biochim. Biophys. Acta 49 (1961) 350-360.

4. Singh, J. Cytochrome oxidase from Pseudomonas aeruginosa. III. Reduction of hydroxylamine. Biochim. Biophys. Acta 333 (1974) 28-36.

5. Michalski, W.P. and Nicholas, D.J.D. Molecular characterization of a copper-containing nitrite reductase from Rhodopseudomonas sphaeriodes forma sp. Denitrificans. Biochim. Biophys. Acta 828 (1985) 130-137.

6. Godden, J.W., Turley, S., Teller, D.C., Adman, E.T., Liu, M.Y., Payne, W.J. and Legall, J. The 2.3 angstrom X-ray structure of nitrite reductase from Achromobacter cycloclastes. Science 253 (1991) 438-442. [PMID: 1862344]

7. Williams, P.A., Fulop, V., Leung, Y.C., Chan, C., Moir, J.W.B., Howlett, G., Ferguson, S.J., Radford, S.E. and Hajdu, J. Pseudospecific docking surfaces on electron transfer proteins as illustrated by pseudoazurin, cytochrome c-550 and cytochrome cd1 nitrite reductase. Nat. Struct. Biol. 2 (1995) 975-982. [PMID: 7583671]

8. Hole, U.H., Vollack, K.U., Zumft, W.G., Eisenmann, E., Siddiqui, R.A., Friedrich, B. and Kroneck, P.M.H. Characterization of the membranous denitrification enzymes nitrite reductase (cytochrome cd1) and copper-containing nitrous oxide reductase from Thiobacillus denitrificans. Arch. Microbiol. 165 (1996) 55-61. [PMID: 8639023]

9. Zumft, W.G. Cell biology and molecular basis of denitrification. Microbiol. Mol. Biol. Rev. 61 (1997) 533-616. [PMID: 9409151]

10. Ferguson, S.J. Nitrogen cycle enzymology. Curr. Opin. Chem. Biol. 2 (1998) 182-193. [PMID: 9667932]

11. Vijgenboom, E., Busch, J.E. and Canters, G.W. In vitro studies disprove the obligatory role of azurin in denitrification in Pseudomonas aeruginosa and show that azu expression is under the control of RpoS and ANR. Microbiology 143 (1997) 2853-2863. [PMID: 9308169]

[EC 1.7.2.1 created 1961, modified 1976, modified 2001, modified 2002 (EC 1.7.99.3 created 1961 as EC 1.6.6.5, transferred 1964 to EC 1.7.99.3, modified 1976, incorporated 2002; EC 1.9.3.2 created 1965, incorporated 2002)]

EC 1.7.2.2

Accepted name: nitrite reductase (cytochrome; ammonia-forming)

Reaction: NH3 + 2 H2O + 6 ferricytochrome c = nitrite + 6 ferrocytochrome c + 7 H+

Other names: cytochrome c nitrite reductase; multiheme nitrite reductase

Systematic name: ammonia:ferricytochrome-c oxidoreductase

Comments: Found as a multiheme cytochrome in many bacteria. The enzyme from Escherichia coli contains five hemes c and requires Ca2+. It also reduces nitric oxide and hydroxylamine to ammonia, and sulfite to sulfide.

Links to other databases: BRENDA, EAWAG-BBD, EXPASY, KEGG, Metacyc, PDB, CAS registry number:

References:

1. Einsle, O., Messerschmidt, A., Stach, P. Bourenkov, G.P., Bartunik, H.D., Huber, R. and Kroneck, P.M.H. Structure of cytochrome c nitrite reductase. Nature 400 (1999) 476-480. [PMID: 10440380]

[EC 1.7.2.2 created 2001]

EC 1.7.2.3

Accepted name: trimethylamine-N-oxide reductase

Reaction: trimethylamine + 2 (ferricytochrome c)-subunit + H2O = trimethylamine N-oxide + 2 (ferrocytochrome c)-subunit + 2 H+

For diagram of reaction click here

Other name(s): TMAO reductase; TOR; torA (gene name); torZ (gene name); bisZ (gene name); trimethylamine-N-oxide reductase (cytochrome c)

Systematic name: trimethylamine:cytochrome c oxidoreductase

Comments: Contains bis(molybdopterin guanine dinucleotide)molybdenum cofactor. The reductant is a membrane-bound multiheme cytochrome c. Also reduces dimethyl sulfoxide to dimethyl sulfide.

Links to other databases: BRENDA, EXPASY, ExplorEnz, KEGG, MetaCyc, PDB, CAS registry number: 37256-34-1

References:

1. Arata, H., Shimizu, M. and Takamiya, K. Purification and properties of trimethylamine N-oxide reductase from aerobic photosynthetic bacterium Roseobacter denitrificans. J. Biochem. (Tokyo) 112 (1992) 470-475. [PMID: 1337081]

2. Knablein, J., Dobbek, H., Ehlert, S. and Schneider, F. Isolation, cloning, sequence analysis and X-ray structure of dimethyl sulfoxide trimethylamine N-oxide reductase from Rhodobacter capsulatus. Biol. Chem. 378 (1997) 293-302. [PMID: 9165084]

3. Czjzek, M., Dos Santos, J.P., Pommier, J., Giordano, G., Méjean, V. and Haser, R. Crystal structure of oxidized trimethylamine N-oxide reductase from Shewanella massilia at 2.5 Å resolution. J. Mol. Biol. 284 (1998) 435-447. [PMID: 9813128]

4. Gon, S., Giudici-Orticoni, M.T., Mejean, V. and Iobbi-Nivol, C. Electron transfer and binding of the c-type cytochrome TorC to the trimethylamine N-oxide reductase in Escherichia coli. J. Biol. Chem. 276 (2001) 11545-11551. [PMID: 11056172]

5. Zhang, L., Nelson, K.J., Rajagopalan, K.V. and George, G.N. Structure of the molybdenum site of Escherichia coli trimethylamine N-oxide reductase. Inorg. Chem. 47 (2008) 1074-1078. [PMID: 18163615]

6. Yin, Q.J., Zhang, W.J., Qi, X.Q., Zhang, S.D., Jiang, T., Li, X.G., Chen, Y., Santini, C.L., Zhou, H., Chou, I.M. and Wu, L.F. High hydrostatic pressure inducible trimethylamine N-oxide reductase improves the pressure tolerance of piezosensitive bacteria Vibrio fluvialis. Front Microbiol 8 (2017) 2646. [PMID: 29375513]

[EC 1.7.2.3 created 2002, modified 2018]

EC 1.7.2.4

Accepted name: nitrous-oxide reductase

Reaction: nitrogen + H2O + 2 cytochrome c = nitrous oxide + 2 reduced cytochrome c

Other name(s): nitrous oxide reductase; N2O reductase; nitrogen:(acceptor) oxidoreductase (N2O-forming)

Systematic name: nitrogen:cytochrome c oxidoreductase (N2O-forming)

Comments: The reaction is observed only in the direction of nitrous oxide reduction. Contains the mixed-valent dinuclear CuA species at the electron entry site of the enzyme, and the tetranuclear Cu-Z centre in the active site. In Paracoccus pantotrophus, the electron donor is cytochrome c552.

Links to other databases: BRENDA, EAWAG-BBD, EXPASY, KEGG, Metacyc, PDB, CAS registry number: 55576-44-8

References:

1. Coyle, C.L., Zumft, W.G., Kroneck, P.M.H., Körner, H. and Jakob, W. Nitrous oxide reductase from denitrifying Pseudomonas perfectomarina. Purification and properties of a novel multicopper enzyme. Eur. J. Biochem. 153 (1985) 459-467. [PMID: 3000778]

2. Zumft, W.G. and Kroneck, P.M. Respiratory transformation of nitrous oxide (N2O) to dinitrogen by bacteria and archaea. Adv. Microb. Physiol. 52 (2007) 107-227. [PMID: 17027372]

3. Dell'Acqua, S., Pauleta, S.R., Paes de Sousa, P.M., Monzani, E., Casella, L., Moura, J.J. and Moura, I. A new CuZ active form in the catalytic reduction of N2O by nitrous oxide reductase from Pseudomonas nautica. J. Biol. Inorg. Chem. 15 (2010) 967-976. [PMID: 20422435]

[EC 1.7.2.4 created 1989 as EC 1.7.99.6, modified 1999, transferred 2011 to EC 1.7.2.4]

EC 1.7.2.5

Accepted name: nitric oxide reductase (cytochrome c)

Reaction: nitrous oxide + 2 ferricytochrome c + H2O = 2 nitric oxide + 2 ferrocytochrome c + 2 H+

Systematic name: nitrous oxide:ferricytochrome-c oxidoreductase

Comments: The enzyme from Pseudomonas aeruginosa contains a dinuclear centre comprising a non-heme iron centre and heme b3, plus heme c, heme b and calcium; the acceptor is cytochrome c551

Links to other databases: BRENDA, EAWAG-BBD, EXPASY, KEGG, Metacyc, PDB, CAS registry number:

References:

1. Hendriks, J., Warne, A., Gohlke, U., Haltia, T., Ludovici, C., Lubben, M. and Saraste, M. The active site of the bacterial nitric oxide reductase is a dinuclear iron center. Biochemistry 37 (1998) 13102-13109. [PMID: 9748316]

2. Hendriks, J., Gohlke, U. and Saraste, M. From NO to OO: nitric oxide and dioxygen in bacterial respiration. J. Bioenerg. Biomembr. 30 (1998) 15-24. [PMID: 9623801]

3. Heiss, B., Frunzke, K. and Zumpft, W.G. Formation of the N-N bond from nitric oxide by a membrane-bound cytochrome bc complex of nitrate-respiring (denitrifying) Pseudomonas stutzeri. J. Bacteriol. 171 (1989) 3288-3297. [PMID: 2542222]

4. Cheesman, M.R., Zumft, W.G. and Thomson, A.J. The MCD and EPR of the heme centers of nitric oxide reductase from Pseudomonas stutzeri: evidence that the enzyme is structurally related to the heme-copper oxidases. Biochemistry 37 (1998) 3994-4000. [PMID: 9521721]

5. Kumita, H., Matsuura, K., Hino, T., Takahashi, S., Hori, H., Fukumori, Y., Morishima, I. and Shiro, Y. NO reduction by nitric-oxide reductase from denitrifying bacterium Pseudomonas aeruginosa: characterization of reaction intermediates that appear in the single turnover cycle. J. Biol. Chem. 279 (2004) 55247-55254. [PMID: 15504726]

6. Hino, T., Matsumoto, Y., Nagano, S., Sugimoto, H., Fukumori, Y., Murata, T., Iwata, S. and Shiro, Y. Structural basis of biological N2O generation by bacterial nitric oxide reductase. Science 330 (2010) 1666-1670. [PMID: 21109633]

[EC 1.7.2.5 created 1992 as EC 1.7.99.7, transferred 2011 to EC 1.7.2.5]

EC 1.7.2.6

Accepted name: hydroxylamine dehydrogenase

Reaction: hydroxylamine + H2O + 4 ferricytochrome c = nitrite + 4 ferrocytochrome c + 5 H+

Other name(s): HAO (ambiguous); hydroxylamine oxidoreductase (ambiguous); hydroxylamine oxidase (misleading)

Systematic name: hydroxylamine:ferricytochrome-c oxidoreductase (nitrite-forming)

Comments: The enzymes from the nitrifying bacterium Nitrosomonas europaea [1,4] and the methylotrophic bacterium Methylococcus capsulatus [5] are hemoproteins with seven c-type hemes and one specialized P-460-type heme per subunit. The enzyme converts hydroxylamine to nitrite via an enzyme-bound nitroxyl intermediate [3]. While nitrite is the main product, the enzyme from Nitrosomonas europaea can also produce nitric oxide by catalysing the activity of EC 1.7.2.9, hydroxylamine oxidase [2].

Links to other databases: BRENDA, EXPASY, KEGG, MetaCyc, PDB, CAS registry number: 9075-43-8

References:

1. Rees, M. Studies of the hydroxylamine metabolism of Nitrosomonas europaea. I. Purification of hydroxylamine oxidase. Biochemistry 7 (1968) 353-366. [PMID: 5758552]

2. Hooper, A.B. and Terry, K.R. Hydroxylamine oxidoreductase of Nitrosomonas. Production of nitric oxide from hydroxylamine. Biochim. Biophys. Acta 571 (1979) 12-20. [PMID: 497235]

3. Hooper, A.B. and Balny, C. Reaction of oxygen with hydroxylamine oxidoreductase of Nitrosomonas: fast kinetics. FEBS Lett. 144 (1982) 299-303. [PMID: 7117545]

4. Lipscomb, J.D. and Hooper, A.B. Resolution of multiple heme centers of hydroxylamine oxidoreductase from Nitrosomonas. 1. Electron paramagnetic resonance spectroscopy. Biochemistry 21 (1982) 3965-3972. [PMID: 6289867]

5. Poret-Peterson, A.T., Graham, J.E., Gulledge, J. and Klotz, M.G. Transcription of nitrification genes by the methane-oxidizing bacterium, Methylococcus capsulatus strain Bath. ISME J. 2 (2008) 1213-1220. [PMID: 18650926]

[EC 1.7.2.6 created 1972 as EC 1.7.3.4, part transferred 2012 to EC 1.7.2.6, modifed 2021, modified 2021]

EC 1.7.2.7

Accepted name: hydrazine synthase

Reaction: hydrazine + H2O + 3 ferricytochrome c = nitric oxide + ammonium + 3 ferrocytochrome c

Glossary: nitric oxide = nitrogen monoxide = NO

Other name(s): HZS

Systematic name: hydrazine:ferricytochrome-c oxidoreductase

Comments: The enzyme, characterized from anaerobic ammonia oxidizers (anammox bacteria), is one of only a few enzymes that are known to form an N-N bond (other examples include EC 1.7.1.14, nitric oxide reductase [NAD(P)+, nitrous oxide-forming] and EC 4.8.1.1, L-piperazate synthase). The enzyme from the bacterium Candidatus Kuenenia stuttgartiensis is a dimer of heterotrimers and contains multiple c-type cytochromes.

Links to other databases: BRENDA, EXPASY, KEGG, MetaCyc, PDB, CAS registry number:

References:

1. Kartal, B., Maalcke, W.J., de Almeida, N.M., Cirpus, I., Gloerich, J., Geerts, W., Op den Camp, H.J., Harhangi, H.R., Janssen-Megens, E.M., Francoijs, K.J., Stunnenberg, H.G., Keltjens, J.T., Jetten, M.S. and Strous, M. Molecular mechanism of anaerobic ammonium oxidation. Nature 479 (2011) 127-130. [PMID: 21964329]

2. Dietl, A., Ferousi, C., Maalcke, W.J., Menzel, A., de Vries, S., Keltjens, J.T., Jetten, M.S., Kartal, B. and Barends, T.R. The inner workings of the hydrazine synthase multiprotein complex. Nature 527 (2015) 394-397. [PMID: 26479033]

[EC 1.7.2.7 created 2016, modified 2021]

EC 1.7.2.8

Accepted name: hydrazine dehydrogenase

Reaction: hydrazine + 4 ferricytochrome c = N2 + 4 ferrocytochrome c

Other name(s): HDH

Systematic name: hydrazine:ferricytochrome c oxidoreductase

Comments: The enzyme, which is involved in the pathway of anaerobic ammonium oxidation in anammox bacteria, has been purified from the bacterium Candidatus Kuenenia stuttgartiensis. The electrons derived from hydrazine are eventually transferred to the quinone pool.

Links to other databases: BRENDA, EXPASY, KEGG, MetaCyc, PDB, CAS registry number:

References:

1. Schalk, J., de Vries, S., Kuenen, J.G. and Jetten, M.S. Involvement of a novel hydroxylamine oxidoreductase in anaerobic ammonium oxidation. Biochemistry 39 (2000) 5405-5412. [PMID: 10820012]

2. Jetten, M.S., Wagner, M., Fuerst, J., van Loosdrecht, M., Kuenen, G. and Strous, M. Microbiology and application of the anaerobic ammonium oxidation ('anammox') process. Curr. Opin. Biotechnol. 12 (2001) 283-288. [PMID: 11404106]

3. Kartal, B., Maalcke, W.J., de Almeida, N.M., Cirpus, I., Gloerich, J., Geerts, W., Op den Camp, H.J., Harhangi, H.R., Janssen-Megens, E.M., Francoijs, K.J., Stunnenberg, H.G., Keltjens, J.T., Jetten, M.S. and Strous, M. Molecular mechanism of anaerobic ammonium oxidation. Nature 479 (2011) 127-130. [PMID: 21964329]

4. Kartal, B., de Almeida, N.M., Maalcke, W.J., Op den Camp, H.J., Jetten, M.S. and Keltjens, J.T. How to make a living from anaerobic ammonium oxidation. FEMS Microbiol. Rev. 37 (2013) 428-461. [PMID: 23210799]

[EC 1.7.2.8 created 2003 as EC 1.7.99.8, modified 2010, transferred 2016 to EC 1.7.2.8]

EC 1.7.2.9

Accepted name: hydroxylamine oxidase

Reaction: hydroxylamine + 3 ferricytochrome c = nitric oxide + 3 ferrocytochrome c + 3 H+

Other name(s): HOX

Systematic name: hydroxylamine:ferricytochrome-c oxidoreductase (nitric acid-forming)

Comments: The enzyme, characterized from the anaerobic ammonium-oxidizing (anammox) bacterium Kuenenia stuttgartiensis, is very similar to EC 1.7.2.6, hydroxylamine dehydrogenase. Both enzymes are homotrimeric enzymes in which each subunit contains seven c-type hemes and one specialized P460-type heme that is bound to a tyrosine residue in an adjacent subunit. However, this enzyme catalyses only the 3 electron oxidation of hydroxylamine, forming nitric oxide, and is not capable of performing further oxidation to form nitrite.

Links to other databases: BRENDA, EXPASY, KEGG, MetaCyc, CAS registry number:

References:

1. Maalcke, W.J., Dietl, A., Marritt, S.J., Butt, J.N., Jetten, M.S., Keltjens, J.T., Barends, T.R. and Kartal, B. Structural basis of biological NO generation by octaheme oxidoreductases. J. Biol. Chem. 289 (2014) 1228-1242. [PMID: 24302732]

[EC 1.7.2.9 created 2021]


EC 1.7.3 With oxygen as acceptor

Contents

EC 1.7.3.1 nitroalkane oxidase
EC 1.7.3.2 acetylindoxyl oxidase
EC 1.7.3.3 factor-independent urate hydroxylase oxidase
EC 1.7.3.4 deleted now covered by EC 1.7.2.6 and EC 1.7.3.6
EC 1.7.3.5 3-aci-nitropropanoate oxidase

EC 1.7.3.6 hydroxylamine oxidase (cytochrome)


EC 1.7.3.1

Accepted name: nitroalkane oxidase

Reaction: a nitroalkane + H2O + O2 = an aldehyde or ketone + nitrite + H2O2

Other name(s): nitroethane oxidase; NAO; nitroethane:oxygen oxidoreductase

Systematic name: nitroalkane:oxygen oxidoreductase

Comments: Has an absolute requirement for FAD [4]. While nitroethane may be the physiological substrate [2], the enzyme also acts on several other nitroalkanes, including 1-nitropropane, 2-nitropropane, 1-nitrobutane, 1-nitropentane, 1-nitrohexane, nitrocyclohexane and some nitroalkanols [4]. Differs from EC 1.13.12.16, nitronate monooxygenase, in that the preferred substrates are neutral nitroalkanes rather than anionic nitronates [4].

Links to other databases: BRENDA, EXPASY, KEGG, Metacyc, PDB, CAS registry number: 9029-36-1, 65802-82-6

References:

1. Little, H.N. Oxidation of nitroethane by extracts from Neurospora. J. Biol. Chem. 193 (1951) 347-358. [PMID: 14907722]

2. Kido, T., Hashizume, K. and Soda, K. Purification and properties of nitroalkane oxidase from Fusarium oxysporum. J. Bacteriol. 133 (1978) 53-58. [PMID: 22538]

3. Daubner, S.C., Gadda, G., Valley, M.P. and Fitzpatrick, P.F. Cloning of nitroalkane oxidase from Fusarium oxysporum identifies a new member of the acyl-CoA dehydrogenase superfamily. Proc. Natl. Acad. Sci. USA 99 (2002) 2702-2707. [PMID: 11867731]

4. Fitzpatrick, P.F., Orville, A.M., Nagpal, A. and Valley, M.P. Nitroalkane oxidase, a carbanion-forming flavoprotein homologous to acyl-CoA dehydrogenase. Arch. Biochem. Biophys. 433 (2005) 157-165. [PMID: 15581574]

5. Valley, M.P., Tichy, S.E. and Fitzpatrick, P.F. Establishing the kinetic competency of the cationic imine intermediate in nitroalkane oxidase. J. Am. Chem. Soc. 127 (2005) 2062-2066. [PMID: 15713081]

[EC 1.7.3.1 created 1961, modified 2006, modified 2009]

EC 1.7.3.2

Accepted name: acetylindoxyl oxidase

Reaction: N-acetylindoxyl + O2 = N-acetylisatin + (?)

Systematic name: N-acetylindoxyl:oxygen oxidoreductase

Links to other databases: BRENDA, EXPASY, KEGG, Metacyc, CAS registry number: 9029-37-2

References:

1. Beevers, H. and French, R.C. Oxidation of N-acetylindoxyl by an enzyme from plants. Arch. Biochem. Biophys. 50 (1954) 427-439.

[EC 1.7.3.2 created 1961]

EC 1.7.3.3

Accepted name: factor-independent urate hydroxylase

Reaction: urate + O2 + H2O = 5-hydroxyisourate + H2O2

For diagram of reaction, click here

Other name(s): uric acid oxidase; uricase; uricase II; urate oxidase

Systematic name: urate:oxygen oxidoreductase

Comments: This enzyme was previously thought to be a copper protein, but it is now known that the enzymes from soy bean (Glycine max), the mould Aspergillus flavus and Bacillus subtilis contains no copper nor any other transition-metal ion. The 5-hydroxyisourate formed decomposes spontaneously to form allantoin and CO2, although there is an enzyme-catalysed pathway in which EC 3.5.2.17, hydroxyisourate hydrolase, catalyses the first step. The enzyme is different from EC 1.14.13.113 (FAD-dependent urate hydroxylase).

