An asterisk before 'EC' indicates that this is an amendment to an existing enzyme rather than a new enzyme entry.
See also entries in separate files for EC 2, EC 3 and EC 4 to EC 6.
Common name: 4-hydroxythreonine-4-phosphate dehydrogenase
Reaction: 4-(phosphonooxy)-L-threonine + NAD+ = (2S)-2-amino-3-oxo-4-phosphonooxybutanoate + NADH + H+
For diagram, click here
Other name(s): NAD+-dependent threonine 4-phosphate dehydrogenase; L-threonine 4-phosphate dehydrogenase; 4-(phosphohydroxy)-L-threonine dehydrogenase; PdxA
Systematic name: 4-(phosphonooxy)-L-threonine:NAD+ oxidoreductase
Comments: The product of the reaction undergoes decarboxylation to give 3-amino-2-oxopropyl phosphate. In Escherichia coli, the coenzyme pyridoxal 5'-phosphate is synthesized de novo by a pathway that involves EC 1.2.1.72 (erythrose-4-phosphate dehydrogenase), EC 1.1.1.290 (4-phosphoerythronate dehydrogenase), EC 2.6.1.52 (phosphoserine transaminase), EC 1.1.1.262 (4-hydroxythreonine-4-phosphate dehydrogenase), EC 2.6.99.2 (pyridoxine 5'-phosphate synthase) and EC 1.4.3.5 (with pyridoxine 5'-phosphate as substrate).
Links to other databases: BRENDA, ERGO, EXPASY, KEGG, PDB
CAS registry number:
References:
1. Cane, D.E., Hsiung, Y., Cornish, J.A., Robinson, J.K and Spenser, I.D. Biosynthesis of vitamine B6: The oxidation of L-threonine 4-phosphate by PdxA. J. Am. Chem. Soc. 120 (1998) 1936-1937.
2. Laber, B., Maurer, W., Scharf, S., Stepusin, K. and Schmidt, F.S. Vitamin B6 biosynthesis: formation of pyridoxine 5'-phosphate from 4-(phosphohydroxy)-L-threonine and 1-deoxy-D-xylulose-5-phosphate by PdxA and PdxJ protein. FEBS Lett. 449 (1999) 45-48. [PMID: 10225425]
3. Sivaraman, J., Li, Y., Banks, J., Cane, D.E., Matte, A. and Cygler, M. Crystal structure of Escherichia coli PdxA, an enzyme involved in the pyridoxal phosphate biosynthesis pathway. J. Biol. Chem. 278 (2003) 43682-43690. [PMID: 12896974]
Common name: sorbose reductase
Reaction: D-glucitol + NADP+ = L-sorbose + NADPH + H+
For diagram, click here
Glossary: L-sorbose = L-xylo-hex-2-ulose
Other name(s): Sou1p
Systematic name: D-glucitol:NADP+ oxidoreductase
Comments: The reaction occurs predominantly in the reverse direction. This enzyme can also convert D-fructose into D-mannitol, but more slowly. Belongs in the short-chain dehydrogenase family.
Links to other databases: BRENDA, ERGO, EXPASY, KEGG, CAS registry number:
References:
1. Greenberg, J.R., Price, N.P., Oliver, R.P., Sherman, F. and Rustchenko, E. Candida albicans SOU1 encodes a sorbose reductase required for L-sorbose utilization. Yeast 22 (2005) 957-969. [PMID: 16134116]
2. Sugisawa, T., Hoshino, T. and Fujiwara, A. Purification and properties of NADPH-linked L-sorbose reductase from Gluconobacter melanogenus N44-1. Agric. Biol. Chem. 55 (1991) 2043-2049.
3. Shinjoh, M., Tazoe, M. and Hoshino, T. NADPH-dependent L-sorbose reductase is responsible for L-sorbose assimilation in Luconobacter suboxydans IFO 3291. J. Bacteriol. 184 (2002) 861-863. [PMID: 11790761]
Common name: 4-phosphoerythronate dehydogenase
Reaction: 4-phospho-D-erythronate + NAD+ = (3R)-3-hydroxy-2-oxo-4-phosphonooxybutanoate + NADH + H+
For diagram, click here
Other name(s): PdxB; PdxB 4PE dehydrogenase; 4-O-phosphoerythronate dehydrogenase
Systematic name: 4-phospho-D-erythronate:NAD+ 2-oxidoreductase
Comments: This enzyme catalyses the second step in the biosynthesis of the coenzyme pyridoxal 5'-phosphate in Escherichia coli. The reaction occurs predominantly in the reverse direction [3]. Other enzymes involved in this pathway are EC 1.2.1.72 (erythrose-4-phosphate dehydrogenase), EC 1.1.1.262 (4-hydroxythreonine-4-phosphate dehydrogenase), EC 2.6.99.2 (pyridoxine 5'-phosphate synthase) and EC 1.4.3.5 (pyridoxamine-phosphate oxidase).