Links to other databases: BRENDA, EAWAG-BBD, EXPASY, KEGG, Metacyc, PDB, CAS registry number: 9002-12-4

References:

1. London, M. and Hudson, P.B. Purification and properties of solubilized uricase. Biochim. Biophys. Acta 21 (1956) 290-298. [PMID: 13363909]

2. Mahler, H.R., Hübscher, G. and Baum, H. Studies on uricase. I. Preparation, purification, and properties of a cuproprotein. J. Biol. Chem. 216 (1955) 625-641. [PMID: 13271340]

3. Robbins, K.C., Barnett, E.L. and Grant, N.H. Partial purification of porcine liver uricase. J. Biol. Chem. 216 (1955) 27-35. [PMID: 13252004]

4. Kahn, K. and Tipton, P.A. Spectroscopic characterization of intermediates in the urate oxidase reaction. Biochemistry 37 (1998) 11651-11659. [PMID: 9709003]

5. Colloc'h, N., el Hajji, M., Bachet, B., L'Hermite, G., Schiltz, M., Prange, T., Castro, B. and Mornon, J.-P. Crystal structure of the protein drug urate oxidase-inhibitor complex at 2.05 Å resolution. Nat. Struct. Biol. 4 (1997) 947-952. [PMID: 9360612]

6. Imhoff, R.D., Power, N.P., Borrok, M.J. and Tipton, P.A. General base catalysis in the urate oxidase reaction: evidence for a novel Thr-Lys catalytic diad. Biochemistry 42 (2003) 4094-4100. [PMID: 12680763]

[EC 1.7.3.3 created 1961, modified 2002, modified 2005, modified 2010]

[EC 1.7.3.4 Transferred entry: hydroxylamine oxidase. Now covered by EC 1.7.2.6, hydroxylamine dehydrogenase, and EC 1.7.3.6, hydroxylamine oxidase (cytochrome) (EC 1.7.3.4 created 1972, deleted 2013)]

EC 1.7.3.5

Accepted name: 3-aci-nitropropanoate oxidase

Reaction: 3-aci-nitropropanoate + O2 + H2O = 3-oxopropanoate + nitrite + H2O2

Other name(s): propionate-3-nitronate oxidase

Systematic name: 3-aci-nitropropanoate:oxygen oxidoreductase

Comments: A flavoprotein (FMN). The primary products of the enzymic reaction are probably the nitropropanoate free radical and superoxide. Also acts, more slowly, on 4-aci-nitrobutanoate.

Links to other databases: BRENDA, EXPASY, KEGG, Metacyc, CAS registry number: 111940-52-4

References:

1. Porter, D.J.T. and Bright, H.J. Propionate-3-nitronate oxidase from Penicillium atrovenetum is a flavoprotein which initiates the autoxidation of its substrate by O2. J. Biol. Chem. 262 (1987) 14428-14434. [PMID: 3667582]

[EC 1.7.3.5 created 1990]

EC 1.7.3.6

Accepted name: hydroxylamine oxidase (cytochrome)

Reaction: hydroxylamine + O2 = nitrite + H2O + H+ (overall reaction)
(1a) hydroxylamine + 2 ferricytochrome c = nitroxyl + 2 ferrocytochrome c + 2 H+
(1b) nitroxyl + 2 ferrocytochrome c + O2 + H+ = nitrite + 2 ferricytochrome c + H2O (spontaneous)

Other name(s): HAO (ambiguous); hydroxylamine oxidoreductase (ambiguous); hydroxylamine oxidase (misleading)

Systematic name: hydroxylamine:oxygen oxidoreductase

Comments: The enzyme from the heterotrophic nitrifying bacterium Paracoccus denitrificans contains three to five non-heme, non-iron-sulfur iron atoms and interacts with cytochrome c556 and pseudoazurin [2,3]. Under anaerobic conditions in vitro only nitrous oxide is formed [3]. Presumably nitroxyl is released and combines with a second nitroxyl to give nitrous oxide and water. When oxygen is present, nitrite is formed.

Links to other databases: BRENDA, EXPASY, KEGG, MetaCyc, PDB, CAS registry number: 9075-43-8

References:

1. Kurokawa, M, Fukumori, Y and Yamanaka, T A hydroxylamine - cytochrome c reductase occurs in the heterotrophic nitrifier Arthrobacter globiformis. Plant Cell Physiol 26 (1985) 1439-1442.

2. Wehrfritz, J.M., Reilly, A., Spiro, S. and Richardson, D.J. Purification of hydroxylamine oxidase from Thiosphaera pantotropha. Identification of electron acceptors that couple heterotrophic nitrification to aerobic denitrification. FEBS Lett 335 (1993) 246-250. [PMID: 8253206]

3. Moir, J.W., Wehrfritz, J.M., Spiro, S. and Richardson, D.J. The biochemical characterization of a novel non-haem-iron hydroxylamine oxidase from Paracoccus denitrificans GB17. Biochem. J. 319 (1996) 823-827. [PMID: 8920986]

4. Wehrfritz, J., Carter, J.P., Spiro, S. and Richardson, D.J. Hydroxylamine oxidation in heterotrophic nitrate-reducing soil bacteria and purification of a hydroxylamine-cytochrome c oxidoreductase from a Pseudomonas species. Arch. Microbiol. 166 (1996) 421-424. [PMID: 9082922]

[EC 1.7.3.6 created 1972 as EC 1.7.3.4, part transferred 2013 to EC 1.7.3.6, modified 2015]


EC 1.7.5 With a quinone or similar compound as acceptor

Contents

EC 1.7.5.1 nitrate reductase (quinone)
EC 1.7.5.2 nitric oxide reductase (menaquinol)


EC 1.7.5.1

Accepted name: nitrate reductase (quinone)

Reaction: nitrate + a quinol = nitrite + a quinone + H2O

Other name(s): nitrate reductase A; nitrate reductase Z; quinol/nitrate oxidoreductase; quinol-nitrate oxidoreductase; quinol:nitrate oxidoreductase; NarA; NarZ; NarGHI; dissimilatory nitrate reductase

Systematic name: nitrite:quinone oxidoreductase

Comments: A membrane-bound enzyme which supports anaerobic respiration on nitrate under anaerobic conditions and in the presence of nitrate. Contains the bicyclic form of the molybdo-bis(molybdopterin guanine dinucleotide) cofactor, iron-sulfur clusters and heme b. Escherichia coli expresses two forms NarA and NarZ, both being comprised of three subunits.

Links to other databases: BRENDA, EXPASY, KEGG, Metacyc, CAS registry number:

References:

1. Enoch, H.G. and Lester, R.L. The role of a novel cytochrome b-containing nitrate reductase and quinone in the in vitro reconstruction of formate-nitrate reductase activity of E. coli. Biochem. Biophys. Res. Commun. 61 (1974) 1234-1241. [PMID: 4616697]

2. Bertero, M.G., Rothery, R.A., Palak, M., Hou, C., Lim, D., Blasco, F., Weiner, J.H. and Strynadka, N.C. Insights into the respiratory electron transfer pathway from the structure of nitrate reductase A. Nat. Struct. Biol. 10 (2003) 681-687. [PMID: 12910261]

3. Lanciano, P., Magalon, A., Bertrand, P., Guigliarelli, B. and Grimaldi, S. High-stability semiquinone intermediate in nitrate reductase A (NarGHI) from Escherichia coli is located in a quinol oxidation site close to heme bD. Biochemistry 46 (2007) 5323-5329. [PMID: 17439244]

4. Bertero, M.G., Rothery, R.A., Boroumand, N., Palak, M., Blasco, F., Ginet, N., Weiner, J.H. and Strynadka, N.C. Structural and biochemical characterization of a quinol binding site of Escherichia coli nitrate reductase A. J. Biol. Chem. 280 (2005) 14836-14843. [PMID: 15615728]

5. Bonnefoy, V. and Demoss, J.A. Nitrate reductases in Escherichia coli. Antonie Van Leeuwenhoek 66 (1994) 47-56. [PMID: 7747940]

6. Guigliarelli, B., Asso, M., More, C., Augier, V., Blasco, F., Pommier, J., Giordano, G. and Bertrand, P. EPR and redox characterization of iron-sulfur centers in nitrate reductases A and Z from Escherichia coli. Evidence for a high-potential and a low-potential class and their relevance in the electron-transfer mechanism. Eur. J. Biochem. 207 (1992) 61-68. [PMID: 1321049]

[EC 1.7.5.1 created 2010]

EC 1.7.5.2

Accepted name: nitric oxide reductase (menaquinol)

Reaction: 2 nitric oxide + menaquinol = nitrous oxide + menaquinone + H2O

Comments: Contains copper.

Links to other databases: BRENDA, EXPASY, KEGG, Metacyc, PDB, CAS registry number:

References:

1. Cramm, R., Pohlmann, A. and Friedrich, B. Purification and characterization of the single-component nitric oxide reductase from Ralstonia eutropha H16. FEBS Lett. 460 (1999) 6-10. [PMID: 10571051]

2. Suharti, Strampraad, M.J., Schroder, I. and de Vries, S. A novel copper A containing menaquinol NO reductase from Bacillus azotoformans. Biochemistry 40 (2001) 2632-2639. [PMID: 11327887]

3. Suharti, Heering, H.A. and de Vries, S. NO reductase from Bacillus azotoformans is a bifunctional enzyme accepting electrons from menaquinol and a specific endogenous membrane-bound cytochrome c551. Biochemistry 43 (2004) 13487-13495. [PMID: 15491156]

[EC 1.7.5.2 created 2011]


EC 1.7.6With a nitrogenous group as acceptor

EC 1.7.6.1

Accepted name: nitrite dismutase

Reaction: 3 nitrite + 2 H+ = 2 nitric oxide + nitrate + H2O

Other name(s): Prolixin S; Nitrophorin 7

Systematic name: nitrite:nitrite oxidoreductase

Comments: Contains ferriheme b. The enzyme is one of the nitrophorins from the salivary gland of the blood-feeding insect Rhodnius prolixus. Nitric oxide produced induces vasodilation after injection. Nitrophorins 2 and 4 can also catalyse this reaction.

Links to other databases: BRENDA, EXPASY, KEGG, Metacyc, PDB, CAS registry number:

References:

1. He, C. and Knipp, M. Formation of nitric oxide from nitrite by the ferriheme b protein nitrophorin 7. J. Am. Chem. Soc. 131 (2009) 12042-12043. [PMID: 19655755]

2. He, C., Ogata, H. and Knipp, M. Formation of the complex of nitrite with the ferriheme b β-barrel proteins nitrophorin 4 and nitrophorin 7. Biochemistry 49 (2010) 5841-5851. [PMID: 20524697]

[EC 1.7.6.1 created 2011]


EC 1.7.7 With an iron-sulfur protein as acceptor

Contents

EC 1.7.7.1 ferredoxin—nitrite reductase
EC 1.7.7.2 ferredoxin—nitrate reductase


EC 1.7.7.1

Accepted name: ferredoxin—nitrite reductase

Reaction: NH3 + 2 H2O + 6 oxidized ferredoxin = nitrite + 6 reduced ferredoxin + 7 H+

Systematic name: ammonia:ferredoxin oxidoreductase

Comments: An iron protein. Contains siroheme and [4Fe-4S] clusters.

Links to other databases: BRENDA, EXPASY, KEGG, Metacyc, PDB, CAS registry number: 37256-44-3

References:

1. Joy, K.W. and Hageman, R.H. The purification and properties of nitrite reductase from higher plants, and its dependence on ferredoxin. Biochem. J. 100 (1966) 263-273. [PMID: 4381617]

2. Ramirez, J.M., Del Campo, F.F., Paneque, A. and Losada, M. Ferredoxin-nitrite reductase from spinach. Biochim. Biophys. Acta 118 (1966) 58-71. [PMID: 5954064]

3. Zumft, W.G., Paneque, A., Aparicio, P.J. and Losada, M. Mechanism of nitrate reduction in Chlorella. Biochem. Biophys. Res. Commun. 36 (1969) 980-986. [PMID: 4390523]

[EC 1.7.7.1 created 1972, modified 1999]

EC 1.7.7.2

Accepted name: ferredoxin—nitrate reductase

Reaction: nitrite + H2O + 2 oxidized ferredoxin = nitrate + 2 reduced ferredoxin + 2 H+

Other name(s): assimilatory nitrate reductase (ambiguous); nitrate (ferredoxin) reductase; assimilatory ferredoxin-nitrate reductase

Systematic name: nitrite:ferredoxin oxidoreductase

Comments: A molybdenum-iron-sulfur protein.

Links to other databases: BRENDA, EAWAG-BBD, EXPASY, KEGG, Metacyc, PDB, CAS registry number: 60382-69-6

References:

1. Mikami, B. and Ida, S. Purification and properties of ferrodoxin-nitrate reductase from the cyanobacterium Plectonema borganum. Biochim. Biophys. Acta 791 (1984) 294-304.

[EC 1.7.7.2 created 1986]


EC 1.7.99 With unknown physiological acceptors

Contents

EC 1.7.99.1 hydroxylamine reductase
EC 1.7.99.2 deleted
EC 1.7.99.3 included with EC 1.7.2.1
EC 1.7.99.4 transferred, now EC 1.7.1.1, EC 1.7.1.2, EC 1.7.1.3, EC 1.7.5.1, EC 1.7.7.2 and EC 1.9.6.1
EC 1.7.99.5 included with EC 1.5.1.20
EC 1.7.99.6 transferred now EC 1.7.2.4
EC 1.7.99.7 transferred now EC 1.7.2.5
EC 1.7.99.8 hydrazine oxidoreductase
EC 1.7.99.8 transferred, now EC 1.7.2.8


EC 1.7.99.1

Accepted name: hydroxylamine reductase

Reaction: NH3 + H2O + acceptor = hydroxylamine + reduced acceptor

Other name(s): hydroxylamine (acceptor) reductase; ammonia:(acceptor) oxidoreductase

Systematic name: ammonia:acceptor oxidoreductase

Comments: A flavoprotein. Reduced pyocyanine, methylene blue and flavins act as donors for the reduction of hydroxylamine. May be identical to EC 1.7.2.1, nitrite reductase (NO-forming).

Links to other databases: BRENDA, EXPASY, KEGG, Metacyc, PDB, CAS registry number: 37256-42-1

References:

1. Taniguchi, H., Mitsui, H., Nakamura, K. and Egami, F. Hydoxylamine reductase. Ann. Acad. Sci. Fenn. Ser. A II 60 (1955) 200-215.

2. Walker, G.C. and Nicholas, D.J.D. Hydroxylamine reductase from Pseudomonas aeruginosa. Biochim. Biophys. Acta 49 (1961) 361-368.

3. Richter, C.D., Allen, J.W., Higham, C.W., Koppenhofer, A., Zajicek, R.S., Watmough, N.J. and Ferguson, S.J. Cytochrome cd1, reductive activation and kinetic analysis of a multifunctional respiratory enzyme. J. Biol. Chem. 277 (2002) 3093-3100.[PMID: 11709555]

[EC 1.7.99.1 created 1961, modified 1999, modified 2002]

[EC 1.7.99.2 Deleted entry: nitric-oxide reductase. Reaction may have been due to the combined action of EC 1.7.99.6 nitrous-oxide reductase and EC 1.7.99.7 nitric-oxide reductase (EC 1.7.99.2 created 1961, modified 1976, deleted 1992)]

[EC 1.7.99.3 Transferred entry: now included with EC 1.7.2.1, nitrite reductase (NO-forming) (EC 1.7.99.3 created 1961 as EC 1.6.6.5, transferred 1964 to EC 1.7.99.3, modified 1976, deleted 2002)]

[EC 1.7.99.4 Transferred entry: nitrate reductase, Now EC 1.7.1.1, nitrate reductase (NADH), EC 1.7.1.2, nitrate reductase [NAD(P)H], EC 1.7.1.3, nitrate reductase (NADPH), EC 1.7.5.1, nitrate reductase (quinone), EC 1.7.7.2, nitrate reductase (ferredoxin), and EC 1.9.6.1, nitrate reductase (cytochrome) (EC 1.7.99.4 created 1972, modified 1976, deleted 2017)]

[EC 1.7.99.5 Deleted entry: 5,10-methylenetetrahydrofolate reductase (FADH2). Now included with EC 1.5.1.20, methylenetetrahydrofolate reductase [NAD(P)H]. Based on the reference, it had been thought that this was a separate enzyme from EC 1.5.1.20 but the reference upon which the entry was based has since been disproved. (EC 1.7.99.5 created 1965 as EC 1.1.1.68, transferred 1978 to EC 1.1.99.15, transferred 1980 to EC 1.7.99.5, deleted 2005)]

[EC 1.7.99.6 Transferred entry: nitrous-oxide reductase. Now EC 1.7.2.4, nitrous-oxide reductase (EC 1.7.99.6 created 1989, modified 1999, deleted 2011)]

[EC 1.7.99.7 Transferred entry: nitric-oxide reductase. Now EC 1.7.2.5 nitric oxide reductase (cytochrome c) (EC 1.7.99.7 created 1992, modified 1999, deleted 2011)]

[EC 1.7.99.8 Transferred entry: hydrazine oxidoreductase, now classified as EC 1.7.2.8, hydrazine dehydrogenase. (EC 1.7.99.8 created 2003, modified 2010, deleted 2016)]


EC 1.8 ACTING ON A SULFUR GROUP OF DONORS

Sections

EC 1.8.1 With NAD+ or NADP+ as acceptor
EC 1.8.2 With a cytochrome as acceptor
EC 1.8.3 With oxygen as acceptor
EC 1.8.4 With a disulfide as acceptor
EC 1.8.5 With a quinone as acceptor
EC 1.8.6 With nitrogenous group as acceptor
EC 1.8.7 With an iron-sulfur protein as acceptor
EC 1.8.98 With other, known, physiological acceptors

EC 1.8.99 With unknown physiological acceptors


EC 1.8.1 With NAD+ or NADP+ as acceptor

Contents

EC 1.8.1.1 deleted
EC 1.8.1.2 sulfite reductase (NADPH)
EC 1.8.1.3 assimilatory sulfite reductase (NADPH)
EC 1.8.1.3 deleted
EC 1.8.1.4 dihydrolipoyl dehydrogenase
EC 1.8.1.5 2-oxopropyl-CoM reductase (carboxylating)
EC 1.8.1.6 cystine reductase
EC 1.8.1.7 glutathione-disulfide reductase
EC 1.8.1.8 protein-disulfide reductase
EC 1.8.1.9 thioredoxin-disulfide reductase
EC 1.8.1.10 CoA-glutathione reductase
EC 1.8.1.11 asparagusate reductase
EC 1.8.1.12 trypanothione-disulfide reductase
EC 1.8.1.13 bis-γ-glutamylcystine reductase
EC 1.8.1.14 CoA-disulfide reductase
EC 1.8.1.15 mycothione reductase
EC 1.8.1.16 glutathione amide reductase
EC 1.8.1.17 dimethylsulfone reductase
EC 1.8.1.18 NAD(P)H sulfur oxidoreductase (CoA-dependent)
EC 1.8.1.19 sulfide dehydrogenase
EC 1.8.1.20 4,4'-dithiodibutanoate disulfide reductase
EC 1.8.1.21 dissimilatory dimethyldisulfide reductase
EC 1.8.1.22 dissimilatory sulfite reductase system


[EC 1.8.1.1 Deleted entry: cysteamine dehydrogenase (EC 1.8.1.1 created 1961, deleted 1972)]

EC 1.8.1.2

Accepted name: assimilatory sulfite reductase (NADPH)

Reaction: hydrogen sulfide + 3 NADP+ + 3 H2O = sulfite + 3 NADPH + 3 H+

Other name(s): sulfite reductase (NADPH); sulfite (reduced nicotinamide adenine dinucleotide phosphate) reductase; NADPH-sulfite reductase; NADPH-dependent sulfite reductase; H2S-NADP oxidoreductase; sulfite reductase (NADPH2); MET5 (gene name); MET10 (gene name); cysI (gene name); cysJ (gene name)

Systematic name: hydrogen-sulfide:NADP+ oxidoreductase

Comments: Contains siroheme, [4Fe-4S] cluster, FAD and FMN. The enzyme, which catalyses the six-electron reduction of sulfite to sulfide, is involved in sulfate assimilation in bacteria and yeast. Different from EC 1.8.99.5, dissimilatory sulfite reductase, which is involved in prokaryotic sulfur-based energy metabolism. cf. EC 1.9.7.1, assimilatory sulfite reductase (ferredoxin).

Links to other databases: BRENDA, EXPASY, KEGG, MetaCyc, PDB, CAS registry number: 9029-35-0

References:

1. Hilz, H., Kittler, M. and Knape, G. Die Reduktion von Sulfate in der Hefe. Biochem. Z. 332 (1959) 151-166. [PMID: 14401842]

2. Yoshimoto, A. and Sato, R. Studies on yeast sulfite reductase. I. Purification and characterization. Biochim. Biophys. Acta 153 (1968) 555-575. [PMID: 4384979]

3. Siegel, L.M., Murphy, M.J. and Kamin, H. Reduced nicotinamide adenine dinucleotide phosphate-sulfite reductase of enterobacteria. I. The Escherichia coli hemoflavoprotein: molecular parameters and prosthetic groups. J. Biol. Chem. 248 (1973) 251-264. [PMID: 4144254]

4. Kobayashi, K. and Yoshimoto, A. Studies on yeast sulfite reductase. IV. Structure and steady-state kinetics. Biochim. Biophys. Acta 705 (1982) 348-356. [PMID: 6751400]

5. Siegel, L.M., Rueger, D.C., Barber, M.J., Krueger, R.J., Orme-Johnson, N.R. and Orme-Johnson, W.H. Escherichia coli sulfite reductase hemoprotein subunit. Prosthetic groups, catalytic parameters, and ligand complexes. J. Biol. Chem. 257 (1982) 6343-6350. [PMID: 6281269]

6. Coves, J., Zeghouf, M., Macherel, D., Guigliarelli, B., Asso, M. and Fontecave, M. Flavin mononucleotide-binding domain of the flavoprotein component of the sulfite reductase from Escherichia coli. Biochemistry 36 (1997) 5921-5928. [PMID: 9153434]

7. Crane, B.R., Siegel, L.M. and Getzoff, E.D. Structures of the siroheme- and Fe4S4-containing active center of sulfite reductase in different states of oxidation: heme activation via reduction-gated exogenous ligand exchange. Biochemistry 36 (1997) 12101-12119. [PMID: 9315848]

[EC 1.8.1.2 created 1961, modified 2015]

[EC 1.8.1.3 Deleted entry: hypotaurine dehydrogenase. The reaction is now known to be catalyzed by EC 1.14.13.8, flavin-containing monooxygenase. (EC 1.8.1.3 created 1972, deleted 2022)]

EC 1.8.1.4

Accepted name: dihydrolipoyl dehydrogenase

Reaction: protein N6-(dihydrolipoyl)lysine + NAD+ = protein N6-(lipoyl)lysine + NADH + H+

For diagram, click here, here or here

Glossary: dihydrolipoyl group

Other name(s): LDP-Glc; LDP-Val; dehydrolipoate dehydrogenase; diaphorase; dihydrolipoamide dehydrogenase; dihydrolipoamide:NAD+ oxidoreductase; dihydrolipoic dehydrogenase; dihydrothioctic dehydrogenase; lipoamide dehydrogenase (NADH); lipoamide oxidoreductase (NADH); lipoamide reductase; lipoamide reductase (NADH); lipoate dehydrogenase; lipoic acid dehydrogenase; lipoyl dehydrogenase

Systematic name: protein-N6-(dihydrolipoyl)lysine:NAD+ oxidoreductase

Comments: A flavoprotein (FAD). A component of the multienzyme 2-oxo-acid dehydrogenase complexes. In the pyruvate dehydrogenase complex, it binds to the core of EC 2.3.1.12, dihydrolipoyllysine-residue acetyltransferase, and catalyses oxidation of its dihydrolipoyl groups. It plays a similar role in the oxoglutarate and 3-methyl-2-oxobutanoate dehydrogenase complexes. Another substrate is the dihydrolipoyl group in the H-protein of the glycine-cleavage system (click here for diagram), in which it acts, together with EC 1.4.4.2, glycine dehydrogenase (decarboxylating), and EC 2.1.2.10, aminomethyltransferase, to break down glycine. It can also use free dihydrolipoate, dihydrolipoamide or dihydrolipoyllysine as substrate. This enzyme was first shown to catalyse the oxidation of NADH by methylene blue; this activity was called diaphorase. The glycine cleavage system is composed of four components that only loosely associate: the P protein (EC 1.4.4.2), the T protein (EC 2.1.2.10), the L protein (EC 1.8.1.4) and the lipoyl-bearing H protein [6]

Links to other databases: BRENDA, EXPASY, KEGG, Metacyc, PDB, CAS registry number: 9001-18-7

References:

1. Massey, V. Lipoyl dehydrogenase. In: Boyer, P.D., Lardy, H. and MyrbÌÛck, K. (Eds), The Enzymes, 2nd edn, vol. 7, Academic Press, New York, 1963, pp. 275-306.