Links to other databases: BRENDA, ERGO, EXPASY, KEGG, CAS registry number:
References:
1. Lam, H.M. and Winkler, M.E. Metabolic relationships between pyridoxine (vitamin B6) and serine biosynthesis in Escherichia coli K-12. J. Bacteriol. 172 (1990) 6518-6528. [PMID: 2121717]
2. Pease, A.J., Roa, B.R., Luo, W. and Winkler, M.E. Positive growth rate-dependent regulation of the pdxA, ksgA, and pdxB genes of Escherichia coli K-12. J. Bacteriol. 184 (2002) 1359-1369. [PMID: 11844765]
3. Zhao, G. and Winkler, M.E. A novel α-ketoglutarate reductase activity of the serA-encoded 3-phosphoglycerate dehydrogenase of Escherichia coli K-12 and its possible implications for human 2-hydroxyglutaric aciduria. J. Bacteriol. 178 (1996) 232-239. [PMID: 8550422]
4. Grant, G.A. A new family of 2-hydroxyacid dehydrogenases. Biochem. Biophys. Res. Commun. 165 (1989) 1371-1374. [PMID: 2692566]
5. Schoenlein, P.V., Roa, B.B. and Winkler, M.E. Divergent transcription of pdxB and homology between the pdxB and serA gene products in Escherichia coli K-12. J. Bacteriol. 171 (1989) 6084-6092. [PMID: 2681152]
[EC 1.1.99.19 Deleted entry: uracil dehydrogenase. Now EC 1.17.99.4, uracil/thymine dehydrogenase (EC 1.1.99.19 created 1961 as EC 1.2.99.1, transferred 1984 to EC 1.1.99.19, deleted 2006)]
Common name: acetaldehyde dehydrogenase (acetylating)
Reaction: acetaldehyde + CoA + NAD+ = acetyl-CoA + NADH + H+
Other name(s): aldehyde dehydrogenase (acylating); ADA; acylating acetaldehyde dehyrogenase; DmpF
Systematic name: acetaldehyde:NAD+ oxidoreductase (CoA-acetylating)
Comments: Also acts, more slowly, on glycolaldehyde, propanal and butanal. In Pseudomonas species, this enzyme forms part of a bifunctional enzyme with EC 4.1.3.39, 4-hydroxy-2-oxovalerate aldolase. It is the final enzyme in the meta-cleavage pathway for the degradation of phenols, cresols and catechol, converting the acetaldehyde produced by EC 4.1.3.39 into acetyl-CoA [3]. NADP+ can replace NAD+ but the rate of reaction is much slower [3].
Links to other databases: BRENDA, ERGO, EXPASY, GTD, KEGG, CAS registry number: 9028-91-5
References:
1. Burton, R.M. and Stadtman, E.R. The oxidation of acetaldehyde to acetyl coenzyme A. J. Biol. Chem. 202 (1953) 873-890.