2. Massey, V., Gibson, Q.H. and Veeger, C. Intermediates in the catalytic action of lipoyl dehydrogenase (diaphorase). Biochem. J. 77 (1960) 341-351. [PMID: 13767908]

3. Savage, N. Preparation and properties of highly purified diaphorase. Biochem. J. 67 (1957) 146-155. [PMID: 13471525]

4. Straub, F.B. Isolation and properties of a flavoprotein from heart muscle tissue. Biochem. J. 33 (1939) 787-792.

5. Perham, R.N. Swinging arms and swinging domains in multifunctional enzymes: catalytic machines for multistep reactions. Annu. Rev. Biochem. 69 (2000) 961-1004. [PMID: 10966480]

6. Nesbitt, N.M., Baleanu-Gogonea, C., Cicchillo, R.M., Goodson, K., Iwig, D.F., Broadwater, J.A., Haas, J.A., Fox, B.G. and Booker, S.J. Expression, purification, and physical characterization of Escherichia coli lipoyl(octanoyl)transferase. Protein Expr. Purif. 39 (2005) 269-282. [PMID: 15642479]

[EC 1.8.1.4 created 1961 as EC 1.6.4.3, modified 1976, transferred 1983 to EC 1.8.1.4, modified 2003, modified 2006]

EC 1.8.1.5

Accepted name: 2-oxopropyl-CoM reductase (carboxylating)

Reaction: 2-mercaptoethanesulfonate + acetoacetate + NADP+ = 2-(2-oxopropylthio)ethanesulfonate + CO2 + NADPH

For diagram click here.

Glossary:
coenzyme M (CoM) = 2-sulfanylethane-1-sulfonate = 2-mercaptoethanesulfonate (deprecated)

Other name(s): NADPH:2-(2-ketopropylthio)ethanesulfonate oxidoreductase/carboxylase; NADPH:2-ketopropyl-coenzyme M oxidoreductase/carboxylase

Systematic name: 2-mercaptoethanesulfonate,acetoacetate:NADP+ oxidoreductase (decarboxylating)

Comments: Also acts on thioethers longer in chain length on the oxo side, e.g. 2-oxobutyl-CoM, but this portion must be attached to CoM (2-mercaptoethanesulfonate); no CoM analogs will substitute. This enzyme forms component II of a four-component enzyme system {comprising EC 4.4.1.23 (2-hydroxypropyl-CoM lyase; component I), EC 1.8.1.5 [2-oxopropyl-CoM reductase (carboxylating); component II], EC 1.1.1.268 [2-(R)-hydroxypropyl-CoM dehydrogenase; component III] and EC 1.1.1.269 [2-(S)-hydroxypropyl-CoM dehydrogenase; component IV]} that is involved in epoxyalkane carboxylation in Xanthobacter sp. strain Py2.

Links to other databases: BRENDA, EAWAG-BBD, EXPASY, KEGG, Metacyc, PDB, CAS registry number: 244301-63-1

References:

1. Allen, J.R., Clark, D.D., Krum, J.G. and Ensign, S.A. A role for coenzyme M (2-mercaptoethanesulfonic acid) in a bacterial pathway of aliphatic epoxide carboxylation. Proc. Natl. Acad. Sci. USA 96 (1999) 8432-8437. [PMID: 10411892]

2. Clark, D.D., Allen, J.R. and Ensign, S.A. Characterization of five catalytic activities associated with the NADPH:2-ketopropyl-coenzyme M [2-(2-ketopropylthio)ethanesulfonate] oxidoreductase/carboxylase of the Xanthobacter strain Py2 epoxide carboxylase system. Biochemistry 39 (2000) 1294-1304. [PMID: 10684609]

[EC 1.8.1.5 created 2001]

EC 1.8.1.6

Accepted name: cystine reductase

Reaction: 2 L-cysteine + NAD+ = L-cystine + NADH + H+

Other name(s): cystine reductase (NADH); NADH-dependent cystine reductase; cystine reductase (NADH2); NADH2:L-cystine oxidoreductase

Systematic name: L-cysteine:NAD+ oxidoreductase

Links to other databases: BRENDA, EXPASY, KEGG, Metacyc, CAS registry number: 9029-18-9

References:

1. Romano, A.H. and Nickerson, W.J. Cystine reductase of pea seeds and yeast. J. Biol. Chem. 208 (1954) 409-416.

2. Carroll, J.E., Kosicki, G.W. and Thibert, R.J. α-Substituted cystines as possible substrates for cystine reductase and L-amino acid oxidase. Biochim. Biophys. Acta 198 (1970) 601-603. [PMID: 5436160]

3. Maresca, B., Jacobson, E., Medoff, G. and Kobayashi, G. Cystine reductase in the dimorphic fungus Histoplasma capsulatum. J. Bacteriol. 135 (1978) 987-992. [PMID: 211119]

[EC 1.8.1.6 created 1961 as EC 1.6.4.1, transferred 2002 to EC 1.8.1.6]

EC 1.8.1.7

Accepted name: glutathione-disulfide reductase

Reaction: 2 glutathione + NADP+ = glutathione disulfide + NADPH + H+

For diagram of reaction click here.

Glossary:
The term 'oxidized glutathione' has been replaced by the term 'glutathione disulfide' as the former is ambiguous. S,S'-Biglutathione may also be used to refer to this compound.

Other name(s): glutathione reductase; glutathione reductase (NADPH); NADPH-glutathione reductase; GSH reductase; GSSG reductase; NADPH-GSSG reductase; glutathione S-reductase; NADPH:oxidized-glutathione oxidoreductase

Systematic name: glutathione:NADP+ oxidoreductase

Comments: A dimeric flavoprotein (FAD); activity is dependent on a redox-active disulfide in each of the active centres.

Links to other databases: BRENDA, EXPASY, GTD, KEGG, Metacyc, PDB, CAS registry number: 9001-48-3

References:

1. Pai, E.F., Schirmer, R.H. and Schulz, G.E. Structural studies on crystalline glutathione reductase from human erythrocytes. In: Singer, T.P. and Ondarza, R.N. (Eds.), Mechanisms of Oxidizing Enzymes, Elsevier North Holland, New York, 1978, p. 17-22.

2. Pigiet, V.P. and Conley, R.R. Purification of thioredoxin, thioredoxin reductase, and glutathione reductase by affinity chromatography. J. Biol. Chem. 252 (1977) 6367-6372. [PMID: 330529]

3. Racker, E. Glutathione reductase from bakers' yeast and beef liver. J. Biol. Chem. 217 (1955) 855-865.

4. van Heyningen, R. and Pirie, A. Reduction of glutathione coupled with oxidative decarboxylation of malate in cattle lens. Biochem. J. 53 (1953) 436-444.

5. Worthington, D.J. and Rosemeyer, M.A. Glutathione reductase from human erythrocytes. Catalytic properties and aggregation. Eur. J. Biochem. 67 (1976) 231-238. [PMID: 9277]

6. Böhmé, C.C., Arscott, L.D., Becker, K., Schirmer, R.H. and Williams, C.H., Jr. Kinetic characterization of glutathione reductase from the malarial parasite Plasmodium falciparum. Comparison with the human enzyme. J. Biol. Chem. 275 (2000) 37317-37323. [PMID: 10969088]

7. Libreros-Minotta, C.A., Pardo, J.P., Mendoza-Hernandez, G. and Rendon, J.L. Purification and characterization of glutathione reductase from Rhodospirillum rubrum. Arch Biochem Biophys 298 (1992) 247-253. [PMID: 1524433]

[EC 1.8.1.7 created 1961 as EC 1.6.4.2, modified 1989, transferred 2002 to EC 1.8.1.7]

EC 1.8.1.8

Accepted name: protein-disulfide reductase

Reaction: protein-dithiol + NAD(P)+ = protein-disulfide + NAD(P)H + H+

Other name(s): protein disulphide reductase; insulin-glutathione transhydrogenase; disulfide reductase; NAD(P)H2:protein-disulfide oxidoreductase

Systematic name: protein-dithiol:NAD(P)+ oxidoreductase

Links to other databases: BRENDA, EXPASY, KEGG, Metacyc, PDB, CAS registry number: 9029-19-0

References:

1. Hatch, M.D. and Turner, J.F. A protein disulphide reductase from pea seeds. Biochem. J. 76 (1960) 556-562.

[EC 1.8.1.8 created 1965 as EC 1.6.4.4, transferred 2002 to EC 1.8.1.8]

EC 1.8.1.9

Accepted name: thioredoxin-disulfide reductase

Reaction: thioredoxin + NADP+ = thioredoxin disulfide + NADPH + H+

Glossary: The term 'oxidized thioredoxin' has been replaced by 'thioredoxin disulfide' as the former is ambiguous.

Other name(s): NADP-thioredoxin reductase; NADPH-thioredoxin reductase; thioredoxin reductase (NADPH); NADPH2:oxidized thioredoxin oxidoreductase

Systematic name: thioredoxin:NADP+ oxidoreductase

Comments: A flavoprotein (FAD).

Links to other databases: BRENDA, EXPASY, GTD, KEGG, Metacyc, PDB, CAS registry number: 9074-14-0

References:

1. Moore, E.C., Reichard, P. and Thelander, L. Enzymatic synthesis of deoxyribonucleotides. V. Purification and properties of thioredoxin reductase from Escherichia coli B. J. Biol. Chem. 239 (1964) 3445-3452.

2. Speranza, M.L., Ronchi, S. and Minchiotti, L. Purification and characterization of yeast thioredoxin reductase. Biochim. Biophys. Acta 327 (1973) 274-281. [PMID: 4149839]

3. Arner, E.S. and Holmgren, A. Physiological functions of thioredoxin and thioredoxin reductase. Eur. J. Biochem. 267 (2000) 6102-6109. [PMID: 11012661]

[EC 1.8.1.9 created 1972 as EC 1.6.4.5, transferred 2002 to EC 1.8.1.9]

EC 1.8.1.10

Accepted name: CoA-glutathione reductase

Reaction: CoA + glutathione + NADP+ = CoA-glutathione + NADPH + H+

Other name(s): coenzyme A glutathione disulfide reductase; NADPH-dependent coenzyme A-SS-glutathione reductase; coenzyme A disulfide-glutathione reductase; NADPH2:CoA-glutathione oxidoreductase

Systematic name: glutathione:NADP+ oxidoreductase (CoA-acylating)

Comments: A flavoprotein. The substrate is a mixed disulfide. May be identical to EC 1.8.1.9, thioredoxin-disulfide reductase.

Links to other databases: BRENDA, EXPASY, KEGG, Metacyc, CAS registry number: 37256-33-0

References:

1. Ondarza, R.N., Abney, R. and López-Colomé, A.M. Characterization of a NADPH-dependent coenzyme A-SS-glutathione reductase from yeast. Biochim. Biophys. Acta 191 (1969) 239-248. [PMID: 4390951]

2. Ondarza, R.N., Escamilla, E., Gutierrez, J. and De la Chica, G. CoAS-Sglutathione and GSSG reductases from rat liver. Two disulfide oxidoreductase activities in one protein entity. Biochim. Biophys. Acta 341 (1974) 162-171. [PMID: 4151341]

3. Carlberg, I. and Mannervik, B. Purification by affinity chromatography of yeast glutathione reductase, the enzyme responsible for the NADPH-dependent reduction of the mixed disulfide of coenzyme A and glutathione. Biochim. Biophys. Acta 484 (1977) 268-274. [PMID: 334266]

[EC 1.8.1.10 created 1972 as EC 1.6.4.6, transferred 2002 to EC 1.8.1.10]

EC 1.8.1.11

Accepted name: asparagusate reductase

Reaction: 3-sulfanyl-2-(sulfanylmethyl)propanoat + NAD+ = asparagusate + NADH + H+

For diagram click here.

Glossary: 3-sulfanyl-2-(sulfanylmethyl)propanoate = 3-mercapto-2-mercaptomethylpropanoate (deprecated)
asparagusate = 1,2-dithiolane-4-carboxylate

Other name(s): asparagusate dehydrogenase; asparagusic dehydrogenase; asparagusate reductase (NADH2); NADH2:asparagusate oxidoreductase

Systematic name: 3-mercapto-2-mercaptomethylpropanoate:NAD+ oxidoreductase

Comments: Also acts on lipoate.

Links to other databases: BRENDA, EXPASY, KEGG, Metacyc, CAS registry number: 56126-52-4

References:

1. Yanagawa, H. and Egami, F. Asparagusate dehydrogenases and lipoyl dehydrogenase from asparagus mitochondria. Biochim. Biophys. Acta 384 (1975) 342-352. [PMID: 1125255]

2. Yanagawa, H. and Egami, F. Asparagusate dehydrogenases and lipoyl dehydrogenase from asparagus mitochondria. Physical, chemical, and enzymatic properties. J. Biol. Chem. 251 (1976) 3637-3644. [PMID: 180003]

[EC 1.8.1.11 created 1978 as EC 1.6.4.7, transferred 2002 to EC 1.8.1.11]

EC 1.8.1.12

Accepted name: trypanothione-disulfide reductase

Reaction: trypanothione + NADP+ = trypanothione disulfide + NADPH + H+

For diagram click here.

Glossary: spermidine

Other name(s): trypanothione reductase; NADPH2:trypanothione oxidoreductase

Systematic name: trypanothione:NADP+ oxidoreductase

Comments: Trypanothione disulfide is the oxidized form of N1,N8-bis(glutathionyl)-spermidine from the insect-parasitic trypanosomatid Crithidia fasciculata. The enzyme from Crithidia fasciculata is a flavoprotein (FAD), whose activity is dependent on a redox-active cystine at the active centre. (cf. EC 1.8.1.7, glutathione-disulfide reductase)

Links to other databases: BRENDA, EXPASY, KEGG, Metacyc, PDB, CAS registry number: 102210-35-5

References:

1. Shames, S.L., Fairlamb, A.H., Cerami, A. and Walsh, C.T. Purification and characterization of trypanothione reductase from Crithidia fasciculata, a newly discovered member of the family of disulfide-containing flavoprotein reductases. Biochemistry 25 (1986) 3519-3526.

2. Marsh, I.R. and Bradley, M. Substrate specificity of trypanothione reductase. Eur. J. Biochem. 243 (1977) 690-694. [PMID: 9057833]

3. Cunningham, M.L. and Fairlamb, A.H. Trypanothione reductase from Leishmania donovani. Purification, characterisation and inhibition by trivalent antimonials. Eur. J. Biochem. 230 (1995) 460-468. [PMID: 7607216]

[EC 1.8.1.12 created 1989 as EC 1.6.4.8, transferred 2002 to EC 1.8.1.12]

EC 1.8.1.13

Accepted name: bis-γ-glutamylcystine reductase

Reaction: 2 γ-glutamylcysteine + NADP+ = bis-γ-glutamylcystine + NADPH + H+

Other name(s): NADPH2:bis-γ-glutamylcysteine oxidoreductase

Systematic name: γ-glutamylcysteine:NADP+ oxidoreductase

Comments:Contains FAD. The enzyme, which is found only in halobacteria, maintains the concentration of γ-glutamylcysteine, the major low molecular weight thiol in halobacteria. Not identical with EC 1.8.1.7 (glutathione-disulfide reductase) or EC 1.8.1.14 (CoA-disulfide reductase).

Links to other databases: BRENDA, EXPASY, KEGG, Metacyc, CAS registry number: 117056-54-9

References:

1. Sundquist, A.R. and Fahey, R.C. The novel disulfide reductase bis-γ-glutamylcystine reductase and dihydrolipoamide dehydrogenase from Halobacterium halobium: purification by immobilized-metal-ion affinity chromatography and properties of the enzymes. J. Bacteriol. 170 (1988) 3459-3467. [PMID: 3136140]

2. Sundquist, A.R. and Fahey, R.C. The function of γ-glutamylcysteine and bis-γ-glutamylcystine reductase in Halobacterium halobium. J. Biol. Chem. 264 (1989) 719-725. [PMID: 2910862]

3. Kim, J. and Copley, S.D. The orphan protein bis-γ-glutamylcystine reductase joins the pyridine nucleotide-disulfide reductase family. Biochemistry 52 (2013) 2905-2913. [PMID: 23560638]

[EC 1.8.1.13 created 1992 as EC 1.6.4.9, transferred 2002 to EC 1.8.1.13]

EC 1.8.1.14

Accepted name: CoA-disulfide reductase

Reaction: 2 CoA + NADP+ = CoA-disulfide + NADPH + H+

Other name(s): CoA-disulfide reductase (NADH2); NADH2:CoA-disulfide oxidoreductase; CoA:NAD+ oxidoreductase (misleading); CoADR; coenzyme A disulfide reductase

Systematic name: CoA:NADP+ oxidoreductase

Comments: A flavoprotein. Not identical with EC 1.8.1.6 (cystine reductase), EC 1.8.1.7 (glutathione-disulfide reductase) or EC 1.8.1.13 (bis-γ-glutamylcystine reductase). The enzyme from the bacterium Staphylococcus aureus has a strong preference for NADPH [3], while the bacterium Bacillus megaterium contains both NADH and NADPH-dependent enzymes [1].

Links to other databases: BRENDA, EXPASY, KEGG, PDB, Metacyc, CAS registry number: 206770-55-0

References:

1. Setlow, B. and Setlow, P. Levels of acetyl coenzyme A, reduced and oxidized coenzyme A, and coenzyme A in disulfide linkage to protein in dormant and germinated spores and growing and sporulating cells of Bacillus megaterium. J. Bacteriol. 132 (1977) 444-452. [PMID: 410791]

2. delCardayré, S.B., Stock, K.P., Newton, G.L., Fahey, R.C. and Davies, J.E. Coenzyme A disulfide reductase, the primary low molecular weight disulfide reductase from Staphylococcus aureus. Purification and characterization of the native enzyme. J. Biol. Chem. 273 (1998) 5744-5751. [PMID: 9488707]

3. Luba, J., Charrier, V. and Claiborne, A. Coenzyme A-disulfide reductase from Staphylococcus aureus: evidence for asymmetric behavior on interaction with pyridine nucleotides. Biochemistry 38 (1999) 2725-2737. [PMID: 10052943]

[EC 1.8.1.14 created 1992 as EC 1.6.4.10, transferred 2002 to EC 1.8.1.14, modified 2005, modified 2013]

EC 1.8.1.15

Accepted name: mycothione reductase

Reaction: 2 mycothiol + NAD(P)+ = mycothione + NAD(P)H + H+

Glossary:
mycothiol = 1-O-[2-(N2-acetyl-L-cysteinamido)-2-deoxy-α-D-glucopyranosyl]-1D-myo-inositol
mycothione = oxidized (disulfide) form of mycothiol

Other name(s): mycothiol-disulfide reductase

Systematic name: mycothiol:NAD(P)+ oxidoreductase

Comments: Contains FAD. No activity with glutathione, trypanothione or coenzyme A as substrate.

Links to other databases: BRENDA, EXPASY, KEGG, Metacyc, CAS registry number: 252212-92-3

References:

1. Patel, M.P. and Blanchard, J.S. Expression, purification, and characterization of Mycobacterium tuberculosis mycothione reductase. Biochemistry 38 (1999) 11827-11833. [PMID: 10512639]

2. Patel, M.P. and Blanchard, J.S. Mycobacterium tuberculosis mycothione reductase: pH dependence of the kinetic parameters and kinetic isotope effects. Biochemistry 40 (2001) 5119-5126. [PMID: 11318633]

[EC 1.8.1.15 created 2002]

EC 1.8.1.16

Accepted name: glutathione amide reductase

Reaction: 2 glutathione amide + NAD+ = glutathione amide disulfide + NADH + H+

Other name(s): GAR

Systematic name: glutathione amide:NAD+ oxidoreductase

Comments: A dimeric flavoprotein (FAD). The enzyme restores glutathione amide disulfide, which is produced during the reduction of peroxide by EC 1.11.1.17 (glutathione amide-dependent peroxidase), back to glutathione amide (it catalyses the reaction in the opposite direction to that shown). The enzyme belongs to the family of flavoprotein disulfide oxidoreductases, but unlike other members of the family, which are specific for NADPH, it prefers NADH [1].

Links to other databases: BRENDA, EXPASY, KEGG, Metacyc, PDB, CAS registry number:

References:

1. Vergauwen, B., Pauwels, F., Jacquemotte, F., Meyer, T.E., Cusanovich, M.A., Bartsch, R.G. and Van Beeumen, J.J. Characterization of glutathione amide reductase from Chromatium gracile. Identification of a novel thiol peroxidase (Prx/Grx) fueled by glutathione amide redox cycling. J. Biol. Chem. 276 (2001) 20890-20897. [PMID: 11399772]

2. Vergauwen, B., Van Petegem, F., Remaut, H., Pauwels, F. and Van Beeumen, J.J. Crystallization and preliminary X-ray crystallographic analysis of glutathione amide reductase from Chromatium gracile. Acta Crystallogr. D Biol. Crystallogr. 58 (2002) 339-340. [PMID: 11807270]

[EC 1.8.1.16 created 2010]

EC 1.8.1.17

Accepted name: dimethylsulfone reductase

Reaction: dimethyl sulfoxide + H2O + NAD+ = dimethyl sulfone + NADH + H+

For diagram of reaction click here.

Comments: A molybdoprotein.

Links to other databases: BRENDA, EXPASY, KEGG, Metacyc, CAS registry number:

References:

1. Borodina, E., Kelly, D.P., Rainey, F.A., Ward-Rainey, N.L. and Wood, A.P. Dimethylsulfone as a growth substrate for novel methylotrophic species of Hyphomicrobium and Arthrobacter. Arch. Microbiol. 173 (2000) 425-437. [PMID: 10896224]

2. Borodina, E., Kelly, D.P., Schumann, P., Rainey, F.A., Ward-Rainey, N.L. and Wood, A.P. Enzymes of dimethylsulfone metabolism and the phylogenetic characterization of the facultative methylotrophs Arthrobacter sulfonivorans sp. nov., Arthrobacter methylotrophus sp. nov., and Hyphomicrobium sulfonivorans sp. nov. Arch. Microbiol. 177 (2002) 173-183. [PMID: 11807567]

[EC 1.8.1.17 created 2011]

EC 1.8.1.18

Accepted name: NAD(P)H sulfur oxidoreductase (CoA-dependent)

Reaction: hydrogen sulfide + NAD(P)+ = sulfur + NAD(P)H + H+

Other name(s): NADPH NSR; S0 reductase; coenzyme A-dependent NADPH sulfur oxidoreductase

Systematic name: hydrogen sulfide:NAD(P)+ oxidoreductase (CoA-dependent)

Comments: This FAD-dependent enzyme, characterized from the archaeon Pyrococcus furiosus, is responsible for NAD(P)H-linked sulfur reduction. The activity with NADH is about half of that with NADPH. The reaction is dependent on CoA, although the nature of this dependency is not well understood.

Links to other databases: BRENDA, EXPASY, KEGG Metacyc, CAS registry number:

References:

1. Schut, G.J., Bridger, S.L. and Adams, M.W. Insights into the metabolism of elemental sulfur by the hyperthermophilic archaeon Pyrococcus furiosus: characterization of a coenzyme A- dependent NAD(P)H sulfur oxidoreductase. J. Bacteriol. 189 (2007) 4431-4441. [PMID: 17449625]

2. Bridger, S.L., Clarkson, S.M., Stirrett, K., DeBarry, M.B., Lipscomb, G.L., Schut, G.J., Westpheling, J., Scott, R.A. and Adams, M.W. Deletion strains reveal metabolic roles for key elemental sulfur-responsive proteins in Pyrococcus furiosus. J. Bacteriol. 193 (2011) 6498-6504. [PMID: 21965560]

[EC 1.8.1.18 created 2013]

EC 1.8.1.19

Accepted name: sulfide dehydrogenase

Reaction: hydrogen sulfide + (sulfide)n + NADP+ = (sulfide)n+1 + NADPH + H+

Other name(s): SuDH

Systematic name: hydrogen sulfide,polysulfide:NADP+ oxidoreductase

Comments: A iron-sulfur flavoprotein. In the archaeon Pyrococcus furiosus the enzyme is involved in the oxidation of NADPH which is produced in peptide degradation. The enzyme also catalyses the reduction of sulfur with lower activity.

Links to other databases: BRENDA, EXPASY, KEGG, Metacyc, PDB, CAS registry number:

References:

1. Ma, K. and Adams, M.W. Sulfide dehydrogenase from the hyperthermophilic archaeon Pyrococcus furiosus: a new multifunctional enzyme involved in the reduction of elemental sulfur. J. Bacteriol. 176 (1994) 6509-6517. [PMID: 7961401]

2. Hagen, W.R., Silva, P.J., Amorim, M.A., Hagedoorn, P.L., Wassink, H., Haaker, H. and Robb, F.T. Novel structure and redox chemistry of the prosthetic groups of the iron-sulfur flavoprotein sulfide dehydrogenase from Pyrococcus furiosus; evidence for a [2Fe-2S] cluster with Asp(Cys)3 ligands. J. Biol. Inorg. Chem. 5 (2000) 527-534. [PMID: 10968624]

[EC 1.8.1.19 created 2013]

EC 1.8.1.20

Accepted name: 4,4'-dithiodibutanoate disulfide reductase

Reaction: 2 4-sulfanylbutanoate + NAD+ = 4,4'-disulfanediyldibutanoate + NADH + H+

Systematic name: 4-sulfanylbutanoate:NAD+ oxidoreductase

Comments: The enzyme, characterized from the bacterium Rhodococcus erythropolis MI2, contains an FMN cofator.

Links to other databases: BRENDA, EXPASY, KEGG, MetaCyc, CAS registry number:

References:

1. Khairy, H., Wubbeler, J.H. and Steinbuchel, A. Biodegradation of the organic disulfide 4,4'-dithiodibutyric acid by Rhodococcus spp. Appl. Environ. Microbiol. 81 (2015) 8294-8306. [PMID: 26407888]

2. Khairy, H., Wubbeler, J.H. and Steinbuchel, A. The NADH:flavin oxidoreductase Nox from Rhodococcus erythropolis MI2 is the key enzyme of 4,4'-dithiodibutyric acid degradation. Lett. Appl. Microbiol. 63 (2016) 434-441. [PMID: 27564089]

[EC 1.8.1.20 created 2017]

EC 1.8.1.21

Accepted name: dissimilatory dimethyldisulfide reductase

Reaction: 2 methanethiol + NAD+ = dimethyl disulfide + NADH + H+

Systematic name: methanethiol:NAD+ oxidoreductase (dimethyl disulfide-forming)

Comments: The enzyme's activity has been demonstrated in the bacterium Thiobacillus thioparus E6. The methanethiol formed is eventually oxidized to sulfate and carbon dioxide, and the latter assimilated for autotrophic growth.

Links to other databases: BRENDA, EXPASY, KEGG, MetaCyc, CAS registry number:

References:

1. Smith, N. A. and Kelly, D. P. Isolation and physiological characterization of authotrophic sulphur bacteria oxidizing dimethyldisulphide as sole source of energy. J. Gen. Microbiol. 134 (1988) 1407-1417.

2. Smith, N. A. and Kelly, D. P. Mechanism of oxidation of dimethyl disulphide by Thiobacillus thioparus E6. J. Gen. Microbiol. 134 (1988) 3031-3039.

[EC 1.8.1.21 created 2019]

EC 1.8.1.22

Accepted name: dissimilatory sulfite reductase system

Reaction: a [DsrC protein]-trisulfide + NAD+ + 3 H2O = a [DsrC protein]-dithiol + sulfite + NADH + H+

Other name(s): siroheme sulfite reductase; DsrABL; hydrogen-sulfide:(acceptor) oxidoreductase (incorrect)

Systematic name: [DsrC protein]-trisulfide,NAD+ oxidoreductase (sulfite-forming)

Comments: Contains siroheme. The enzyme is essential in prokaryotic sulfur-based energy metabolism, including sulfate/sulfite reducing organisms, sulfur-oxidizing bacteria, and organosulfonate reducers. The system comprises the DsrAB reductase and the DsrL protein, which form a tight complex. The reaction involves the small protein DsrC, which is present in all the organisms that contain dissimilatory sulfite reductase. In sulfite reducers the DsrL component transfers two electrons from NADH to the DsrAB component, which then reduces the sulfur in sulfite to an S(II) intermediate that forms (together with two cysteine residues of DsrC) a trisulfide. In sulfur oxidizers the enzyme catalyses the opposite reaction [1].

Links to other databases: BRENDA, EXPASY, KEGG, MetaCyc, CAS registry number:

References:

1. Schedel, M., Vanselow, M. and Trueper, H. G. Siroheme sulfite reductase from Chromatium vinosum. Purification and investigation of some of its molecular and catalytic properties. Arch. Microbiol. 121 (1979) 29-36.

2. Seki, Y., Sogawa, N. and Ishimoto, M. Siroheme as an active catalyst in sulfite reduction. J. Biochem. 90 (1981) 1487-1492. [PMID: 7338517]

3. Pott, A.S. and Dahl, C. Sirohaem sulfite reductase and other proteins encoded by genes at the dsr locus of Chromatium vinosum are involved in the oxidation of intracellular sulfur. Microbiology (Reading) 144 (1998) 1881-1894. [PMID: 9695921]

4. Oliveira, T.F., Vonrhein, C., Matias, P.M., Venceslau, S.S., Pereira, I.A. and Archer, M. The crystal structure of Desulfovibrio vulgaris dissimilatory sulfite reductase bound to DsrC provides novel insights into the mechanism of sulfate respiration. J. Biol. Chem. 283 (2008) 34141-34149. [PMID: 18829451]

5. Venceslau, S.S., Stockdreher, Y., Dahl, C. and Pereira, I.A. The "bacterial heterodisulfide" DsrC is a key protein in dissimilatory sulfur metabolism. Biochim. Biophys. Acta 1837 (2014) 1148-1164. [PMID: 24662917]

6. Loffler, M., Feldhues, J., Venceslau, S.S., Kammler, L., Grein, F., Pereira, I.AC. and Dahl, C. DsrL mediates electron transfer between NADH and rDsrAB in Allochromatium vinosum. Environ. Microbiol. 22 (2020) 783-795. [PMID: 31854015]

[EC 1.8.1.22 created 2015 as EC 1.8.99.5, transferred 2023 to EC 1.8.1.22 ]


EC 1.8.2 With a cytochrome as acceptor

Contents

EC 1.8.2.1 sulfite dehydrogenase (cytochrome)
EC 1.8.2.2 thiosulfate dehydrogenase
EC 1.8.2.3 sulfide-cytochrome-c reductase (flavocytochrome c)
EC 1.8.2.4 dimethyl sulfide:cytochrome c2 reductase
EC 1.8.2.5 thiosulfate reductase (cytochrome)
EC 1.8.2.6 S-disulfanyl-L-cysteine oxidoreductase
EC 1.8.2.7 thiocyanate desulfurase

EC 1.8.2.1

Accepted name: sulfite dehydrogenase (cytochrome)

Reaction: sulfite + 2 ferricytochrome c + H2O = sulfate + 2 ferrocytochrome c + 2 H+

Other name(s): sulfite cytochrome c reductase; sulfite-cytochrome c oxidoreductase; sulfite oxidase (ambiguous); sulfite dehydrogenase (ambiguous); sorAB (gene names)

Systematic name: sulfite:ferricytochrome-c oxidoreductase

Comments: Associated with cytochrome c-551. The enzyme from the bacterium Starkeya novella contains a molybdopyranopterin cofactor and a smaller monoheme cytochrome c subunit. cf. EC 1.8.5.6, sulfite dehydrogenase (quinone).

Links to other databases: BRENDA, EXPASY, KEGG, MetaCyc, PDB, CAS registry number: 37256-47-6

References:

1. Charles, A.M. and Suzuki, I. Purification and properties of sulfite:cytochrome c oxidoreductase from Thiobacillus novellus. Biochim. Biophys. Acta 128 (1966) 522-534.

2. Lyric, R.M. and Suzuki, I. Enzymes involved in the metabolism of thiosulfate by Thiobacillus thioparus. I. Survey of enzymes and properties of sulfite: cytochrome c oxidoreductase. Can. J. Biochem. 48 (1970) 334-343. [PMID: 5438321]

3. Yamanaka, T., Yoshioka, T. and Kimura, K. Purification of sulphite cytocrome c reductase of Thiobacillus novellus and reconstitution of its sulphite oxidase system with the purified constituents. Plant and Cell Physiol. 22 (1981) 631.

4. Lu, W.-P. and Kelly, D.P. Properties and role of sulphite:cytochrome c oxidoreductase purified from Thiobacillus versutus (A2). J. Gen. Microbiol. 130 (1984) 1683-1692.

5. Kappler, U., Bennett, B., Rethmeier, J., Schwarz, G., Deutzmann, R., McEwan, A.G. and Dahl, C. Sulfite:Cytochrome c oxidoreductase from Thiobacillus novellus. Purification, characterization, and molecular biology of a heterodimeric member of the sulfite oxidase family. J. Biol. Chem. 275 (2000) 13202-13212. [PMID: 10788424]

[EC 1.8.2.1 created 1972, modified 2016]

EC 1.8.2.2

Accepted name: thiosulfate dehydrogenase

Reaction: 2 thiosulfate + 2 ferricytochrome c = tetrathionate + 2 ferrocytochrome c

Other name(s): tsdA (gene name); tetrathionate synthase; thiosulfate oxidase; thiosulfate-oxidizing enzyme; thiosulfate-acceptor oxidoreductase

Systematic name: thiosulfate:ferricytochrome-c oxidoreductase

Comments: The enzyme catalyses the reversible formation of a sulfur-sulfur bond between the sulfane atoms of two thiosulfate molecules, yielding tetrathionate and releasing two electrons. In many bacterial species the enzyme is a diheme c-type cytochrome. In a number of organisms, including Thiomonas intermedia and Sideroxydans lithotrophicus, a second diheme cytochrome (TsdB) acts as the electron acceptor. However, some organisms, such as Allochromatium vinosum, lack TsdB. The electron acceptor in these organisms may be the high-potential iron-sulfur protein (HiPIP).

Links to other databases: BRENDA, EXPASY, KEGG, Metacyc, PDB, CAS registry number: 9076-88-4

References:

1. Fukumori, Y. and Yamanaka, T. A high-potential nonheme iron protein (HiPIP)-linked, thiosulfate-oxidizing enzyme derived from Chromatium vinosum. Curr. Microbiol. 3 (1979) 117-120.

2. Lu, W.-P. and Kelly, D.P. Cellular location and partial purification of the 'thiosulphate-oxidizing enzyme' and 'trithionate hydrolase' from Thiobacillus tepidarius. J. Gen. Microbiol. 134 (1988) 877-885.

3. Liu, Y.W., Denkmann, K., Kosciow, K., Dahl, C. and Kelly, D.J. Tetrathionate stimulated growth of Campylobacter jejuni identifies a new type of bi-functional tetrathionate reductase (TsdA) that is widely distributed in bacteria. Mol. Microbiol. 88 (2013) 173-188. [PMID: 23421726]

4. Brito, J.A., Denkmann, K., Pereira, I.A., Archer, M. and Dahl, C. Thiosulfate dehydrogenase (TsdA) from Allochromatium vinosum: structural and functional insights into thiosulfate oxidation. J. Biol. Chem. 290 (2015) 9222-9238. [PMID: 25673691]

5. Kurth, J.M., Brito, J.A., Reuter, J., Flegler, A., Koch, T., Franke, T., Klein, E.M., Rowe, S.F., Butt, J.N., Denkmann, K., Pereira, I.A., Archer, M. and Dahl, C. Electron accepting units of the diheme cytochrome c TsdA, a bifunctional thiosulfate dehydrogenase/tetrathionate reductase. J. Biol. Chem. 291 (2016) 24804-24818. [PMID: 27694441]

[EC 1.8.2.2 created 1990]

EC 1.8.2.3

Accepted name: sulfide-cytochrome-c reductase (flavocytochrome c)

Reaction: hydrogen sulfide + 2 ferricytochrome c = sulfur + 2 ferrocytochrome c + 2 H+

Systematic name: hydrogen-sulfide:flavocytochrome c oxidoreductase

Comments: The enzyme from Allochromatium vinosum contains covalently bound FAD and covalently-bound c-type hemes.

Links to other databases: BRENDA, EXPASY, KEGG, Metacyc, PDB, CAS registry number:

References:

1. Kusai, K. and Yamanaka, T. The oxidation mechanisms of thiosulphate and sulphide in Chlorobium thiosulphatophilum: roles of cytochrome c-551 and cytochrome c-553. Biochim. Biophys. Acta 325 (1973) 304-314. [PMID: 4357558]

2. Fukumori, Y. and Yamanaka, T. Flavocytochrome c of Chromatium vinosum. Some enzymatic properties and subunit structure. J. Biochem. 85 (1979) 1405-1414. [PMID: 222744]

3. Gray, G.O., Gaul, D.F. and Knaff, D.B. Partial purification and characterization of two soluble c-type cytochromes from Chromatium vinosum. Arch. Biochem. Biophys. 222 (1983) 78-86. [PMID: 6301383]

4. Chen, Z.W., Koh, M., Van Driessche, G., Van Beeumen, J.J., Bartsch, R.G., Meyer, T.E., Cusanovich, M.A. and Mathews, F.S. The structure of flavocytochrome c sulfide dehydrogenase from a purple phototrophic bacterium. Science 266 (1994) 430-432. [PMID: 7939681]

5. Sorokin, D.Yu, de Jong, G.A., Robertson, L.A. and Kuenen, G.J. Purification and characterization of sulfide dehydrogenase from alkaliphilic chemolithoautotrophic sulfur-oxidizing bacteria. FEBS Lett. 427 (1998) 11-14. [PMID: 9613590]

6. Kostanjevecki, V., Brige, A., Meyer, T.E., Cusanovich, M.A., Guisez, Y. and van Beeumen, J. A membrane-bound flavocytochrome c-sulfide dehydrogenase from the purple phototrophic sulfur bacterium Ectothiorhodospira vacuolata. J. Bacteriol. 182 (2000) 3097-3103. [PMID: 10809687]

[EC 1.8.2.3 created 2011]

EC 1.8.2.4

Accepted name: dimethyl sulfide:cytochrome c2 reductase

Reaction: dimethyl sulfide + 2 ferricytochrome c2 + H2O = dimethyl sulfoxide + 2 ferrocytochrome c2 + 2 H+

For diagram of reaction click here.

Other name(s): Ddh (gene name)

Systematic name: dimethyl sulfide:ferricytochrome-c2 oxidoreductase

Comments: The enzyme from Rhodovulum sulfidophilum binds molybdopterin guanine dinucleotide, heme b and [4Fe-4S] clusters.

Links to other databases: BRENDA, EXPASY, KEGG, Metacyc, CAS registry number:

References:

1. Hanlon, S.P., Toh, T.H., Solomon, P.S., Holt, R.A. and McEwan, A.G. Dimethylsulfide:acceptor oxidoreductase from Rhodobacter sulfidophilus. The purified enzyme contains b-type haem and a pterin molybdenum cofactor. Eur. J. Biochem. 239 (1996) 391-396. [PMID: 8706745]

2. McDevitt, C.A., Hugenholtz, P., Hanson, G.R. and McEwan, A.G. Molecular analysis of dimethyl sulphide dehydrogenase from Rhodovulum sulfidophilum: its place in the dimethyl sulphoxide reductase family of microbial molybdopterin-containing enzymes. Mol. Microbiol. 44 (2002) 1575-1587. [PMID: 12067345]

[EC 1.8.2.4 created 2011]

EC 1.8.2.5

Accepted name: thiosulfate reductase (cytochrome)

Reaction: sulfite + hydrogen sulfide + 2 ferricytochrome c3 = thiosulfate + 2 ferrocytochrome c3

Systematic name: sulfite,hydrogen sulfide:ferricytochrome-c3 oxidoreductase (thiosulfate-forming)

Comments: The enzyme is found in sulfate-reducing bacteria. The source of the electrons is molecular hydrogen, via EC 1.12.2.1, cytochrome-c3 hydrogenase. The organisms utilize the sulfite that is produced for energy generation by EC 1.8.99.5, dissimilatory sulfite reductase.

Links to other databases: BRENDA, EXPASY, KEGG, MetaCyc, CAS registry number:

References:

1. Ishimoto, M. and Koyama, J. On the role of a cytochrome in the thiosulfate reduction by sulfate-reducing bacterium. B. Chem. Soc. Jpn. 28 (1955) 231b-232.

2. Ishimoto, M., Toyama, J. Biochemical studies on sulfate reducing bacteria. VI. Separation of hydrogenase and thiosulfate reductase and partial purification of cytochrome and green pigment. J. Biochem. (Tokyo) 44 (1957) 233-242.

3. Nakatsukasa, W. and Akagi, J.M. Thiosulfate reductase isolated from Desulfotomaculum nigrificans. J. Bacteriol. 98 (1969) 429-433. [PMID: 5784203]

4. Haschke, R.H. and Campbell, L.L. Thiosulfate reductase of Desulfovibrio vulgaris. J. Bacteriol. 106 (1971) 603-607. [PMID: 5573735]

5. Hatchikian, E.C. Purification and properties of thiosulfate reductase from Desulfovibrio gigas. Arch. Microbiol. 105 (1975) 249-256. [PMID: 242299]

6. Aketagawa, J., Kobayashi, K. and Ishimoto, M. Purification and properties of thiosulfate reductase from Desulfovibrio vulgaris, Miyazaki F. J. Biochem. 97 (1985) 1025-1032. [PMID: 2993256]

[EC 1.8.2.5 created 2017]

EC 1.8.2.6

Accepted name: S-disulfanyl-L-cysteine oxidoreductase

Reaction: [SoxY protein]-S-disulfanyl-L-cysteine + 6 ferricytochrome c + 3 H2O = [SoxY protein]-S-sulfosulfanyl-L-cysteine + 6 ferrocytochrome c + 6 H+

Other name(s): SoxCD; sulfur dehydrogenase

Systematic name: [SoxY protein]-S-disulfanyl-L-cysteine:cytochrome-c oxidoreductase

Comments: The enzyme is part of the Sox enzyme system, which participates in a bacterial thiosulfate oxidation pathway that produces sulfate. The enzyme from the bacterium Paracoccus pantotrophus contains a molybdoprotein component and a diheme c-type cytochrome component. The enzyme successively oxidizes the outer sulfur atom in [SoxY protein]-S-disulfanyl-L-cysteine, using three water molecules and forming [SoxY protein]-S-sulfosulfanyl-L-cysteine. During the process, six electrons are transferred to the electron chain via cytochrome c.

Links to other databases: BRENDA, EXPASY, KEGG, Metacyc, CAS registry number:

References:

1. Friedrich, C.G., Rother, D., Bardischewsky, F., Quentmeier, A. and Fischer, J. Oxidation of reduced inorganic sulfur compounds by bacteria: emergence of a common mechanism. Appl. Environ. Microbiol. 67 (2001) 2873-2882. [PMID: 11425697]

2. Bardischewsky, F., Quentmeier, A., Rother, D., Hellwig, P., Kostka, S. and Friedrich, C.G. Sulfur dehydrogenase of Paracoccus pantotrophus: the heme-2 domain of the molybdoprotein cytochrome c complex is dispensable for catalytic activity. Biochemistry 44 (2005) 7024-7034. [PMID: 15865447]

3. Grabarczyk, D.B. and Berks, B.C. Intermediates in the Sox sulfur oxidation pathway are bound to a sulfane conjugate of the carrier protein SoxYZ. PLoS One 12 (2017) e0173395. [PMID: 28257465]

[EC 1.8.2.6 created 2018]

EC 1.8.2.7

Accepted name: thiocyanate desulfurase

Reaction: thiocyanate + 2 ferricytochrome c + H2O = cyanate + sulfur + 2 ferrocytochrome c + 2 H+

Other name(s): TcDH; thiocyanate dehydrogenase

Systematic name: thiocyanate:cytochrome c oxidoreductase (cyanate and sulfur-forming)

Comments: The enzyme, characterized from the haloalkaliphilic sulfur-oxidizing bacterium Thioalkalivibrio paradoxus, contains three copper ions in its active site. It catalyses the direct conversion of thiocyanate into cyanate and elemental sulfur without involvement of molecular oxygen.

Links to other databases: BRENDA, EXPASY, KEGG, Metacyc, PDB, CAS registry number:

References:

1. Tikhonova, T.V., Sorokin, D.Y., Hagen, W.R., Khrenova, M.G., Muyzer, G., Rakitina, T.V., Shabalin, I.G., Trofimov, A.A., Tsallagov, S.I. and Popov, V.O. Trinuclear copper biocatalytic center forms an active site of thiocyanate dehydrogenase. Proc. Natl. Acad. Sci. USA (2020) . [PMID: 32094184]

[EC 1.8.2.7 created 2020]


EC 1.8.3 With oxygen as acceptor

Contents

EC 1.8.3.1 sulfite oxidase
EC 1.8.3.2 thiol oxidase
EC 1.8.3.3 glutathione oxidase
EC 1.8.3.4 methanethiol oxidase
EC 1.8.3.5 prenylcysteine oxidase
EC 1.8.3.6 farnesylcysteine lyase
EC 1.8.3.7 formylglycine-generating enzyme


EC 1.8.3.1

Accepted name: sulfite oxidase

Reaction: sulfite + O2 + H2O = sulfate + H2O2

Systematic name: sulfite:oxygen oxidoreductase

Comments: A molybdohemoprotein.