2. Smith, L.T. and Kaplan, N.O. Purification, properties, and kinetic mechanism of coenzyme A-linked aldehyde dehydrogenase from Clostridium kluyveri. Arch. Biochem. Biophys. 203 (1980) 663-675. [PMID: 7458347]
3. Powlowski, J., Sahlman, L. and Shingler, V. Purification and properties of the physically associated meta-cleavage pathway enzymes 4-hydroxy-2-ketovalerate aldolase and aldehyde dehydrogenase (acylating) from Pseudomonas sp. strain CF600. J. Bacteriol. 175 (1993) 377-385. [PMID: 8419288]
Common name: succinylglutamate-semialdehyde dehydrogenase
Reaction: N-succinyl-L-glutamate 5-semialdehyde + NAD+ + H2O = N-succinyl-L-glutamate + NADH + 2 H+
For diagram, click here
Other name(s): succinylglutamic semialdehyde dehydrogenase; N-succinylglutamate 5-semialdehyde dehydrogenase; SGSD; AruD; AstD
Systematic name: N-succinyl-L-glutamate 5-semialdehyde:NAD+ oxidoreductase
Comments: This is the fourth enzyme in the arginine succinyltransferase (AST) pathway for the catabolism of arginine [1]. This pathway converts the carbon skeleton of arginine into glutamate, with the concomitant production of ammonia and conversion of succinyl-CoA into succinate and CoA. The five enzymes involved in this pathway are EC 2.3.1.109 (arginine N-succinyltransferase), EC 3.5.3.23 (N-succinylarginine dihydrolase), EC 2.6.1.11 (acetylornithine transaminase), EC 1.2.1.71 (succinylglutamate-semialdehyde dehydrogenase) and EC 3.5.1.96 (succinylglutamate desuccinylase) [3,6].
Links to other databases: BRENDA, ERGO, EXPASY, KEGG, CAS registry number:
References:
1. Vander Wauven, C., Jann, A., Haas, D., Leisinger, T. and Stalon, V. N2-succinylornithine in ornithine catabolism of Pseudomonas aeruginosa. Arch. Microbiol. 150 (1988) 400-404. [PMID: 3144259]
2. Vander Wauven, C. and Stalon, V. Occurrence of succinyl derivatives in the catabolism of arginine in Pseudomonas cepacia. J. Bacteriol. 164 (1985) 882-886. [PMID: 2865249]
3. Tricot, C., Vander Wauven, C., Wattiez, R., Falmagne, P. and Stalon, V. Purification and properties of a succinyltransferase from Pseudomonas aeruginosa specific for both arginine and ornithine. Eur. J. Biochem. 224 (1994) 853-861. [PMID: 7523119]
4. Itoh, Y. Cloning and characterization of the aru genes encoding enzymes of the catabolic arginine succinyltransferase pathway in Pseudomonas aeruginosa. J. Bacteriol. 179 (1997) 7280-7290. [PMID: 9393691]
5. Schneider, B.L., Kiupakis, A.K. and Reitzer, L.J. Arginine catabolism and the arginine succinyltransferase pathway in Escherichia coli. J. Bacteriol. 180 (1998) 4278-4286. [PMID: 9696779]
6. Cunin, R., Glansdorff, N., Pierard, A. and Stalon, V. Biosynthesis and metabolism of arginine in bacteria. Microbiol. Rev. 50 (1986) 314-352. [PMID: 3534538]
Common name: erythrose-4-phosphate dehydrogenase
Reaction: D-erythrose 4-phosphate + NAD+ + H2O = 4-phosphoerythronate + NADH + 2 H+
For diagram, click here
Other name(s): erythrose 4-phosphate dehydrogenase; E4PDH; GapB; Epd dehydrogenase; E4P dehydrogenase
Systematic name: D-erythrose 4-phosphate:NAD+ oxidoreductase
Comments: This enzyme was originally thought to be a glyceraldehyde-3-phosphate dehydrogenase (EC 1.2.1.12), but this has since been disproved, as glyceraldehyde 3-phosphate is not a substrate [1,2]. Forms part of the pyridoxal-5'-phosphate coenzyme biosynthesis pathway in Escherichia coli, along with EC 1.1.1.290 (4-phosphoerythronate dehydrogenase), EC 2.6.1.52 (phosphoserine transaminase), EC 1.1.1.262 (4-hydroxythreonine-4-phosphate dehydrogenase), EC 2.6.99.2 (pyridoxine 5'-phosphate synthase) and EC 1.4.3.5 (pyridoxamine-phosphate oxidase).