Links to other databases: BRENDA, EXPASY, KEGG, Metacyc, PDB, CAS registry number: 9029-38-3

References:

1. Kessel, D.L., Johnston, J.L., Cohen, H.J. and Rajagopalan, K.V. Visualization of hepatic sulfite oxidase in crude tissue preparation by electron paramagnetic resonance spectroscopy. Biochim. Biophys. Acta 334 (1974) 86-96.

2. MacLeod, R.M., Farkas, W., Fridovitch, I. and Handler, P. Purfication and properties of hepatic sulfite oxidase. J. Biol. Chem. 236 (1961) 1841-1846.

3. Tager, J.M. and Rautanen, N. Sulfite oxidation by a plant mitochondrial system. I. Preliminary observations. Biochim. Biophys. Acta 18 (1955) 111-121.

[EC 1.8.3.1 created 1961]

EC 1.8.3.2

Accepted name: thiol oxidase

Reaction: 2 R'C(R)SH + O2 = R'C(R)S-S(R)CR' + H2O2

Other name(s): sulfhydryl oxidase

Systematic name: thiol:oxygen oxidoreductase

Comments: R may be =S or =O, or a variety of other groups. The enzyme is not specific for R'.

Links to other databases: BRENDA, EAWAG-BBD, EXPASY, KEGG, Metacyc, PDB, CAS registry number: 9029-39-4

References:

1. Aurbach, G.D. and Jakoby, W.B. The multiple functions of thiooxidase. J. Biol. Chem. 237 (1962) 565-568. [PMID: 13863296]

2. Neufeld, H.A., Green, L.F., Latterell, F.M. and Weintraub, R.L. Thiooxidase, a new sulfhydryl-oxidizing enzyme from Piricularia oryzae and Polyporus vesicolor. J. Biol. Chem. 232 (1958) 1093-1099. [PMID: 13549489]

3. Ostrowski, M.C. and Kistler, W.S. Properties of a flavoprotein sulfhydryl oxidase from rat seminal vesicle secretion. Biochemistry 19 (1980) 2639-2645. [PMID: 7397095]

4. Hoober, K.L., Joneja, B., White, H.B., 3rd and Thorpe, C. A sulfhydryl oxidase from chicken egg white. J. Biol. Chem. 271 (1996) 30510-30516. [PMID: 8940019]

5. Jaje, J., Wolcott, H.N., Fadugba, O., Cripps, D., Yang, A.J., Mather, I.H. and Thorpe, C. A flavin-dependent sulfhydryl oxidase in bovine milk. Biochemistry 46 (2007) 13031-13040. [PMID: 17944490]

6. Sevier, C.S., Cuozzo, J.W., Vala, A., Aslund, F. and Kaiser, C.A. A flavoprotein oxidase defines a new endoplasmic reticulum pathway for biosynthetic disulphide bond formation. Nat. Cell Biol. 3 (2001) 874-882. [PMID: 11584268]

7. Dabir, D.V., Leverich, E.P., Kim, S.K., Tsai, F.D., Hirasawa, M., Knaff, D.B. and Koehler, C.M. A role for cytochrome c and cytochrome c peroxidase in electron shuttling from Erv1. EMBO J. 26 (2007) 4801-4811. [PMID: 17972915]

8. Farrell, S.R. and Thorpe, C. Augmenter of liver regeneration: a flavin-dependent sulfhydryl oxidase with cytochrome c reductase activity. Biochemistry 44 (2005) 1532-1541. [PMID: 15683237]

9. Gross, E., Sevier, C.S., Heldman, N., Vitu, E., Bentzur, M., Kaiser, C.A., Thorpe, C. and Fass, D. Generating disulfides enzymatically: reaction products and electron acceptors of the endoplasmic reticulum thiol oxidase Ero1p. Proc. Natl. Acad. Sci. USA 103 (2006) 299-304. [PMID: 16407158]

10. de la Motte, R.S. and Wagner, F.W. Aspergillus niger sulfhydryl oxidase. Biochemistry 26 (1987) 7363-7371. [PMID: 3427078]

11. Riemer, J., Bulleid, N. and Herrmann, J.M. Disulfide formation in the ER and mitochondria: two solutions to a common process. Science 324 (2009) 1284-1287. [PMID: 19498160]

[EC 1.8.3.2 created 1961, modified 2010, modified 2011]

EC 1.8.3.3

Accepted name: glutathione oxidase

Reaction: 2 glutathione + O2 = glutathione disulfide + H2O2

Systematic name: glutathione:oxygen oxidoreductase

Comments: A flavoprotein (FAD). Also acts, more slowly, on L-cysteine and several other thiols.

Links to other databases: BRENDA, EXPASY, KEGG, Metacyc, CAS registry number: 55467-56-6

References:

1. Kusakabe, H., Kuninaka, A. and Yoshino, H. Purification and properties of a new enzyme, glutathione oxidase from Penicillium sp.K-6-5. Agric. Biol. Chem. 46 (1982) 2057-2067.

[EC 1.8.3.3 created 1989]

EC 1.8.3.4

Accepted name: methanethiol oxidase

Reaction: methanethiol + O2 + H2O = formaldehyde + hydrogen sulfide + H2O2

Other name(s): methylmercaptan oxidase; methyl mercaptan oxidase; (MM)-oxidase; MT-oxidase

Systematic name: methanethiol:oxygen oxidoreductase

Links to other databases: BRENDA, EAWAG-BBD, EXPASY, KEGG, Metacyc, CAS registry number: 289686-00-6

References:

1. Suylen, G.M.H., Large, P.J., van Dijken, J.P. and Kuenen, J.G. Methylmercaptan oxidase, a key enzyme in the metabolism of methylated sulphur compounds by Hyphomicrobium EG. J. Gen. Microbiol. 133 (1987) 2989-2997.

[EC 1.8.3.4 created 1990]

EC 1.8.3.5

Accepted name: prenylcysteine oxidase

Reaction: an S-prenyl-L-cysteine + O2 + H2O = a prenal + L-cysteine + H2O2

Other name(s): prenylcysteine lyase

Systematic name: S-prenyl-L-cysteine:oxygen oxidoreductase

Comments: A flavoprotein (FAD). Cleaves the thioether bond of S-prenyl-L-cysteines, such as S-farnesylcysteine and S-geranylgeranylcysteine. N-Acetyl-prenylcysteine and prenylcysteinyl peptides are not substrates. May represent the final step in the degradation of prenylated proteins in mammalian tissues. Originally thought to be a simple lyase so it had been classified as EC 4.4.1.18.

Links to other databases: BRENDA, EXPASY, KEGG, Metacyc, CAS registry number:

References:

1. Zhang, L., Tschantz, W.R. and Casey, P.J. Isolation and characterization of a prenylcysteine lyase from bovine brain. J. Biol. Chem. 272 (1997) 23354-23359. [PMID: 9287348]

2. Tschantz, W.R., Digits, J.A., Pyun, H.J., Coates, R.M. and Casey, P.J. Lysosomal prenylcysteine lyase is a FAD-dependent thioether oxidase. J. Biol. Chem. 276 (2001) 2321-2324. [PMID: 11078725]

[EC 1.8.3.5 created 2000 as EC 4.4.1.18, transferred 2002 to EC 1.8.3.5]

EC 1.8.3.6

Accepted name: farnesylcysteine lyase

Reaction: S-(2E,6E)-farnesyl-L-cysteine + O2 + H2O = (2E,6E)-farnesal + L-cysteine + H2O2

Other name(s): FC lyase; FCLY

Systematic name: S-(2E,6E)-farnesyl-L-cysteine oxidase

Comments: A flavoprotein (FAD). In contrast to mammalian EC 1.8.3.5 (prenylcysteine oxidase) the farnesylcysteine lyase from Arabidopsis is specific for S-farnesyl-L-cysteine and shows no activity with S-geranylgeranyl-L-cysteine.

Links to other databases: BRENDA, EXPASY, KEGG, Metacyc, CAS registry number:

References:

1. Huizinga, D.H., Denton, R., Koehler, K.G., Tomasello, A., Wood, L., Sen, S.E. and Crowell, D.N. Farnesylcysteine lyase is involved in negative regulation of abscisic acid signaling in Arabidopsis. Mol Plant 3 (2010) 143-155. [PMID: 19969520]

2. Crowell, D.N., Huizinga, D.H., Deem, A.K., Trobaugh, C., Denton, R. and Sen, S.E. Arabidopsis thaliana plants possess a specific farnesylcysteine lyase that is involved in detoxification and recycling of farnesylcysteine. Plant J. 50 (2007) 839-847. [PMID: 17425716]

[EC 1.8.3.6 created 2011]

EC 1.8.3.7

Accepted name: formylglycine-generating enzyme

Reaction: a [sulfatase]-L-cysteine + O2 + 2 a thiol = a [sulfatase]-3-oxo-L-alanine + hydrogen sulfide + a disulfide + H2O

Glossary: 3-oxo-L-alanine = formylglycine = Cα-formylglycine = FGly

Other name(s): sulfatase-modifying factor 1; Cα-formylglycine-generating enzyme 1; SUMF1 (gene name)

Systematic name: [sulfatase]-L-cysteine:oxygen oxidoreductase (3-oxo-L-alanine-forming)

Comments: Requires a copper cofactor and Ca2+. The enzyme, which is found in both prokaryotes and eukaryotes, catalyses a modification of a conserved L-cysteine residue in the active site of sulfatases, generating a unique 3-oxo-L-alanine residue that is essential for sulfatase activity. The exact nature of the thiol involved is still not clear - dithiothreitol and cysteamine are the most efficiently used thiols in vitro. Glutathione alo acts in vitro, but it is not known whether it is used in vivo.

Links to other databases: BRENDA, EXPASY, KEGG, MetaCyc, CAS registry number:

References:

1. Dierks, T., Schmidt, B. and von Figura, K. Conversion of cysteine to formylglycine: a protein modification in the endoplasmic reticulum. Proc. Natl. Acad. Sci. USA 94 (1997) 11963-11968. [PMID: 9342345]

2. Dierks, T., Miech, C., Hummerjohann, J., Schmidt, B., Kertesz, M.A. and von Figura, K. Posttranslational formation of formylglycine in prokaryotic sulfatases by modification of either cysteine or serine. J. Biol. Chem. 273 (1998) 25560-25564. [PMID: 9748219]

3. Preusser-Kunze, A., Mariappan, M., Schmidt, B., Gande, S.L., Mutenda, K., Wenzel, D., von Figura, K. and Dierks, T. Molecular characterization of the human Cα-formylglycine-generating enzyme. J. Biol. Chem. 280 (2005) 14900-14910. [PMID: 15657036]

4. Roeser, D., Preusser-Kunze, A., Schmidt, B., Gasow, K., Wittmann, J.G., Dierks, T., von Figura, K. and Rudolph, M.G. A general binding mechanism for all human sulfatases by the formylglycine-generating enzyme. Proc. Natl. Acad. Sci. USA 103 (2006) 81-86. [PMID: 16368756]

5. Carlson, B.L., Ballister, E.R., Skordalakes, E., King, D.S., Breidenbach, M.A., Gilmore, S.A., Berger, J.M. and Bertozzi, C.R. Function and structure of a prokaryotic formylglycine-generating enzyme. J. Biol. Chem. 283 (2008) 20117-20125. [PMID: 18390551]

6. Holder, P.G., Jones, L.C., Drake, P.M., Barfield, R.M., Banas, S., de Hart, G.W., Baker, J. and Rabuka, D. Reconstitution of formylglycine-generating enzyme with copper(II) for aldehyde tag conversion. J. Biol. Chem. 290 (2015) 15730-15745. [PMID: 25931126]

7. Knop, M., Engi, P., Lemnaru, R. and Seebeck, F.P. In vitro reconstitution of formylglycine-generating enzymes requires copper(I). Chembiochem 16 (2015) 2147-2150. [PMID: 26403223]

8. Knop, M., Dang, T.Q., Jeschke, G. and Seebeck, F.P. Copper is a cofactor of the formylglycine-generating enzyme. Chembiochem 18 (2017) 161-165. [PMID: 27862795]

9. Meury, M., Knop, M. and Seebeck, F.P. Structural basis for copper-oxygen mediated C-H bond activation by the formylglycine-generating enzyme. Angew. Chem. Int. Ed. Engl. (2017) . [PMID: 28544744]

[EC 1.8.3.7 created 2014]


EC 1.8.4 With a disulfide as acceptor

Contents

EC 1.8.4.1 glutathione—homocystine transhydrogenase
EC 1.8.4.2 protein-disulfide reductase (glutathione)
EC 1.8.4.3 glutathione—CoA-glutathione transhydrogenase
EC 1.8.4.4 glutathione—cystine transhydrogenase
EC 1.8.4.5 now EC 1.8.4.13 and EC 1.8.4.14
EC 1.8.4.6 now EC 1.8.4.11
EC 1.8.4.7 enzyme-thiol transhydrogenase (glutathione-disulfide)
EC 1.8.4.8 phosphoadenylyl-sulfate reductase (thioredoxin)
EC 1.8.4.9 adenylyl-sulfate reductase (glutathione)
EC 1.8.4.10 adenylyl-sulfate reductase (thioredoxin)
EC 1.8.4.11 peptide-methionine (S)-S-oxide reductase
EC 1.8.4.12 peptide-methionine (R)-S-oxide reductase
EC 1.8.4.13 L-methionine (S)-S-oxide reductase
EC 1.8.4.14 L-methionine (R)-S-oxide reductase
EC 1.8.4.15 protein dithiol oxidoreductase (disulfide-forming)
EC 1.8.4.16 thioredoxin:protein disulfide reductase


EC 1.8.4.1

Accepted name: glutathione—homocystine transhydrogenase

Reaction: 2 glutathione + homocystine = glutathione disulfide + 2 homocysteine

Systematic name: glutathione:homocystine oxidoreductase

Comments: The reactions catalysed by this enzyme and by others in this subclass may be similar to those catalysed by EC 2.5.1.18 glutathione transferase.

Links to other databases: BRENDA, EXPASY, KEGG, Metacyc, CAS registry number: 9029-40-7

References:

1. Racker, E. Glutathione-homocystine transhydrogenase. J. Biol. Chem. 217 (1955) 867-874.

[EC 1.8.4.1 created 1961]

EC 1.8.4.2

Accepted name: protein-disulfide reductase (glutathione)

Reaction: 2 glutathione + protein-disulfide = glutathione-disulfide + protein-dithiol

Other name(s): glutathione-insulin transhydrogenase; insulin reductase; reductase, protein disulfide (glutathione); protein disulfide transhydrogenase; glutathione-protein disulfide oxidoreductase; protein disulfide reductase (glutathione); GSH-insulin transhydrogenase; protein-disulfide interchange enzyme; protein-disulfide isomerase/oxidoreductase; thiol:protein-disulfide oxidoreductase; thiol-protein disulphide oxidoreductase

Systematic name: glutathione:protein-disulfide oxidoreductase

Comments: Reduces insulin and some other proteins.

Links to other databases: BRENDA, EXPASY, KEGG, Metacyc, PDB, CAS registry number: 9082-53-5

References:

1. Katzen, H.M., Tietze, F. and Stetten, D. Further studies on the properties of hepatic glutathione-insulin transhydrogenase J. Biol. Chem. 238 (1963) 1006-1011.

2. Kohnert, K.-D., Hahn, H.-J., Zühlke, H., Schmidt, S. and Fiedler, H. Breakdown of exogenous insulin by Langerhans islets of the pancreas in vitro. Biochim. Biophys. Acta 338 (1974) 68-77.

[EC 1.8.4.2 created 1965]

EC 1.8.4.3

Accepted name: glutathione—CoA-glutathione transhydrogenase

Reaction: CoA + glutathione disulfide = CoA-glutathione + glutathione

Other name(s): glutathione-coenzyme A glutathione disulfide transhydrogenase; glutathione-coenzyme A glutathione disulfide transhydrogenase; glutathione coenzyme A-glutathione transhydrogenase; glutathione:coenzyme A-glutathione transhydrogenase; coenzyme A:oxidized-glutathione oxidoreductase

Systematic name: CoA:glutathione-disulfide oxidoreductase

Links to other databases: BRENDA, EXPASY, GTD, KEGG, Metacyc, CAS registry number: 37256-48-7

References:

1. Chang, S.H. and Wilken, D.R. Participation of the unsymmetrical disulfide of coenzyme A and glutathione in an enzymatic sulfhydryl-disulfide interchange. I. Partial purification and properties of the bovine kidney enzyme. J. Biol. Chem. 241 (1966) 4251-4260. [PMID: 5924646]

[EC 1.8.4.3 created 1972]

EC 1.8.4.4

Accepted name: glutathione—cystine transhydrogenase

Reaction: 2 glutathione + cystine = glutathione disulfide + 2 cysteine

Other name(s): GSH-cystine transhydrogenase; NADPH-dependent GSH-cystine transhydrogenase

Systematic name: glutathione:cystine oxidoreductase

Links to other databases: BRENDA, EXPASY, KEGG, Metacyc, CAS registry number: 37256-49-8

References:

1. Nagai, S. and Black, S. A thiol-disulfide transhydrogenase from yeast. J. Biol. Chem. 243 (1968) 1942-1947. [PMID: 5646485]

[EC 1.8.4.4 created 1972]

[EC 1.8.4.5 Transferred entry: methionine-S-oxide reductase. Now EC 1.8.4.13, L-methionine (S)-S-oxide reductase and EC 1.8.4.14, L-methionine (R)-S-oxide reductase. (EC 1.8.4.5 created 1984, deleted 2006)]

[EC 1.8.4.6 Transferred entry: protein-methionine-S-oxide reductase. Proved to be due to EC 1.8.4.11, peptide-methionine (S)-S-oxide reductase. (EC 1.8.4.6 created 1984, deleted 2006)]

EC 1.8.4.7

Accepted name: enzyme-thiol transhydrogenase (glutathione-disulfide)

Reaction: [xanthine dehydrogenase] + glutathione disulfide = [xanthine oxidase] + 2 glutathione

Other name(s): [xanthine-dehydrogenase]:oxidized-glutathione S-oxidoreductase; enzyme-thiol transhydrogenase (oxidized-glutathione); glutathione-dependent thiol:disulfide oxidoreductase; thiol:disulphide oxidoreductase

Systematic name: [xanthine-dehydrogenase]:glutathione-disulfide S-oxidoreductase

Comments: Converts EC 1.17.1.4 xanthine dehydrogenase into EC 1.17.3.2 xanthine oxidase in the presence of glutathione disulfide; also reduces the disulfide bond of ricin. Not inhibited by Cu2+ or thiol reagents.

Links to other databases: BRENDA, EXPASY, KEGG, Metacyc, CAS registry number: 85030-79-1

References:

1. Battelli, M.G. and Lorenzoni, E. Purification and properties of a new glutathione-dependent thiol:disulphide oxidoreductase from rat liver. Biochem. J. 207 (1982) 133-138. [PMID: 6960894]

[EC 1.8.4.7 created 1989, modified 2002]

EC 1.8.4.8

Accepted name: phosphoadenylyl-sulfate reductase (thioredoxin)

Reaction: adenosine 3',5'-bisphosphate + sulfite + thioredoxin disulfide = 3'-phosphoadenylyl sulfate + thioredoxin

Glossary and synonyms entries: 3'-phosphoadenylyl sulfate = PAPS

Other name(s): PAPS reductase, thioredoxin-dependent; PAPS reductase; thioredoxin:adenosine 3'-phosphate 5'-phosphosulfate reductase; 3'-phosphoadenylylsulfate reductase; thioredoxin:3'-phospho-adenylylsulfate reductase; phosphoadenosine-phosphosulfate reductase; adenosine 3',5'-bisphosphate,sulfite:oxidized-thioredoxin oxidoreductase (3'-phosphoadenosine-5'-phosphosulfate-forming)

Systematic name: adenosine 3',5'-bisphosphate,sulfite:thioredoxin-disulfide oxidoreductase (3'-phosphoadenosine-5'-phosphosulfate-forming)

Comments: specific for PAPS. The enzyme from Escherichia coli will use thioredoxins from other species.

Links to other databases: BRENDA, EXPASY, KEGG, Metacyc, PDB, CAS registry number: 9068-63-7

References:

1. Berendt, U., Haverkamp, T., Prior, A., Schwenn, J.D. Reaction mechanism of thioredoxin: 3'-phospho-adenylylsulfate reductase investigated by site-directed mutagenesis. Eur. J. Biochem. 233 (1995) 347-356. [PMID: 7588765]

[EC 1.8.4.8 created 1999 as EC 1.8.99.4, transferred 2000 to EC 1.8.4.8]

EC 1.8.4.9

Accepted name: adenylyl-sulfate reductase (glutathione)

Reaction: AMP + sulfite + glutathione disulfide = adenylyl sulfate + 2 glutathione

Other name(s): 5'-adenylylsulfate reductase (also used for EC 1.8.99.2); AMP,sulfite:oxidized-glutathione oxidoreductase (adenosine-5'-phosphosulfate-forming); plant-type 5'-adenylylsulfate reductase

Systematic name: AMP,sulfite:glutathione-disulfide oxidoreductase (adenosine-5'-phosphosulfate-forming)

Comments: This enzyme differs from EC 1.8.99.2, adenylyl-sulfate reductase, in using glutathione as the reductant. Glutathione can be replaced by γ-glutamylcysteine or dithiothreitol, but not by thioredoxin, glutaredoxin or 2-sulfanylethan-1-ol (2-mercaptoethanol). The enzyme from the mouseear cress, Arabidopsis thaliana, contains a glutaredoxin-like domain. The enzyme is also found in other photosynthetic eukaryotes, e.g., the Madagascar periwinkle, Catharanthus roseus and the hollow green seaweed, Enteromorpha intestinalis.

Links to other databases: BRENDA, EXPASY, KEGG, Metacyc, PDB, CAS registry number: 355840-27-6

References:

1. Gutierrez-Marcos, J.F., Roberts, M.A., Campbell, E.I. and Wray, J.L. Three members of a novel small gene-family from Arabidopsis thaliana able to complement functionally an Escherichia coli mutant defective in PAPS reductase activity encode proteins with a thioredoxin-like domain and 'APS reductase' activity. Proc. Natl. Acad. Sci. USA 93 (1996) 13377-13382. [PMID: 8917599]

2. Setya, A., Murillo, M. and Leustek, T. Sulfate reduction in higher plants: Molecular evidence for a novel 5-adenylylphosphosulfate (APS) reductase. Proc. Natl. Acad. Sci. USA 93 (1996) 13383-13388. [PMID: 8917600]

3. Bick, J.A., Aslund, F., Cen, Y. and Leustek, T. Glutaredoxin function for the carboxyl-terminal domain of the plant-type 5'-adenylylsulfate reductase. Proc. Natl. Acad. Sci. USA 95 (1998) 8404-8409. [PMID: 9653199]

[EC 1.8.4.9 created 2000, modified 2002]

EC 1.8.4.10

Accepted name: adenylyl-sulfate reductase (thioredoxin)

Reaction: AMP + sulfite + thioredoxin disulfide = 5'-adenylyl sulfate + thioredoxin

Other name(s): thioredoxin-dependent 5'-adenylylsulfate reductase

Systematic name: AMP,sulfite:thioredoxin-disulfide oxidoreductase (adenosine-5'-phosphosulfate-forming)

Comments: Uses adenylyl sulfate, not phosphoadenylyl sulfate, distinguishing this enzyme from EC 1.8.4.8, phosphoadenylyl-sulfate reductase (thioredoxin). Uses thioredoxin as electron donor, not glutathione or other donors, distinguishing it from EC 1.8.4.9 [adenylyl-sulfate reductase (glutathione)] and EC 1.8.99.2 (adenylyl-sulfate reductase).