Links to other databases: BRENDA, ERGO, EXPASY, KEGG, CAS registry number:
References:
1. Zhao, G., Pease, A.J., Bharani, N. and Winkler, M.E. Biochemical characterization of gapB-encoded erythrose 4-phosphate dehydrogenase of Escherichia coli K-12 and its possible role in pyridoxal 5'-phosphate biosynthesis. J. Bacteriol. 177 (1995) 2804-2812. [PMID: 7751290]
2. Boschi-Muller, S., Azza, S., Pollastro, D., Corbier, C. and Branlant, G. Comparative enzymatic properties of GapB-encoded erythrose-4-phosphate dehydrogenase of Escherichia coli and phosphorylating glyceraldehyde-3-phosphate dehydrogenase. J. Biol. Chem. 272 (1997) 15106-15112. [PMID: 9182530]
3. Yang, Y., Zhao, G., Man, T.K. and Winkler, M.E. Involvement of the gapA- and epd (gapB)-encoded dehydrogenases in pyridoxal 5'-phosphate coenzyme biosynthesis in Escherichia coli K-12. J. Bacteriol. 180 (1998) 4294-4299. [PMID: 9696782]
[EC 1.2.99.1 Transferred entry: now EC 1.17.99.4, uracil/thymine dehydrogenase (EC 1.2.99.1 created 1961, deleted 1984)]
Common name: quinoline-4-carboxylate 2-oxidoreductase
Reaction: quinoline-4-carboxylate + acceptor + H2O = 2-oxo-1,2-dihydroquinoline-4-carboxylate + reduced acceptor
For diagram, BRENDA, ERGO, EXPASY, KEGG, CAS registry number: 175780-18-4
References:
1. Bauer, G. and Lingens, F. Microbial metabolism of quinoline and related compounds. XV. Quinoline-4-carboxylic acid oxidoreductase from Agrobacterium spec.1B: a molybdenum-containing enzyme. Biol. Chem. Hoppe-Seyler 373 (1992) 699-705. [PMID: 1418685]
[EC 1.4.1.22 Deleted entry: ornithine cyclodeaminase. It was pointed out during the public-review process that there is no overall consumption of NAD+ during the reaction. As a result, transfer of the enzyme from EC 4.3.1.12 was not necessary and EC 1.4.1.22 was withdrawn before being made official. (EC 1.4.1.22 created 2006, deleted 2006)]
Common name: pyridoxal 5'-phosphate synthase
Reaction: (1) pyridoxamine 5'-phosphate + H2O + O2 = pyridoxal 5'-phosphate + NH3 + H2O2
(2) pyridoxine 5'-phosphate + O2 = pyridoxal 5'-phosphate + H2O2
For diagram, click here
Other name(s): pyridoxamine 5'-phosphate oxidase; pyridoxamine phosphate oxidase; pyridoxine (pyridoxamine)phosphate oxidase; pyridoxine (pyridoxamine) 5'-phosphate oxidase; pyridoxaminephosphate oxidase (EC 1.4.3.5: deaminating); PMP oxidase; pyridoxol-5'-phosphate:oxygen oxidoreductase (deaminating) (incorrect); pyridoxamine-phosphate oxidase; PdxH
Systematic name: pyridoxamine-5'-phosphate:oxygen oxidoreductase (deaminating)
Comments: A flavoprotein (FMN). In Escherichia coli, the coenzyme pyridoxal 5'-phosphate is synthesized de novo by a pathway that involves EC 1.2.1.72 (erythrose-4-phosphate dehydrogenase), EC 1.1.1.290 (4-phosphoerythronate dehydrogenase), EC 2.6.1.52 (phosphoserine transaminase), EC 1.1.1.262 (4-hydroxythreonine-4-phosphate dehydrogenase), EC 2.6.99.2 (pyridoxine 5'-phosphate synthase) and EC 1.4.3.5 (with pyridoxine 5'-phosphate as substrate).