Links to other databases: BRENDA, EXPASY, KEGG, Metacyc, PDB, CAS registry number:

References:

1. Bick, J.A., Dennis, J.J., Zylstra, G.J., Nowack, J. and Leustek, T. Identification of a new class of 5-adenylylsulfate (APS) reductase from sulfate-assimilating bacteria. J. Bacteriol. 182 (2000) 135-142. [PMID: 10613872]

2. Abola, A.P., Willits, M.G., Wang, R.C. and Long, S.R. Reduction of adenosine-5'-phosphosulfate instead of 3'-phosphoadenosine-5'-phosphosulfate in cysteine biosynthesis by Rhizobium meliloti and other members of the family Rhizobiaceae. J. Bacteriol. 181 (1999) 5280-5287. [PMID: 10464198]

3. Williams, S.J., Senaratne, R.H., Mougous, J.D., Riley, L.W. and Bertozzi, C.R. 5'-Adenosinephosphosulfate lies at a metabolic branchpoint in mycobacteria. J. Biol. Chem. 277 (2002) 32606-32615. [PMID: 12072441]

4. Neumann, S., Wynen, A., Trüper, H.G. and Dahl, C. Characterization of the cys gene locus from Allochromatium vinosum indicates an unusual sulfate assimilation pathway. Mol. Biol. Rep. 27 (2000) 27-33. [PMID: 10939523]

[EC 1.8.4.10 created 2003]

EC 1.8.4.11

Accepted name: peptide-methionine (S)-S-oxide reductase

Reaction: (1) peptide-L-methionine + thioredoxin disulfide + H2O = peptide-L-methionine (S)-S-oxide + thioredoxin
(2) L-methionine + thioredoxin disulfide + H2O = L-methionine (S)-S-oxide + thioredoxin

For diagram click here and mechanism click here.

Other name(s): MsrA; methionine sulfoxide reductase (ambiguous); methionine sulphoxide reductase A; methionine S-oxide reductase (ambiguous); methionine S-oxide reductase (S-form oxidizing); methionine sulfoxide reductase A; peptide methionine sulfoxide reductase

Systematic name: peptide-L-methionine:thioredoxin-disulfide S-oxidoreductase [L-methionine (S)-S-oxide-forming]

Comments: The reaction occurs in the reverse direction to that shown above. The enzyme exhibits high specificity for the reduction of the S-form of L-methionine S-oxide, acting faster on the residue in a peptide than on the free amino acid [9]. On the free amino acid, it can also reduce D-methionine (S)-S-oxide but more slowly [9]. The enzyme plays a role in preventing oxidative-stress damage caused by reactive oxygen species by reducing the oxidized form of methionine back to methionine and thereby reactivating peptides that had been damaged. In some species, e.g. Neisseria meningitidis, both this enzyme and EC 1.8.4.12, methionine (R)-S-oxide reductase, are found within the same protein whereas, in other species, they are separate proteins [1,4]. The reaction proceeds via a sulfenic-acid intermediate [5,10].

Links to other databases: BRENDA, EXPASY, KEGG, Metacyc, PDB, CAS registry number:

References:

1. Moskovitz, J., Singh, V.K., Requena, J., Wilkinson, B.J., Jayaswal, R.K. and Stadtman, E.R. Purification and characterization of methionine sulfoxide reductases from mouse and Staphylococcus aureus and their substrate stereospecificity. Biochem. Biophys. Res. Commun. 290 (2002) 62-65. [PMID: 11779133]

2. Taylor, A.B., Benglis, D.M., Jr., Dhandayuthapani, S. and Hart, P.J. Structure of Mycobacterium tuberculosis methionine sulfoxide reductase A in complex with protein-bound methionine. J. Bacteriol. 185 (2003) 4119-4126. [PMID: 12837786]

3. Singh, V.K. and Moskovitz, J. Multiple methionine sulfoxide reductase genes in Staphylococcus aureus: expression of activity and roles in tolerance of oxidative stress. Microbiology 149 (2003) 2739-2747. [PMID: 14523107]

4. Boschi-Muller, S., Olry, A., Antoine, M. and Branlant, G. The enzymology and biochemistry of methionine sulfoxide reductases. Biochim. Biophys. Acta 1703 (2005) 231-238. [PMID: 15680231]

5. Ezraty, B., Aussel, L. and Barras, F. Methionine sulfoxide reductases in prokaryotes. Biochim. Biophys. Acta 1703 (2005) 221-229. [PMID: 15680230]

6. Weissbach, H., Resnick, L. and Brot, N. Methionine sulfoxide reductases: history and cellular role in protecting against oxidative damage. Biochim. Biophys. Acta 1703 (2005) 203-212. [PMID: 15680228]

7. Kauffmann, B., Aubry, A. and Favier, F. The three-dimensional structures of peptide methionine sulfoxide reductases: current knowledge and open questions. Biochim. Biophys. Acta 1703 (2005) 249-260. [PMID: 15680233]

8. Vougier, S., Mary, J. and Friguet, B. Subcellular localization of methionine sulphoxide reductase A (MsrA): evidence for mitochondrial and cytosolic isoforms in rat liver cells. Biochem. J. 373 (2003) 531-537. [PMID: 12693988]

9. Olry, A., Boschi-Muller, S., Marraud, M., Sanglier-Cianferani, S., Van Dorsselear, A. and Branlant, G. Characterization of the methionine sulfoxide reductase activities of PILB, a probable virulence factor from Neisseria meningitidis. J. Biol. Chem. 277 (2002) 12016-12022. [PMID: 11812798]

10. Boschi-Muller, S., Olry, A., Antoine, M. and Branlant, G. The enzymology and biochemistry of methionine sulfoxide reductases. Biochim. Biophys. Acta 1703 (2005) 231-238. [PMID: 15680231]

11. Brot, N., Weissbach, L., Werth, J. and Weissbach, H. Enzymatic reduction of protein-bound methionine sulfoxide. Proc. Natl. Acad. Sci. USA 78 (1981) 2155-2158. [PMID: 7017726]

[EC 1.8.4.11 created 2006]

EC 1.8.4.12

Accepted name: peptide-methionine (R)-S-oxide reductase

Reaction: peptide-L-methionine + thioredoxin disulfide + H2O = peptide-L-methionine (R)-S-oxide + thioredoxin

For diagram click here and mechanism click here.

Other name(s): MsrB; methionine sulfoxide reductase (ambiguous); pMSR; methionine S-oxide reductase (ambiguous); selenoprotein R; methionine S-oxide reductase (R-form oxidizing); methionine sulfoxide reductase B; SelR; SelX; PilB; pRMsr

Systematic name: peptide-methionine:thioredoxin-disulfide S-oxidoreductase [methionine (R)-S-oxide-forming]

Comments: The reaction occurs in the reverse direction to that shown above. The enzyme exhibits high specificity for reduction of the R-form of methionine S-oxide, with higher activity being observed with L-methionine S-oxide than with D-methionine S-oxide [9]. While both free and protein-bound methionine (R)-S-oxide act as substrates, the activity with the peptide-bound form is far greater [10]. The enzyme plays a role in preventing oxidative-stress damage caused by reactive oxygen species by reducing the oxidized form of methionine back to methionine and thereby reactivating peptides that had been damaged. In some species, e.g. Neisseria meningitidis, both this enzyme and EC 1.8.4.11, peptide-methionine (S)-S-oxide reductase, are found within the same protein whereas in other species, they are separate proteins [3,5]. The reaction proceeds via a sulfenic-acid intermediate [5,10]. For MsrB2 and MsrB3, thioredoxin is a poor reducing agent but thionein works well [11]. The enzyme from some species contains selenocysteine and Zn2+.

Links to other databases: BRENDA, EXPASY, KEGG, Metacyc, PDB, CAS registry number:

References:

1. Moskovitz, J., Singh, V.K., Requena, J., Wilkinson, B.J., Jayaswal, R.K. and Stadtman, E.R. Purification and characterization of methionine sulfoxide reductases from mouse and Staphylococcus aureus and their substrate stereospecificity. Biochem. Biophys. Res. Commun. 290 (2002) 62-65. [PMID: 11779133]

2. Taylor, A.B., Benglis, D.M., Jr., Dhandayuthapani, S. and Hart, P.J. Structure of Mycobacterium tuberculosis methionine sulfoxide reductase A in complex with protein-bound methionine. J. Bacteriol. 185 (2003) 4119-4126. [PMID: 12837786]

3. Singh, V.K. and Moskovitz, J. Multiple methionine sulfoxide reductase genes in Staphylococcus aureus: expression of activity and roles in tolerance of oxidative stress. Microbiology 149 (2003) 2739-2747. [PMID: 14523107]

4. Boschi-Muller, S., Olry, A., Antoine, M. and Branlant, G. The enzymology and biochemistry of methionine sulfoxide reductases. Biochim. Biophys. Acta 1703 (2005) 231-238. [PMID: 15680231]

5. Ezraty, B., Aussel, L. and Barras, F. Methionine sulfoxide reductases in prokaryotes. Biochim. Biophys. Acta 1703 (2005) 221-229. [PMID: 15680230]

6. Weissbach, H., Resnick, L. and Brot, N. Methionine sulfoxide reductases: history and cellular role in protecting against oxidative damage. Biochim. Biophys. Acta 1703 (2005) 203-212. [PMID: 15680228]

7. Kauffmann, B., Aubry, A. and Favier, F. The three-dimensional structures of peptide methionine sulfoxide reductases: current knowledge and open questions. Biochim. Biophys. Acta 1703 (2005) 249-260. [PMID: 15680233]

8. Vougier, S., Mary, J. and Friguet, B. Subcellular localization of methionine sulphoxide reductase A (MsrA): evidence for mitochondrial and cytosolic isoforms in rat liver cells. Biochem. J. 373 (2003) 531-537. [PMID: 12693988]

9. Olry, A., Boschi-Muller, S., Marraud, M., Sanglier-Cianferani, S., Van Dorsselear, A. and Branlant, G. Characterization of the methionine sulfoxide reductase activities of PILB, a probable virulence factor from Neisseria meningitidis. J. Biol. Chem. 277 (2002) 12016-12022. [PMID: 11812798]

10. Boschi-Muller, S., Olry, A., Antoine, M. and Branlant, G. The enzymology and biochemistry of methionine sulfoxide reductases. Biochim. Biophys. Acta 1703 (2005) 231-238. [PMID: 15680231]

11. Sagher, D., Brunell, D., Hejtmancik, J.F., Kantorow, M., Brot, N. and Weissbach, H. Thionein can serve as a reducing agent for the methionine sulfoxide reductases. Proc. Natl. Acad. Sci. USA 103 (2006) 8656-8661. [PMID: 16735467]

[EC 1.8.4.12 created 2006]

EC 1.8.4.13

Accepted name: L-methionine (S)-S-oxide reductase

Reaction: L-methionine + thioredoxin disulfide + H2O = L-methionine (S)-S-oxide + thioredoxin

For diagram click here and mechanism click here.

Other name(s): fSMsr; methyl sulfoxide reductase I and II; acetylmethionine sulfoxide reductase; methionine sulfoxide reductase; L-methionine:oxidized-thioredoxin S-oxidoreductase; methionine-S-oxide reductase; free-methionine (S)-S-oxide reductase

Systematic name: L-methionine:thioredoxin-disulfide S-oxidoreductase

Comments: Requires NADPH [2]. The reaction occurs in the opposite direction to that given above. Dithiothreitol can replace reduced thioredoxin. L-Methionine (R)-S-oxide is not a substrate [see EC 1.8.4.14, L-methionine (R)-S-oxide reductase].

Links to other databases: BRENDA, EXPASY, KEGG, Metacyc, PDB, CAS registry number:

References:

1. Black, S., Harte, E.M., Hudson, B. and Wartofsky, L. A specific enzymatic reduction of L-(–)methionine sulfoxide and a related nonspecific reduction of diulfides. J. Biol. Chem. 235 (1960) 2910-2916.

2. Ejiri, S.-I., Weissbach, H. and Brot, N. Reduction of methionine sulfoxide to methionine by Escherichia coli. J. Bacteriol. 139 (1979) 161-164. [PMID: 37234]

3. Ejiri, S.-I., Weissbach, H. and Brot, N. The purification of methionine sulfoxide reductase from Escherichia coli. Anal. Biochem. 102 (1980) 393-398. [PMID: 6999943]

4. Weissbach, H., Resnick, L. and Brot, N. Methionine sulfoxide reductases: history and cellular role in protecting against oxidative damage. Biochim. Biophys. Acta 1703 (2005) 203-212. [PMID: 15680228]

[EC 1.8.4.13 created 1984 as EC 1.8.4.5, part transferred 2006 to EC 1.8.4.13]

EC 1.8.4.14

Accepted name: L-methionine (R)-S-oxide reductase

Reaction: L-methionine + thioredoxin disulfide + H2O = L-methionine (R)-S-oxide + thioredoxin

For diagram click here and mechanism click here.

Other name(s): fRMsr; FRMsr; free met-R-(o) reductase; free-methionine (R)-S-oxide reductase

Systematic name: L-methionine:thioredoxin-disulfide S-oxidoreductase [L-methionine (R)-S-oxide-forming]

Comments: Requires NADPH. Unlike EC 1.8.4.12, peptide-methionine (R)-S-oxide reductase, this enzyme cannot use peptide-bound methionine (R)-S-oxide as a substrate [1]. Differs from EC 1.8.4.13, L-methionine (S)-S-oxide in that L-methionine (S)-S-oxide is not a substrate.

Links to other databases: BRENDA, EXPASY, KEGG, Metacyc, PDB, CAS registry number: 945954-12-1

References:

1. Etienne, F., Spector, D., Brot, N. and Weissbach, H. A methionine sulfoxide reductase in Escherichia coli that reduces the R enantiomer of methionine sulfoxide. Biochem. Biophys. Res. Commun. 300 (2003) 378-382. [PMID: 12504094]

[EC 1.8.4.14 created 1984 as EC 1.8.4.5, part transferred 2006 to EC 1.8.4.14]

EC 1.8.4.15

Accepted name: protein dithiol oxidoreductase (disulfide-forming)

Reaction: a [DsbA protein] carrying a disulfide bond + a [protein] with reduced L-cysteine residues = a [DsbA protein] with reduced L-cysteine residues + a [protein] carrying a disulfide bond

Other name(s): dsbA (gene name)

Systematic name: protein dithiol:[DsbA protein] oxidoreductase (protein disulfide-forming)

Comments: DsbA is a periplasmic thiol:disulfide oxidoreductase found in Gram-negative bacteria that promotes protein disulfide bond formation. DsbA contains a redox active disulfide bond that is catalytically transferred via disulfide exchange to a diverse range of newly translocated protein substrates. The protein is restored to the oxidized state by EC 1.8.5.9, protein dithiol:quinone oxidoreductase DsbB.

Links to other databases: BRENDA, EXPASY, KEGG, MetaCyc, CAS registry number:

References:

1. Bardwell, J.C., McGovern, K. and Beckwith, J. Identification of a protein required for disulfide bond formation in vivo. Cell 67 (1991) 581-589. [PMID: 1934062]

2. Akiyama, Y., Kamitani, S., Kusukawa, N. and Ito, K. In vitro catalysis of oxidative folding of disulfide-bonded proteins by the Escherichia coli dsbA (ppfA) gene product. J. Biol. Chem 267 (1992) 22440-22445. [PMID: 1429594]

3. Zapun, A., Bardwell, J.C. and Creighton, T.E. The reactive and destabilizing disulfide bond of DsbA, a protein required for protein disulfide bond formation in vivo. Biochemistry 32 (1993) 5083-5092. [PMID: 8494885]

4. Bader, M., Muse, W., Zander, T. and Bardwell, J. Reconstitution of a protein disulfide catalytic system. J. Biol. Chem 273 (1998) 10302-10307. [PMID: 9553083]

5. Guddat, L.W., Bardwell, J.C. and Martin, J.L. Crystal structures of reduced and oxidized DsbA: investigation of domain motion and thiolate stabilization. Structure 6 (1998) 757-767. [PMID: 9655827]

6. Kadokura, H., Tian, H., Zander, T., Bardwell, J.C. and Beckwith, J. Snapshots of DsbA in action: detection of proteins in the process of oxidative folding. Science 303 (2004) 534-537. [PMID: 14739460]

[EC 1.8.4.15 created 2019]

EC 1.8.4.16

Accepted name: thioredoxin:protein disulfide reductase

Reaction: a [protein] with reduced L-cysteine residues + thioredoxin disulfide = a [protein] carrying a disulfide bond + thioredoxin (overall reaction)
(1a) a [thioredoxin:protein disulfide reductase] with reduced L-cysteine residues + thioredoxin disulfide = a [thioredoxin:protein disulfide reductase] carrying a disulfide bond + thioredoxin
(1b) a [thioredoxin:protein disulfide reductase] carrying a disulfide bond + a [protein] with reduced L-cysteine residues = a [thioredoxin:protein disulfide reductase] with reduced L-cysteine residues + a [protein] carrying a disulfide bond

Other name(s): dsbD (gene name); dipZ (gene name)

Systematic name: thioredoxin:protein disulfide oxidoreductase (dithiol-forming)

Comments: The DsbD protein is found in Gram-negative bacteria and transfers electrons from cytoplasmic thioredoxin to the periplasmic substrate proteins DsbC, DsbG and CcmG, reducing disulfide bonds in the target proteins to dithiols. NrdH redoxins, which are found in Gram-positive bacteria, catalyse a similar reaction.

Links to other databases: BRENDA, EXPASY, KEGG, MetaCyc, CAS registry number:

References:

1. Missiakas, D., Schwager, F. and Raina, S. Identification and characterization of a new disulfide isomerase-like protein (DsbD) in Escherichia coli. EMBO J. 14 (1995) 3415-3424. [PMID: 7628442]

2. Gordon, E.H., Page, M.D., Willis, A.C. and Ferguson, S.J. Escherichia coli DipZ: anatomy of a transmembrane protein disulphide reductase in which three pairs of cysteine residues, one in each of three domains, contribute differentially to function. Mol. Microbiol. 35 (2000) 1360-1374. [PMID: 10760137]

3. Katzen, F. and Beckwith, J. Transmembrane electron transfer by the membrane protein DsbD occurs via a disulfide bond cascade. Cell 103 (2000) 769-779. [PMID: 11114333]

4. Goulding, C.W., Sawaya, M.R., Parseghian, A., Lim, V., Eisenberg, D. and Missiakas, D. Thiol-disulfide exchange in an immunoglobulin-like fold: structure of the N-terminal domain of DsbD. Biochemistry 41 (2002) 6920-6927. [PMID: 12033924]

5. Katzen, F. and Beckwith, J. Role and location of the unusual redox-active cysteines in the hydrophobic domain of the transmembrane electron transporter DsbD. Proc. Natl. Acad. Sci. USA 100 (2003) 10471-10476. [PMID: 12925743]

6. Rozhkova, A. and Glockshuber, R. Thermodynamic aspects of DsbD-mediated electron transport. J. Mol. Biol. 380 (2008) 783-788. [PMID: 18571669]

7. Si, M.R., Zhang, L., Yang, Z.F., Xu, Y.X., Liu, Y.B., Jiang, C.Y., Wang, Y., Shen, X.H. and Liu, S.J. NrdH Redoxin enhances resistance to multiple oxidative stresses by acting as a peroxidase cofactor in Corynebacterium glutamicum. Appl. Environ. Microbiol. 80 (2014) 1750-1762. [PMID: 24375145]

[EC 1.8.4.16 created 2019, modified 2023]


EC 1.8.5 With a quinone or similar compound as acceptor

Contents

EC 1.8.5.1 glutathione dehydrogenase (ascorbate)
EC 1.8.5.2 thiosulfate dehydrogenase (quinone)
EC 1.8.5.3 respiratory dimethylsulfoxide reductase
EC 1.8.5.4 bacterial sulfide:quinone reductase
EC 1.8.5.5 thiosulfate reductase (quinone)
EC 1.8.5.6 sulfite dehydrogenase (quinone)
EC 1.8.5.7 glutathionyl-hydroquinone reductase
EC 1.8.5.8 eukaryotic sulfide quinone oxidoreductase
EC 1.8.5.9 protein dithiol:quinone oxidoreductase DsbB
EC 1.8.5.10 [DsrC]-trisulfide reductase

EC 1.8.5.1

Accepted name: glutathione dehydrogenase (ascorbate)

Reaction: 2 glutathione + dehydroascorbate = glutathione disulfide + ascorbate

Other name(s): dehydroascorbic reductase; dehydroascorbic acid reductase; glutathione dehydroascorbate reductase; DHA reductase ; dehydroascorbate reductase; GDOR; glutathione:dehydroascorbic acid oxidoreductase

Systematic name: glutathione:dehydroascorbate oxidoreductase

Links to other databases: BRENDA, EXPASY, KEGG, Metacyc, PDB, CAS registry number: 9026-38-4

References:

1. Crook, E.M. The system dehydroascorbic acid-glutathione. Biochem. J. 35 (1941) 226-236.

[EC 1.8.5.1 created 1961]

EC 1.8.5.2

Accepted name: thiosulfate dehydrogenase (quinone)

Reaction: 2 thiosulfate + 6-decylubiquinone = tetrathionate + 6-decylubiquinol

Other name(s): thiosulfate:quinone oxidoreductase; thiosulphate:quinone oxidoreductase; thiosulfate oxidoreductase, tetrathionate-forming; TQO

Systematic name: thiosulfate:6-decylubiquinone oxidoreductase

Comments: The reaction can also proceed with ferricyanide as the electron acceptor, but more slowly. Unlike EC 1.8.2.2, thiosulfate dehydrogenase, this enzyme cannot utilize cytochrome c as an acceptor.

Links to other databases: BRENDA, EXPASY, KEGG, Metacyc, CAS registry number:

References:

1. Müller, F.H., Bandeiras, T.M., Urich, T., Teixeira, M., Gomes, C.M. and Kletzin, A. Coupling of the pathway of sulfur oxidation to dioxygen reduction: characterization of a novel membrane-bound thiosulfate:quinone oxidoreductase. Mol. Microbiol. 53 (2004) 1147-1160. [PMID: 15306018]

[EC 1.8.5.2 created 2004]

EC 1.8.5.3

Accepted name: respiratory dimethylsulfoxide reductase

Reaction: dimethylsulfide + menaquinone + H2O = dimethylsulfoxide + menaquinol

For diagram of reaction click here.