Links to other databases: BRENDA, ERGO, EXPASY, KEGG, PDB, CAS registry number: 9029-21-4
References:
1. Choi, J.-D., Bowers-Komro, D.M., Davis, M.D., Edmondson, D.E. and McCormick, D.B. Kinetic properties of pyridoxamine (pyridoxine)-5'-phosphate oxidase from rabbit liver. J. Biol. Chem. 258 (1983) 840-845. [PMID: 6822512]
2. Wada, H. and Snell, E.E. The enzymatic oxidation of pyridoxine and pyridoxamine phosphates. J. Biol. Chem. 236 (1961) 2089-2095. [PMID: 13782387]
3. Notheis, C., Drewke, C. and Leistner, E. Purification and characterization of the pyridoxol-5'-phosphate:oxygen oxidoreductase (deaminating) from Escherichia coli. Biochim. Biophys. Acta 1247 (1995) 265-271. [PMID: 7696318]
4. Laber, B., Maurer, W., Scharf, S., Stepusin, K. and Schmidt, F.S. Vitamin B6 biosynthesis: formation of pyridoxine 5'-phosphate from 4-(phosphohydroxy)-L-threonine and 1-deoxy-D-xylulose-5-phosphate by PdxA and PdxJ protein. FEBS Lett. 449 (1999) 45-48. [PMID: 10225425]
5. Musayev, F.N., Di Salvo, M.L., Ko, T.P., Schirch, V. and Safo, M.K. Structure and properties of recombinant human pyridoxine 5'-phosphate oxidase. Protein Sci. 12 (2003) 1455-1463. [PMID: 12824491]
6. Safo, M.K., Musayev, F.N. and Schirch, V. Structure of Escherichia coli pyridoxine 5'-phosphate oxidase in a tetragonal crystal form: insights into the mechanistic pathway of the enzyme. Acta Crystallogr. D Biol. Crystallogr. 61 (2005) 599-604. [PMID: 15858270]
Common name: glycine dehydrogenase (decarboxylating)
Reaction: glycine + H-protein-lipoyllysine = H-protein-S-aminomethyldihydrolipoyllysine + CO2
For diagram, click here
Glossary: dihydrolipoyl group
Other name(s): P-protein; glycine decarboxylase; glycine-cleavage complex; glycine:lipoylprotein oxidoreductase (decarboxylating and acceptor-aminomethylating); protein P1
Systematic name: glycine:H-protein-lipoyllysine oxidoreductase (decarboxylating, acceptor-amino-methylating)
Comments: A pyridoxal-phosphate protein. A component, with EC 2.1.2.10, aminomethyltransferase and EC 1.8.1.4, dihydrolipoyl dehydrogenanse, of the glycine cleavage system, previously known as glycine synthase. 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 [3].
Links to other databases: BRENDA, ERGO, EXPASY, KEGG, CAS registry number: 37259-67-9
References:
1. Hiraga, K. and Kikuchi, G. The mitochondrial glycine cleavage system. Functional association of glycine decarboxylase and aminomethyl carrier protein. J. Biol. Chem. 255 (1980) 11671-11676. [PMID: 7440563]
2. 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]
3. 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]
Common name: preQ1 synthase
Reaction: preQ1 + 2 NADP+ = 7-cyano-7-carbaguanine + 2 NADPH
Glossary: preQ1 = 7-aminomethyl-7-carbaguanine
Other name(s): YkvM; QueF; preQ0 reductase; preQ0 oxidoreductase; 7-cyano-7-deazaguanine reductase; 7-aminomethyl-7-carbaguanine:NADP+ oxidoreductase
Systematic name: preQ1: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, queuine tRNA-ribosyltransferase. Queosine 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, ERGO, EXPASY, KEGG, CAS registry number:
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.
Common 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, ERGO, EXPASY, KEGG, 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]
Common name: lignin peroxidase
Reaction: 1,2-bis(3,4-dimethoxyphenyl)propane-1,3-diol + H2O2 = 3,4-dimethoxybenzaldehyde + 1-(3,4-dimethoxyphenyl)ethane-1,2-diol + H2O
For diagram, click here
Other name(s): diarylpropane oxygenase; ligninase I; diarylpropane peroxidase; LiP; diarylpropane:oxygen,hydrogen-peroxide oxidoreductase; 1,2-bis(3,4-dimethoxyphenyl)propane-1,3-diol:hydrogen-peroxide oxidoreductase (C-C-bond-cleaving)
Systematic name: 1,2-bis(3,4-dimethoxyphenyl)propane-1,3-diol:hydrogen-peroxide oxidoreductase
Comments: A hemoprotein. Brings about the oxidative cleavage of C-C bonds and ether (C-O-C) bonds in a number of lignin model compounds (of the diarylpropane and arylpropane-aryl ether type). The enzyme also oxidizes benzyl alcohols to aldehydes, via an aromatic cation radical [9]. Involved in the oxidative breakdown of lignin in white rot basidiomycetes. Molecular oxygen may be involved in the reaction of substrate radicals under aerobic conditions [3,8].
Links to other databases: BRENDA, ERGO, EXPASY, KEGG, PDB, CAS registry number: 93792-13-3
References:
1. Paszczynski, A., Huynh, V.-B. and Crawford, R. Comparison of ligninase-I and peroxidase-M2 from the white-rot fungus Phanerochaete chrysosporium. Arch. Biochem. Biophys. 244 (1986) 750-765. [PMID: 3080953]
2. Renganathan, V., Miki, K. and Gold, M.H. Multiple molecular forms of diarylpropane oxygenase, an H2O2-requiring, lignin-degrading enzyme from Phanerochaete chrysosporium. Arch. Biochem. Biophys. 241 (1985) 304-314. [PMID: 4026322]
3. Tien, M. and Kirk, T.T. Lignin-degrading enzyme from Phanerochaete chrysosporium; purification, characterization, and catalytic properties of a unique H2O2-requiring oxygenase. Proc. Natl. Acad. Sci. USA 81 (1984) 2280-2284.
4. Doyle, W.A., Blodig, W., Veitch, N.C., Piontek, K. and Smith, A.T. Two substrate interaction sites in lignin peroxidase revealed by site-directed mutagenesis. Biochemistry 37 (1998) 15097-15105. [PMID: 9790672]
5. Wariishi, H., Marquez, L., Dunford, H.B. and Gold, M.H. Lignin peroxidase compounds II and III. Spectral and kinetic characterization of reactions with peroxides. J. Biol. Chem. 265 (1990) 11137-11142. [PMID: 2162833]
6. Cai, D.Y. and Tien, M. Characterization of the oxycomplex of lignin peroxidases from Phanerochaete chrysosporium: equilibrium and kinetics studies. Biochemistry 29 (1990) 2085-2091. [PMID: 2328240]
7. Tien, M. and Tu, C.P. Cloning and sequencing of a cDNA for a ligninase from Phanerochaete chrysosporium. Nature 326 (1987) 520-523. [PMID: 3561490]
8. Renganathan, V., Miki, K. and Gold, M.H. Role of molecular oxygen in lignin peroxidase reactions. Arch. Biochem. Biophys. 246 (1986) 155-161. [PMID: 3754412]
9. Kersten, P.J., Tien, M., Kalyanaraman, B. and Kirk, T.K. The ligninase of Phanerochaete chrysosporium generates cation radicals from methoxybenzenes. J. Biol. Chem. 260 (1985) 2609-2612. [PMID: 2982828]
10. Kirk, T.K. and Farrell, R.L. Enzymatic "combustion": the microbial degradation of lignin. Annu. Rev. Microbiol. 41 (1987) 465-505. [PMID: 3318677]
Common name: versatile peroxidase
Reaction: (1) Reactive Black 5 + H2O2 = oxidized Reactive Black 5 + 2 H2O
(2) donor + H2O2 = oxidized donor + 2 H2O
Glossary: reactive black 5 = tetrasodium 4-amino-5-hydroxy-3,6(bis(4-(2-(sulfonatooxy)ethylsulfonyl)phenyl)azo)-naphthalene-2,7-disulfonate
Other name(s): VP; hybrid peroxidase; polyvalent peroxidase
Systematic name: reactive-black-5:hydrogen-peroxide oxidoreductase
Comments: A hemoprotein. This ligninolytic peroxidase combines the substrate-specificity characteristics of the two other ligninolytic peroxidases, EC 1.11.1.13, manganese peroxidase and EC 1.11.1.14, lignin peroxidase. It is also able to oxidize phenols, hydroquinones and both low- and high-redox-potential dyes, due to a hybrid molecular architecture that involves multiple binding sites for substrates [2,4].