Other name(s): dmsABC (gene names); DMSO reductase (ambiguous); dimethylsulfoxide reductase (ambiguous)

Systematic name: dimethyl sulfide:menaquinone oxidoreductase

Comments: The enzyme participates in bacterial electron transfer pathways in which dimethylsulfoxide (DMSO) is the terminal electron acceptor. It is composed of three subunits - DmsA contains a bis(guanylyl molybdopterin) cofactor and a [4Fe-4S] cluster, DmsB is an iron-sulfur protein, and DmsC is a transmembrane protein that anchors the enzyme and accepts electrons from the quinol pool. The electrons are passed through DmsB to DmsA and on to DMSO. The enzyme can also reduce pyridine-N-oxide and trimethylamine N-oxide to the corresponding amines with lower activity.

Links to other databases: BRENDA, EXPASY, KEGG, MetaCyc, PDB, CAS registry number:

References:

1. Daruwala, R. and Meganathan, R. Dimethyl sulfoxide reductase is not required for trimethylamine N-oxide reduction in Escherichia coli. FEMS Microbiol. Lett. 67 (1991) 255-259. [PMID: 1769531]

2. Miguel, L. and Meganthan, R. Electron donors and the quinone involved in dimethyl sulfoxide reduction in Escherichia coli. Curr. Microbiol. 22 (1991) 109-115.

3. Simala-Grant, J.L. and Weiner, J.H. Kinetic analysis and substrate specificity of Escherichia coli dimethyl sulfoxide reductase. Microbiology 142 (1996) 3231-3239. [PMID: 8969520]

4. Rothery, R.A., Trieber, C.A. and Weiner, J.H. Interactions between the molybdenum cofactor and iron-sulfur clusters of Escherichia coli dimethylsulfoxide reductase. J. Biol. Chem. 274 (1999) 13002-13009. [PMID: 10224050]

[EC 1.8.5.3 created 2011, modified 2019]

EC 1.8.5.4

Accepted name: bacterial sulfide:quinone reductase

Reaction: n HS- + n quinone = polysulfide + n quinol

Other name(s): sqr (gene name); sulfide:quinone reductase (ambiguous); sulfide:quinone oxidoreductase

Systematic name: sulfide:quinone oxidoreductase (polysulfide-producing)

Comments: Contains FAD. Ubiquinone, plastoquinone or menaquinone can act as acceptor in different species. In some organisms the enzyme catalyses the formation of sulfur globules. It repeats the catalytic cycle without releasing the product, producing a polysulfide of up to 10 sulfur atoms. The reaction stops when the maximum length of the polysulfide that can be accommodated in the sulfide oxidation pocket is achieved. The enzyme also plays an important role in anoxygenic bacterial photosynthesis. cf. EC 1.8.5.8, sulfide quinone oxidoreductase.

Links to other databases: BRENDA, EXPASY, KEGG, MetaCyc, PDB, CAS registry number:

References:

1. Arieli, B., Shahak, Y., Taglicht, D., Hauska, G. and Padan, E. Purification and characterization of sulfide-quinone reductase, a novel enzyme driving anoxygenic photosynthesis in Oscillatoria limnetica. J. Biol. Chem. 269 (1994) 5705-5711. [PMID: 8119908]

2. Reinartz, M., Tschape, J., Bruser, T., Truper, H.G. and Dahl, C. Sulfide oxidation in the phototrophic sulfur bacterium Chromatium vinosum. Arch. Microbiol. 170 (1998) 59-68. [PMID: 9639604]

3. Nubel, T., Klughammer, C., Huber, R., Hauska, G. and Schutz, M. Sulfide:quinone oxidoreductase in membranes of the hyperthermophilic bacterium Aquifex aeolicus (VF5). Arch. Microbiol. 173 (2000) 233-244. [PMID: 10816041]

4. Brito, J.A., Sousa, F.L., Stelter, M., Bandeiras, T.M., Vonrhein, C., Teixeira, M., Pereira, M.M. and Archer, M. Structural and functional insights into sulfide:quinone oxidoreductase. Biochemistry 48 (2009) 5613-5622. [PMID: 19438211]

5. Cherney, M.M., Zhang, Y., Solomonson, M., Weiner, J.H. and James, M.N. Crystal structure of sulfide:quinone oxidoreductase from Acidithiobacillus ferrooxidans: insights into sulfidotrophic respiration and detoxification. J. Mol. Biol. 398 (2010) 292-305. [PMID: 20303979]

6. Marcia, M., Langer, J.D., Parcej, D., Vogel, V., Peng, G. and Michel, H. Characterizing a monotopic membrane enzyme. Biochemical, enzymatic and crystallization studies on Aquifex aeolicus sulfide:quinone oxidoreductase. Biochim. Biophys. Acta 1798 (2010) 2114-2123. [PMID: 20691146]

7. Xin, Y., Liu, H., Cui, F., Liu, H. and Xun, L. Recombinant Escherichia coli with sulfide:quinone oxidoreductase and persulfide dioxygenase rapidly oxidises sulfide to sulfite and thiosulfate via a new pathway. Environ Microbiol 18 (2016) 5123-5136. [PMID: 27573649]

[EC 1.8.5.4 created 2011, modified 2017]

EC 1.8.5.5

Accepted name: thiosulfate reductase (quinone)

Reaction: sulfite + hydrogen sulfide + a quinone = thiosulfate + a quinol

Other name(s): phsABC (gene names)

Systematic name: sulfite,hydrogen sulfide:quinone oxidoreductase

Comments: The enzyme, characterized from the bacterium Salmonella enterica, is similar to EC 1.17.5.3, formate dehydrogenase-N. It contains a molybdopterin-guanine dinucleotide, five [4Fe-4S] clusters and two heme b groups. The reaction occurs in vivo in the direction of thiosulfate disproportionation, which is highly endergonic. It is driven by the proton motive force that occurs across the cytoplasmic membrane.

Links to other databases: BRENDA, EXPASY, KEGG, MetaCyc, CAS registry number:

References:

1. Kwan, H.S. and Barrett, E.L. Map locations and functions of Salmonella typhimurium men genes. J. Bacteriol. 159 (1984) 1090-1092. [PMID: 6384182]

2. Clark, M.A. and Barrett, E.L. The phs gene and hydrogen sulfide production by Salmonella typhimurium. J. Bacteriol. 169 (1987) 2391-2397. [PMID: 3108233]

3. Alami, N. and Hallenbeck, P.C. Cloning and characterization of a gene cluster, phsBCDEF, necessary for the production of hydrogen sulfide from thiosulfate by Salmonella typhimurium. Gene 156 (1995) 53-57. [PMID: 7737516]

4. Heinzinger, N.K., Fujimoto, S.Y., Clark, M.A., Moreno, M.S. and Barrett, E.L. Sequence analysis of the phs operon in Salmonella typhimurium and the contribution of thiosulfate reduction to anaerobic energy metabolism. J. Bacteriol. 177 (1995) 2813-2820. [PMID: 7751291]

5. Stoffels, L., Krehenbrink, M., Berks, B.C. and Unden, G. Thiosulfate reduction in Salmonella enterica is driven by the proton motive force. J. Bacteriol. 194 (2012) 475-485. [PMID: 22081391]

[EC 1.8.5.5 created 2016, modified 2017]

EC 1.8.5.6

Accepted name: sulfite dehydrogenase (quinone)

Reaction: sulfite + a quinone + H2O = sulfate + a quinol

Other name(s): soeABC (gene names)

Systematic name: sulfite:quinone oxidoreductase

Comments: This membrane-bound bacterial enzyme catalyses the direct oxidation of sulfite to sulfate in the cytoplasm. The enzyme, characterized from the bacteria Ruegeria pomeroyi and Allochromatium vinosum, is a complex that consists of a membrane anchor (SoeC) and two cytoplasmic subunits: an iron-sulfur protein (SoeB) and a molybdoprotein that contains a [4Fe-4S] iron-sulfur cluster (SoeA). cf. EC 1.8.2.1, sulfite dehydrogenase (cytochrome).

Links to other databases: BRENDA, EXPASY, KEGG, Metacyc, CAS registry number:

References:

1. Dahl, C., Franz, B., Hensen, D., Kesselheim, A. and Zigann, R. Sulfite oxidation in the purple sulfur bacterium Allochromatium vinosum: identification of SoeABC as a major player and relevance of SoxYZ in the process. Microbiology 159 (2013) 2626-2638. [PMID: 24030319]

[EC 1.8.5.6 created 2016]

EC 1.8.5.7

Accepted name: glutathionyl-hydroquinone reductase

Reaction: glutathione + 2-(glutathione-S-yl)-hydroquinone = glutathione disulfide + hydroquinone

Other name(s): pcpF (gene name); yqjG (gene name)

Systematic name: 2-(glutathione-S-yl)-hydroquinone:glutathione oxidoreductase

Comments: This type of enzymes, which are found in bacteria, halobacteria, fungi, and plants, catalyse the glutathione-dependent reduction of glutathionyl-hydroquinones. The enzyme from the bacterium Sphingobium chlorophenolicum can act on halogenated substrates such as 2,6-dichloro-3-(glutathione-S-yl)-hydroquinone and 2,3,5-trichloro-6-(glutathione-S-yl)-hydroquinone. Substrates for these enzymes are often formed spontaneously by interaction of benzoquinones with glutathione.

Links to other databases: BRENDA, EXPASY, KEGG, MetaCyc, PDB, CAS registry number:

References:

1. Huang, Y., Xun, R., Chen, G. and Xun, L. Maintenance role of a glutathionyl-hydroquinone lyase (PcpF) in pentachlorophenol degradation by Sphingobium chlorophenolicum ATCC 39723. J. Bacteriol. 190 (2008) 7595-7600. [PMID: 18820023]

2. Xun, L., Belchik, S.M., Xun, R., Huang, Y., Zhou, H., Sanchez, E., Kang, C. and Board, P.G. S-Glutathionyl-(chloro)hydroquinone reductases: a novel class of glutathione transferases. Biochem. J. 428 (2010) 419-427. [PMID: 20388120]

3. Lam, L.K., Zhang, Z., Board, P.G. and Xun, L. Reduction of benzoquinones to hydroquinones via spontaneous reaction with glutathione and enzymatic reaction by S-glutathionyl-hydroquinone reductases. Biochemistry 51 (2012) 5014-5021. [PMID: 22686328]

4. Green, A.R., Hayes, R.P., Xun, L. and Kang, C. Structural understanding of the glutathione-dependent reduction mechanism of glutathionyl-hydroquinone reductases. J. Biol. Chem. 287 (2012) 35838-35848. [PMID: 22955277]

[EC 1.8.5.7 created 2017]

EC 1.8.5.8

Accepted name: eukaryotic sulfide quinone oxidoreductase

Reaction: hydrogen sulfide + glutathione + a quinone = S-sulfanylglutathione + a quinol

Other name(s): SQR; SQOR; SQRDL (gene name)

Systematic name: sulfide:glutathione,quinone oxidoreductase

Comments: Contains FAD. This eukaryotic enzyme, located at the inner mitochondrial membrane, catalyses the first step in the metabolism of sulfide. While both sulfite and glutathione have been shown to act as sulfane sulfur acceptors in vitro, it is thought that the latter acts as the main acceptor in vivo. The electrons are transferred via FAD and quinones to the electron transfer chain. Unlike the bacterial homolog (EC 1.8.5.4, bacterial sulfide:quinone reductase), which repeats the catalytic cycle without releasing the product, producing a polysulfide, the eukaryotic enzyme transfers the persulfide to an acceptor at the end of each catalytic cycle.

Links to other databases: BRENDA, EXPASY, KEGG, MetaCyc, PDB, CAS registry number:

References:

1. Vande Weghe, J.G. and Ow, D.W. A fission yeast gene for mitochondrial sulfide oxidation. J. Biol. Chem. 274 (1999) 13250-13257. [PMID: 10224084]

2. Hildebrandt, T.M. and Grieshaber, M.K. Three enzymatic activities catalyze the oxidation of sulfide to thiosulfate in mammalian and invertebrate mitochondria. FEBS J. 275 (2008) 3352-3361. [PMID: 18494801]

3. Jackson, M.R., Melideo, S.L. and Jorns, M.S. Human sulfide:quinone oxidoreductase catalyzes the first step in hydrogen sulfide metabolism and produces a sulfane sulfur metabolite. Biochemistry 51 (2012) 6804-6815. [PMID: 22852582]

4. Libiad, M., Yadav, P.K., Vitvitsky, V., Martinov, M. and Banerjee, R. Organization of the human mitochondrial hydrogen sulfide oxidation pathway. J. Biol. Chem. 289 (2014) 30901-30910. [PMID: 25225291]

[EC 1.8.5.8 created 2017]

EC 1.8.5.9

Accepted name: protein dithiol:quinone oxidoreductase DsbB

Reaction: a [DsbA protein] with reduced L-cysteine residues + a quinone = a [DsbA protein] carrying a disulfide bond + a quinol (overall reaction)
(1a) a [DsbA protein] with reduced L-cysteine residues + a [DsbB protein] carrying a disulfide bond = a [DsbA protein] carrying a disulfide bond + a [DsbB protein] with reduced L-cysteine residues
(1b) a [DsbB protein] with reduced L-cysteine residues + a quinone = a [DsbB protein] carrying a disulfide bond + a quinol

Other name(s): dsbB (gene name)

Systematic name: protein dithiol:quinone oxidoreductase (disulfide-forming)

Comments: DsbB is a protein found in Gram-negative bacteria that functions within a pathway for protein disulfide bond formation. The enzyme catalyses the oxidation of the DsbA protein by generating disulfide bonds de novo via the reduction of membrane quinones. cf. EC 1.8.4.15, protein dithiol oxidoreductase (disulfide-forming)

Links to other databases: BRENDA, EXPASY, KEGG, MetaCyc, CAS registry number:

References:

1. Guilhot, C., Jander, G., Martin, N.L. and Beckwith, J. Evidence that the pathway of disulfide bond formation in Escherichia coli involves interactions between the cysteines of DsbB and DsbA. Proc. Natl Acad. Sci. USA 92 (1995) 9895-9899. [PMID: 7568240]

2. Kishigami, S., Kanaya, E., Kikuchi, M. and Ito, K. DsbA-DsbB interaction through their active site cysteines. Evidence from an odd cysteine mutant of DsbA. J. Biol. Chem 270 (1995) 17072-17074. [PMID: 7615498]

3. Kishigami, S. and Ito, K. Roles of cysteine residues of DsbB in its activity to reoxidize DsbA, the protein disulphide bond catalyst of Escherichia coli. Genes Cells 1 (1996) 201-208. [PMID: 9140064]

4. Collet, J.F. and Bardwell, J.C. Oxidative protein folding in bacteria. Mol. Microbiol. 44 (2002) 1-8. [PMID: 11967064]

5. Dutton, R.J., Boyd, D., Berkmen, M. and Beckwith, J. Bacterial species exhibit diversity in their mechanisms and capacity for protein disulfide bond formation. Proc. Natl Acad. Sci. USA 105 (2008) 11933-11938. [PMID: 18695247]

6. Inaba, K. Disulfide bond formation system in Escherichia coli. J. Biochem. 146 (2009) 591-597. [PMID: 19567379]

[EC 1.8.5.9 created 2019]

EC 1.8.5.10

Accepted name: [DsrC]-trisulfide reductase

Reaction: hydrogen sulfide + a [DsrC protein]-dithiol + 2 quinone = a [DsrC protein]-trisulfide + 2 quinol

Other name(s): DsrMKJOP complex

Systematic name: hydrogen sulfide:[DsrC protein]-dithiol oxidoreductase (trisulfide-forming)

Comments: This enzyme complex is present in both sulfate-reducing bacteria and sulfur-oxidizing bacteria, and acts in opposite directions during the reductive and oxidative pathways, respectively. DsrM and DsrP contain b-type hemes, DsrJ contains c-type hemes, DsrO is a ferredoxin-like protein, and DsrK is the catalytic subunit that acts as a disulfide reductase on DsrC proteins that contain a trisulfide bridge [1,3,4]. The complex receives the electrons from the membrane quinone pool [2,3].

Links to other databases: BRENDA, EXPASY, KEGG, MetaCyc, CAS registry number:

References:

1. Pott, A.S. and Dahl, C. Sirohaem sulfite reductase and other proteins encoded by genes at the dsr locus of Chromatium vinosum are involved in the oxidation of intracellular sulfur. Microbiology (Reading) 144 (1998) 1881-1894. [PMID: 9695921]

2. Pires, R.H., Venceslau, S.S., Morais, F., Teixeira, M., Xavier, A.V. and Pereira, I.A. Characterization of the Desulfovibrio desulfuricans ATCC 27774 DsrMKJOP complex - a membrane-bound redox complex involved in the sulfate respiratory pathway. Biochemistry 45 (2006) 249-262. [PMID: 16388601]

3. Grein, F., Pereira, I.A. and Dahl, C. Biochemical characterization of individual components of the Allochromatium vinosum DsrMKJOP transmembrane complex aids understanding of complex function in vivo. J. Bacteriol. 192 (2010) 6369-6377. [PMID: 20952577]

4. Santos, A.A., Venceslau, S.S., Grein, F., Leavitt, W.D., Dahl, C., Johnston, D.T. and Pereira, I.A. A protein trisulfide couples dissimilatory sulfate reduction to energy conservation. Science 350 (2015) 1541-1545. [PMID: 26680199]

[EC 1.8.5.10 created 2023]


EC 1.8.6 With nitrogenous group as acceptor

[EC 1.8.6.1 Deleted entry: Nitrate-ester reductase. Now included with EC 2.5.1.18 glutathione transferase (EC 1.8.6.1 created 1961, deleted 1976)]


EC 1.8.7 With an iron-sulfur protein as acceptor

Contents

EC 1.8.7.1 assimilatory sulfite reductase (ferredoxin)
EC 1.8.7.2 ferredoxin:thioredoxin reductase
EC 1.8.7.3 ferredoxin:CoB-CoM heterodisulfide reductase
EC 1.8.7.3 ferredoxin:CoB-CoM heterodisulfide reductase

EC 1.8.7.1

Accepted name: assimilatory sulfite reductase (ferredoxin)

Reaction: hydrogen sulfide + 6 oxidized ferredoxin [iron-sulfur] cluster + 3 H2O = sulfite + 6 reduced ferredoxin [iron-sulfur] cluster + 6 H+

Other name(s): ferredoxin-sulfite reductase; SIR (gene name); sulfite reductase (ferredoxin)

Systematic name: hydrogen-sulfide:ferredoxin oxidoreductase

Comments: An iron protein. The enzyme participates in sulfate assimilation. While it is usually found in cyanobacteria, plants and algae, it has also been reported in bacteria [4]. Different from EC 1.8.99.5
, dissimilatory sulfite reductase, which is involved in prokaryotic sulfur-based energy metabolism. cf.
EC 1.8.1.2
, assimilatory sulfite reductase (NADPH).

Links to other databases: BRENDA, EXPASY, KEGG, MetaCyc, PDB, CAS registry number: 37256-50-1

References:

1. Schmidt, A. and Trebst, A. The mechanism of photosynthetic sulfate reduction by isolated chloroplasts. Biochim. Biophys. Acta 180 (1969) 529-535. [PMID: 4390248]

2. Gisselmann, G., Klausmeier, P. and Schwenn, J.D. The ferredoxin:sulphite reductase gene from Synechococcus PCC7942. Biochim. Biophys. Acta 1144 (1993) 102-106. [PMID: 8347657]

3. Bork, C., Schwenn, J.D. and Hell, R. Isolation and characterization of a gene for assimilatory sulfite reductase from Arabidopsis thaliana. Gene 212 (1998) 147-153. [PMID: 9661674]

4. Neumann, S., Wynen, A., Truper, H.G. and Dahl, C. Characterization of the cys gene locus from Allochromatium vinosum indicates an unusual sulfate assimilation pathway. Mol. Biol. Rep. 27 (2000) 27-33. [PMID: 10939523]

[EC 1.8.7.1 created 1972, modified 2015]

EC 1.8.7.2

Accepted name: ferredoxin:thioredoxin reductase

Reaction: 2 reduced ferredoxin + thioredoxin disulfide + 2 H+ = 2 oxidized ferredoxin + thioredoxin

Systematic name: ferredoxin:thioredoxin disulfide oxidoreductase

Comments: The enzyme contains a [4Fe-4S] cluster and internal disulfide. It forms a mixed disulfide with thioredoxin on one side, and docks ferredoxin on the other side, enabling two one-electron transfers. The reduced thioredoxins generated by the enzyme activate the Calvin cycle enzymes EC 3.1.3.11 (fructose-bisphosphatase), EC 3.1.3.37 (sedoheptulose-bisphosphatase) and EC 2.7.1.19 (phosphoribulokinase) as well as other chloroplast enzymes by disulfide reduction.

Links to other databases: BRENDA, EXPASY, KEGG, MetaCyc, PDB, CAS registry number:

References:

1. Buchanan, B.B. Regulation of CO2 assimilation in oxygenic photosynthesis: the ferredoxin/thioredoxin system. Perspective on its discovery, present status, and future development. Arch. Biochem. Biophys. 288 (1991) 1-9. [PMID: 1910303]

2. Chow, L.P., Iwadate, H., Yano, K., Kamo, M., Tsugita, A., Gardet-Salvi, L., Stritt-Etter, A.L. and Schurmann, P. Amino acid sequence of spinach ferredoxin:thioredoxin reductase catalytic subunit and identification of thiol groups constituting a redox-active disulfide and a [4Fe-4S] cluster. Eur. J. Biochem. 231 (1995) 149-156. [PMID: 7628465]

3. Staples, C.R., Ameyibor, E., Fu, W., Gardet-Salvi, L., Stritt-Etter, A.L., Schurmann, P., Knaff, D.B. and Johnson, M.K. The function and properties of the iron-sulfur center in spinach ferredoxin: thioredoxin reductase: a new biological role for iron-sulfur clusters. Biochemistry 35 (1996) 11425-11434. [PMID: 8784198]

[EC 1.8.7.2 created 2010, modified 2023]

EC 1.8.7.3

Accepted name: ferredoxin:CoB-CoM heterodisulfide reductase

Reaction: 2 oxidized ferredoxin [iron-sulfur] cluster + CoB + CoM = 2 reduced ferredoxin [iron-sulfur] cluster + CoM-S-S-CoB + 2 H+

Glossary: CoB = coenzyme B = N-(7-mercaptoheptanoyl)threonine 3-O-phosphate = N-(7-thioheptanoyl)-3-O-phosphothreonine
CoM = coenzyme M = 2-sulfanylethane-1-sulfonate = 2-mercaptoethanesulfonate (deprecated)
CoM-S-S-CoB = CoB-CoM heterodisulfide = N-{7-[(2-sulfoethyl)dithio]heptanoyl}-O3-phospho-L-threonine

Other name(s): hdrABC (gene names); hdrA1B1C1 (gene names); hdrA2B2C2 (gene names)

Systematic name: CoB,CoM:ferredoxin oxidoreductase

Comments: HdrABC is an enzyme complex that is found in most methanogens and catalyses the reduction of the CoB-CoM heterodisulfide back to CoB and CoM. HdrA contains a FAD cofactor that acts as the entry point for electrons, which are transferred via HdrC to the HdrB catalytic subunit. One form of the enzyme from Methanosarcina acetivorans (HdrA2B2C2) can also catalyse EC 1.8.98.4, coenzyme F420:CoB-CoM heterodisulfide,ferredoxin reductase. cf. EC 1.8.98.5, H2:CoB-CoM heterodisulfide,ferredoxin reductase, EC 1.8.98.6, formate:CoB-CoM heterodisulfide,ferredoxin reductase, and EC 1.8.98.1, dihydromethanophenazine:CoB-CoM heterodisulfide reductase.

Links to other databases: BRENDA, EXPASY, KEGG, MetaCyc, CAS registry number:

References:

1. Buan, N.R. and Metcalf, W.W. Methanogenesis by Methanosarcina acetivorans involves two structurally and functionally distinct classes of heterodisulfide reductase. Mol. Microbiol. 75 (2010) 843-853. [PMID: 19968794]

2. Yan, Z., Wang, M. and Ferry, J.G. A ferredoxin- and F420H2-dependent, electron-bifurcating, heterodisulfide reductase with homologs in the domains Bacteria and Archaea. mBio 8 (2017) e02285-16. [PMID: 28174314]

[EC 1.8.7.3 created 2017]


EC 1.8.98 With other, known, physiological acceptors

Contents

EC 1.8.98.1 dihydromethanophenazine:CoB-CoM heterodisulfide reductase
EC 1.8.98.2 sulfiredoxin
EC 1.8.98.3 sulfite reductase (coenzyme F420)
EC 1.8.98.4 coenzyme F420:CoB-CoM heterodisulfide,ferredoxin reductase
EC 1.8.98.5 H2:CoB-CoM heterodisulfide,ferredoxin reductase
EC 1.8.99.5 transferred now EC 1.8.1.22
EC 1.8.98.6 formate:CoB-CoM heterodisulfide,ferredoxin reductase
EC 1.8.98.7 cysteine-type anaerobic sulfatase-maturating enzyme


EC 1.8.98.1

Accepted name: dihydromethanophenazine:CoB-CoM heterodisulfide reductase

Reaction: CoB + CoM + methanophenazine = CoM-S-S-CoB + dihydromethanophenazine

For diagram of reaction click here

Glossary: CoB = coenzyme B = N-(7-mercaptoheptanoyl)threonine 3-O-phosphate
CoB = coenzyme M = 2-sulfanylethane-1-sulfonate = 2-mercaptoethanesulfonate (deprecated)
methanophenazine = 2-{[(6E,10E,14E)-3,7,11,15,19-pentamethylicosa-6,10,14,18-tetraen-1-yl]oxy}phenazine
CoM-S-S-CoB = CoB-CoM heterodisulfide = N-{7-[(2-sulfoethyl)dithio]heptanoyl}-O3-phospho-L-threonine

Other name(s): hdrDE (gene names); CoB–CoM heterodisulfide reductase (ambiguous); heterodisulfide reductase (ambiguous); coenzyme B:coenzyme M:methanophenazine oxidoreductase

Systematic name: CoB:CoM:methanophenazine oxidoreductase

Comments: This enzyme, found in methanogenic archaea that belong to the Methanosarcinales order, regenerates CoM and CoB after the action of EC 2.8.4.1, coenzyme-B sulfoethylthiotransferase. It is a membrane-bound enzyme that contains (per heterodimeric unit) two distinct b-type hemes and two [4Fe-4S] clusters. cf. EC 1.8.7.3, ferredoxin:CoB-CoM heterodisulfide reductase, EC 1.8.98.5, H2:CoB-CoM heterodisulfide,ferredoxin reductase, EC 1.8.98.6, formate:CoB-CoM heterodisulfide,ferredoxin reductase and EC 1.8.98.4, coenzyme F420:CoB-CoM heterodisulfide,ferredoxin reductase.

Links to other databases: BRENDA, EXPASY, KEGG, MetaCyc, PDB, CAS registry number:

References:

1. Hedderich, R., Berkessel, A. and Thauer, R.K. Purification and properties of heterodisulfide reductase from Methanobacterium thermoautotrophicum (strain Marburg). Eur. J. Biochem. 193 (1990) 255-261. [PMID: 2121478]

2. Abken, H.J., Tietze, M., Brodersen, J., Bäumer, S., Beifuss, U. and Deppenmeier, U. Isolation and characterization of methanophenazine and function of phenazines in membrane-bound electron transport of Methanosarcina mazei gol. J. Bacteriol. 180 (1998) 2027-2032. [PMID: 9555882]

3. Simianu, M., Murakami, E., Brewer, J.M. and Ragsdale, S.W. Purification and properties of the heme- and iron-sulfur-containing heterodisulfide reductase from Methanosarcina thermophila. Biochemistry 37 (1998) 10027-10039. [PMID: 9665708]

4. Murakami, E., Deppenmeier, U. and Ragsdale, S.W. Characterization of the intramolecular electron transfer pathway from 2-hydroxyphenazine to the heterodisulfide reductase from Methanosarcina thermophila. J. Biol. Chem. 276 (2001) 2432-2439. [PMID: 11034998]

[EC 1.8.98.1 created 2003, modified 2017]

EC 1.8.98.2

Accepted name: sulfiredoxin

Reaction: peroxiredoxin-(S-hydroxy-S-oxocysteine) + ATP + 2 R-SH = peroxiredoxin-(S-hydroxycysteine) + ADP + phosphate + R-S-S-R

Other name(s): Srx1; sulphiredoxin; peroxiredoxin-(S-hydroxy-S-oxocysteine) reductase

Systematic name: peroxiredoxin-(S-hydroxy-S-oxocysteine):thiol oxidoreductase [ATP-hydrolysing; peroxiredoxin-(S-hydroxycysteine)-forming]

Comments: In the course of the reaction of EC 1.11.1.15, peroxiredoxin, its cysteine residue is alternately oxidized to the sulfenic acid, S-hydroxycysteine, and reduced back to cysteine. Occasionally the S-hydroxycysteine residue is further oxidized to the sulfinic acid S-hydroxy-S-oxocysteine, thereby inactivating the enzyme. The reductase provides a mechanism for regenerating the active form of peroxiredoxin, i.e. the peroxiredoxin-(S-hydroxycysteine) form. Apparently the reductase first catalyses the phosphorylation of the -S(O)-OH group by ATP to give -S(O)-O-P, which is attached to the peroxiredoxin by a cysteine residue, forming an -S(O)-S- link between the two enzymes. Attack by a thiol splits this bond, leaving the peroxiredoxin as the sulfenic acid and the reductase as the thiol.

Links to other databases: BRENDA, EXPASY, KEGG, Metacyc, PDB, CAS registry number: 710319-61-2

References:

1. Biteau, B., Labarre, J. and Toledano, M.B. ATP-dependent reduction of cysteine-sulphinic acid by S. cerevisiae sulphiredoxin. Nature 425 (2003) 980-984. [PMID: 14586471]

2. Chang, T.S., Jeong, W., Woo, H.A., Lee, S.M., Park, S. and Rhee, S.G. Characterization of mammalian sulfiredoxin and its reactivation of hyperoxidized peroxiredoxin through reduction of cysteine sulfinic acid in the active site to cysteine. J. Biol. Chem. 279 (2004) 50994-51001. [PMID: 15448164]

3. Woo, H.A., Jeong, W., Chang, T.S., Park, K.J., Park, S.J., Yang, J.S. and Rhee, S.G. Reduction of cysteine sulfinic acid by sulfiredoxin is specific to 2-Cys peroxiredoxins. J. Biol. Chem. 280 (2005) 3125-3128. [PMID: 15590625]

[EC 1.8.98.2 created 2005]

EC 1.8.98.3

Accepted name: sulfite reductase (coenzyme F420)

Reaction: hydrogen sulfide + 3 oxidized coenzyme F420 + 3 H2O = sulfite + 3 reduced coenzyme F420

Other name(s): coenzyme F420-dependent sulfite reductase; Fsr

Systematic name: hydrogen sulfide:coenzyme F420 oxidoreductase

Comments: The enzyme, isolated from the archaeon Methanocaldococcus jannaschii, is involved in sulfite detoxification and assimilation.

Links to other databases: BRENDA, EXPASY, KEGG, Metacyc, PDB, CAS registry number:

References:

1. Johnson, E.F. and Mukhopadhyay, B. A new type of sulfite reductase, a novel coenzyme F420-dependent enzyme, from the methanarchaeon Methanocaldococcus jannaschii. J. Biol. Chem. 280 (2005) 38776-38786. [PMID: 16048999]

2. Johnson, E.F. and Mukhopadhyay, B. Coenzyme F420-dependent sulfite reductase-enabled sulfite detoxification and use of sulfite as a sole sulfur source by Methanococcus maripaludis. Appl. Environ. Microbiol. 74 (2008) 3591-3595. [PMID: 18378657]

[EC 1.8.98.3 created 2014]

EC 1.8.98.4

Accepted name: coenzyme F420:CoB-CoM heterodisulfide,ferredoxin reductase

Reaction: 2 oxidized coenzyme F420 + 2 reduced ferredoxin [iron-sulfur] cluster + CoB + CoM + 2 H+ = 2 reduced coenzyme F420 + 2 oxidized ferredoxin [iron-sulfur] cluster + CoM-S-S-CoB

Glossary: CoB = coenzyme B = N-(7-mercaptoheptanoyl)threonine 3-O-phosphate = N-(7-thioheptanoyl)-3-O-phosphothreonine
CoM = coenzyme M = 2-sulfanylethane-1-sulfonate = 2-mercaptoethanesulfonate (deprecated)
CoM-S-S-CoB = CoB-CoM heterodisulfide = N-{7-[(2-sulfoethyl)dithio]heptanoyl}-O3-phospho-L-threonine

Other name(s): hdrA2B2C2 (gene names)

Systematic name: CoB,CoM,ferredoxin:coenzyme F420 oxidoreductase

Comments: The enzyme, characterized from the archaeon Methanosarcina acetivorans, catalyses the reduction of CoB-CoM heterodisulfide back to CoB and CoM. The enzyme consists of three components, HdrA, HdrB and HdrC, all of which contain [4Fe-4S] clusters. Electrons enter at HdrA, which also contains FAD, and are transferred via HdrC to the catalytic component, HdrB. During methanogenesis from acetate the enzyme catalyses the activity of EC 1.8.7.3, ferredoxin:CoB-CoM heterodisulfide reductase. However, it can also use electron bifurcation to direct electron pairs from reduced coenzyme F420 towards the reduction of both ferredoxin and CoB-CoM heterodisulfide. This activity is proposed to take place during Fe(III)-dependent anaerobic methane oxidation. cf. EC 1.8.98.5, H2:CoB-CoM heterodisulfide,ferredoxin reductase, EC 1.8.98.6, formate:CoB-CoM heterodisulfide,ferredoxin reductase, and EC 1.8.98.1, dihydromethanophenazine:CoB-CoM heterodisulfide reductase.

Links to other databases: BRENDA, EXPASY, KEGG, MetaCyc, CAS registry number:

References:

1. Yan, Z., Wang, M. and Ferry, J.G. A ferredoxin- and F420H2-dependent, electron-bifurcating, heterodisulfide reductase with homologs in the domains Bacteria and Archaea. mBio 8 (2017) e02285-16. [PMID: 28174314]

[EC 1.8.98.4 created 2017]

EC 1.8.98.5

Accepted name: H2:CoB-CoM heterodisulfide,ferredoxin reductase

Reaction: 2 reduced ferredoxin [iron-sulfur] cluster + CoB + CoM + 2 H+ = 2 H2 + 2 oxidized ferredoxin [iron-sulfur] cluster + CoM-S-S-CoB

Glossary: CoB = coenzyme B = N-(7-mercaptoheptanoyl)threonine 3-O-phosphate = N-(7-thioheptanoyl)-3-O-phosphothreonine
CoM = coenzyme M = 2-sulfanylethane-1-sulfonate = 2-mercaptoethanesulfonate (deprecated)
CoM-S-S-CoB = CoB-CoM heterodisulfide = N-{7-[(2-sulfoethyl)dithio]heptanoyl}-O3-phospho-L-threonine

Systematic name: CoB,CoM,ferredoxin:H2 oxidoreductase

Comments: This enzyme complex is found in H2-oxidizing CO2-reducing methanogenic archaea such as Methanothermobacter thermautotrophicus. It consists of a cytoplasmic complex of HdrABC reductase and MvhAGD hydrogenase. Electron pairs donated by the hydrogenase are transferred via its δ subunit to the HdrA subunit of the reductase, where they are bifurcated, reducing both ferredoxin and CoB-CoM heterodisulfide. The reductase can also form a similar complex with formate dehydrogenase, see EC 1.8.98.6, formate:CoB-CoM heterodisulfide,ferredoxin reductase. cf. EC 1.8.7.3, ferredoxin:CoB-CoM heterodisulfide reductase, EC 1.8.98.4, coenzyme F420:CoB-CoM heterodisulfide,ferredoxin reductase, and EC 1.8.98.1, dihydromethanophenazine:CoB-CoM heterodisulfide reductase.

Links to other databases: BRENDA, EXPASY, KEGG, MetaCyc, CAS registry number:

References:

1. Reeve, J.N., Beckler, G.S., Cram, D.S., Hamilton, P.T., Brown, J.W., Krzycki, J.A., Kolodziej, A.F., Alex, L., Orme-Johnson, W.H. and Walsh, C.T. A hydrogenase-linked gene in Methanobacterium thermoautotrophicum strain δ H encodes a polyferredoxin. Proc. Natl Acad. Sci. USA 86 (1989) 3031-3035. [PMID: 2654933]

2. Hedderich, R., Koch, J., Linder, D. and Thauer, R.K. The heterodisulfide reductase from Methanobacterium thermoautotrophicum contains sequence motifs characteristic of pyridine-nucleotide-dependent thioredoxin reductases. Eur. J. Biochem. 225 (1994) 253-261. [PMID: 7925445]

3. Setzke, E., Hedderich, R., Heiden, S. and Thauer, R.K. H2: heterodisulfide oxidoreductase complex from Methanobacterium thermoautotrophicum. Composition and properties. Eur. J. Biochem. 220 (1994) 139-148. [PMID: 8119281]

4. Stojanowic, A., Mander, G.J., Duin, E.C. and Hedderich, R. Physiological role of the F420-non-reducing hydrogenase (Mvh) from Methanothermobacter marburgensis. Arch. Microbiol. 180 (2003) 194-203. [PMID: 12856108]

5. Kaster, A.K., Moll, J., Parey, K. and Thauer, R.K. Coupling of ferredoxin and heterodisulfide reduction via electron bifurcation in hydrogenotrophic methanogenic archaea. Proc. Natl Acad. Sci. USA 108 (2011) 2981-2986. [PMID: 21262829]

6. Costa, K.C., Lie, T.J., Xia, Q. and Leigh, J.A. VhuD facilitates electron flow from H2 or formate to heterodisulfide reductase in Methanococcus maripaludis. J. Bacteriol. 195 (2013) 5160-5165. [PMID: 24039260]

[EC 1.8.98.5 created 2017]

EC 1.8.98.6

Accepted name: formate:CoB-CoM heterodisulfide,ferredoxin reductase

Reaction: 2 CO2 + 2 reduced ferredoxin [iron-sulfur] cluster + CoB + CoM + 2 H+ = 2 formate + 2 oxidized ferredoxin [iron-sulfur] cluster + CoM-S-S-CoB

Glossary: coenzyme B = CoB = N-(7-mercaptoheptanoyl)threonine 3-O-phosphate = N-(7-thioheptanoyl)-3-O-phosphothreonine
coenzyme M = CoM = 2-sulfanylethane-1-sulfonate = 2-mercaptoethanesulfonate (deprecated)
CoM-S-S-CoB = CoB-CoM heterodisulfide = N-{7-[(2-sulfoethyl)dithio]heptanoyl}-O3-phospho-L-threonine

Systematic name: coenzyme B,coenzyme M,ferredoxin:formate oxidoreductase

Comments: The enzyme is found in formate-oxidizing CO2-reducing methanogenic archaea such as Methanococcus maripaludis. It consists of a cytoplasmic complex of HdrABC reductase and formate dehydrogenase. Electron pairs donated by formate dehydrogenase are transferred to the HdrA subunit of the reductase, where they are bifurcated, reducing both ferredoxin and CoB-CoM heterodisulfide. cf. EC 1.8.7.3, ferredoxin:CoB-CoM heterodisulfide reductase, EC 1.8.98.4, coenzyme F420:CoB-CoM heterodisulfide,ferredoxin reductase, EC 1.8.98.5, H2:CoB-CoM heterodisulfide,ferredoxin reductase, and EC 1.8.98.1, dihydromethanophenazine:CoB-CoM heterodisulfide reductase.

Links to other databases: BRENDA, EXPASY, KEGG, MetaCyc, CAS registry number:

References:

1. Costa, K.C., Wong, P.M., Wang, T., Lie, T.J., Dodsworth, J.A., Swanson, I., Burn, J.A., Hackett, M. and Leigh, J.A. Protein complexing in a methanogen suggests electron bifurcation and electron delivery from formate to heterodisulfide reductase. Proc. Natl Acad. Sci. USA 107 (2010) 11050-11055. [PMID: 20534465]

2. Costa, K.C., Lie, T.J., Xia, Q. and Leigh, J.A. VhuD facilitates electron flow from H2 or formate to heterodisulfide reductase in Methanococcus maripaludis. J. Bacteriol. 195 (2013) 5160-5165. [PMID: 24039260]

[EC 1.8.98.6 created 2017]

EC 1.8.98.7

Accepted name: cysteine-type anaerobic sulfatase-maturating enzyme

Reaction: S-adenosyl-L-methionine + a [sulfatase]-L-cysteine + H2O = a [sulfatase]-3-oxo-L-alanine + 5'-deoxyadenosine + L-methionine + hydrogen sulfide

Glossary: 3-oxo-L-alanine = formylglycine = Cα-formylglycine = FGly

Other name(s): anSME; Cys-type anaerobic sulfatase-maturating enzyme; anaerobic sulfatase maturase

Systematic name: [sulfatase]-L-cysteine:S-adenosyl-L-methionine oxidoreductase (3-oxo-L-alanine-forming)

Comments: A radical S-adenosylmethionine (AdoMet) enzyme that contains three [4Fe-4S] clusters. The enzyme, found in some bacteria, activates a type I sulfatase enzyme (EC 3.1.6.1) by converting a conserved L-cysteine residue in the active site to a unique 3-oxo-L-alanine residue that is essential for the sulfatase activity. Some enzymes can also act on L-serine, see EC 1.1.98.7, serine-type anaerobic sulfatase-maturating enzyme and EC 1.8.3.7, formylglycine-generating enzyme.

Links to other databases: BRENDA, EXPASY, KEGG, MetaCyc, PDB, CAS registry number:

References:

1. Berteau, O., Guillot, A., Benjdia, A. and Rabot, S. A new type of bacterial sulfatase reveals a novel maturation pathway in prokaryotes. J. Biol. Chem. 281 (2006) 22464-22470. [PMID: 16766528]

2. Benjdia, A., Subramanian, S., Leprince, J., Vaudry, H., Johnson, M.K. and Berteau, O. Anaerobic sulfatase-maturating enzymes, first dual substrate radical S-adenosylmethionine enzymes. J. Biol. Chem. 283 (2008) 17815-17826. [PMID: 18408004]

3. Benjdia, A., Leprince, J., Sandstrom, C., Vaudry, H. and Berteau, O. Mechanistic investigations of anaerobic sulfatase-maturating enzyme: direct Cβ H-atom abstraction catalyzed by a radical AdoMet enzyme. J. Am. Chem. Soc. 131 (2009) 8348-8349. [PMID: 19489556]

4. Benjdia, A., Subramanian, S., Leprince, J., Vaudry, H., Johnson, M.K. and Berteau, O. Anaerobic sulfatase-maturating enzyme - a mechanistic link with glycyl radical-activating enzymes. FEBS J. 277 (2010) 1906-1920. [PMID: 20218986]

5. Grove, T.L., Ahlum, J.H., Qin, R.M., Lanz, N.D., Radle, M.I., Krebs, C. and Booker, S.J. Further characterization of Cys-type and Ser-type anaerobic sulfatase maturating enzymes suggests a commonality in the mechanism of catalysis. Biochemistry 52 (2013) 2874-2887. [PMID: 23477283]

[EC 1.8.98.7 created 2020]


EC 1.8.99 With unnown physiological acceptors

Contents

EC 1.8.99.1 deleted now covered by EC 1.8.1.2 and EC 1.8.7.1
EC 1.8.99.2 adenylyl-sulfate reductase
EC 1.8.99.3 deleted
EC 1.8.99.4 deleted, now EC 1.8.4.8, phosphoadenylyl-sulfate reductase (thioredoxin)

EC 1.8.99.5 dissimilatory sulfite reductase


[EC 1.8.99.1 Deleted entry: sulfite reductase. Now covered by EC 1.8.1.2, assimilatory sulfite reductase (NADPH) and EC 1.8.7.1, assimilatory sulfite reductase (ferredoxin). (EC 1.8.99.1 created 1972, deleted 2015)]

EC 1.8.99.2

Accepted name: adenylyl-sulfate reductase

Reaction: AMP + sulfite + acceptor = adenylyl sulfate + reduced acceptor

Other name(s): adenosine phosphosulfate reductase; adenosine 5'-phosphosulfate reductase; APS-reductase; APS reductase; AMP,sulfite:(acceptor) oxidoreductase (adenosine-5'-phosphosulfate-forming)

Systematic name: AMP,sulfite:acceptor oxidoreductase (adenosine-5'-phosphosulfate-forming)

Comments: An iron flavoprotein (FAD). Methyl viologen can act as acceptor.

Links to other databases: BRENDA, EXPASY, KEGG, Metacyc, PDB, CAS registry number: 9027-75-2

References:

1. Michaels, G.B., Davidson, J.T. and Peck, H.D.,Jr. A flavin-sulfite adduct as an intermediate in the reaction catalyzed by adenylyl sulfate reductase from Desulfovibrio vulgaris. Biochem. Biophys. Res. Commun. 39 (1970) 321-328. [PMID: 5421934]

[EC 1.8.99.2 created 1972]

[EC 1.8.99.3 Deleted entry: hydrogensulfite reductase, now known to be an in vitro artifact of EC 1.8.99.5, dissimilatory sulfite reductase (EC 1.8.99.3 created 1986, deleted 2016)]

[EC 1.8.99.4 Transferred entry: Now EC 1.8.4.8, phosphoadenylyl-sulfate reductase (thioredoxin) (EC 1.8.99.4 created 1999, deleted 2000)]

[EC 1.8.99.5 Transferred entry: dissimilatory sulfite reductase. Now classified as EC 1.8.1.22, dissimilatory sulfite reductase system. (EC 1.8.99.5 created 2015, deleted 2023)]


Continued with EC 1.9 to EC 1.12
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