Links to other databases: BRENDA, ERGO, EXPASY, KEGG, PDB, CAS registry number:
References:
1. Martínez, M.J., Ruiz-Dueñas, F.J., Guillén, F. and Martínez, A.T. Purification and catalytic properties of two manganese peroxidase isoenzymes from Pleurotus eryngii. Eur. J. Biochem. 237 (1996) 424-432. [PMID: 8647081]
2. Heinfling, A., Ruiz-Dueñas, F.J., Martínez, M.J., Bergbauer, M., Szewzyk, U. and Martínez, A.T. A study on reducing substrates of manganese-oxidizing peroxidases from Pleurotus eryngii and Bjerkandera adusta. FEBS Lett. 428 (1998) 141-146. [PMID: 9654123]
3. Ruiz-Due̱as, F.J., Martínez, M.J. and Martínez, A.T. Molecular characterization of a novel peroxidase isolated from the ligninolytic fungus Pleurotus eryngii. Mol. Microbiol. 31 (1999) 223-235. [PMID: 9987124]
4. Camarero, S., Sarkar, S., Ruiz-Dueñas, F.J., Martínez, M.J. and Martínez, A.T. Description of a versatile peroxidase involved in the natural degradation of lignin that has both manganese peroxidase and lignin peroxidase substrate interaction sites. J. Biol. Chem. 274 (1999) 10324-10330. [PMID: 10187820]
5. Ruiz-Dueñas, F.J., Martínez, M.J. and Martínez, A.T. Heterologous expression of Pleurotus eryngii peroxidase confirms its ability to oxidize Mn2+ and different aromatic substrates. Appl. Environ. Microbiol. 65 (1999) 4705-4707. [PMID: 10508113]
6. Camarero, S., Ruiz-Dueñas, F.J., Sarkar, S., Martínez, M.J. and Martínez, A.T. The cloning of a new peroxidase found in lignocellulose cultures of Pleurotus eryngii and sequence comparison with other fungal peroxidases. FEMS Microbiol. Lett. 191 (2000) 37-43. [PMID: 11004397]
7. Ruiz-Dueñas, F.J., Camarero, S., Pérez-Boada, M., Martínez, M.J. and Martínez, A.T. A new versatile peroxidase from Pleurotus. Biochem. Soc. Trans. 29 (2001) 116-122. [PMID: 11356138]
8. Banci, L., Camarero, S., Martínez, A.T., Martínez, M.J., Pérez-Boada, M., Pierattelli, R. and Ruiz-Dueñas, F.J. NMR study of manganese(II) binding by a new versatile peroxidase from the white-rot fungus Pleurotus eryngii. J. Biol. Inorg. Chem. 8 (2003) 751-760. [PMID: 12884090]
9. Pérez-Boada, M., Ruiz-Dueñas, F.J., Pogni, R., Basosi, R., Choinowski, T., Martínez, M.J., Piontek, K. and Martínez, A.T. Versatile peroxidase oxidation of high redox potential aromatic compounds: site-directed mutagenesis, spectroscopic and crystallographic investigation of three long-range electron transfer pathways. J. Mol. Biol. 354 (2005) 385-402. [PMID: 16246366]
Common name: tryptophan 2,3-dioxygenase
Reaction: L-tryptophan + O2 = N-formyl-L-kynurenine
For diagram, click here
Other name(s): tryptophan pyrrolase (ambiguous); tryptophanase; tryptophan oxygenase; tryptamine 2,3-dioxygenase; tryptophan peroxidase; indoleamine 2,3-dioxygenase (ambiguous); indolamine 2,3-dioxygenase (ambiguous); L-tryptophan pyrrolase; TDO; L-tryptophan 2,3-dioxygenase
Systematic name: L-tryptophan:oxygen 2,3-oxidoreductase (decyclizing)
Comments: A protohemoprotein. In mammals, the enzyme appears to be located only in the liver. This enzyme, together with EC 1.13.11.52, indoleamine 2,3-dioxygenase, catalyses the first and rate-limiting step in the kynurenine pathway, the major pathway of tryptophan metabolism [5]. The enzyme is specific for tryptophan as substrate, but is far more active with L-tryptophan than with D-tryptophan [2].
Links to other databases: BRENDA, ERGO, EXPASY, KEGG, CAS registry number: 9014-51-1
References:
1. Uchida, K., Shimizu, T., Makino, R., Sakaguchi, K., Iizuka, T., Ishimura, Y., Nozawa, T. and Hatano, M. Magnetic and natural circular dichroism of L-tryptophan 2,3-dioxygenases and indoleamine 2,3-dioxygenase. I. Spectra of ferric and ferrous high spin forms. J. Biol. Chem. 258 (1983) 2519-2525. [PMID: 6600455]
2. Ren, S., Liu, H., Licad, E. and Correia, M.A. Expression of rat liver tryptophan 2,3-dioxygenase in Escherichia coli: structural and functional characterization of the purified enzyme. Arch. Biochem. Biophys. 333 (1996) 96-102. [PMID: 8806758]
3. Leeds, J.M., Brown, P.J., McGeehan, G.M., Brown, F.K. and Wiseman, J.S. Isotope effects and alternative substrate reactivities for tryptophan 2,3-dioxygenase. J. Biol. Chem. 268 (1993) 17781-17786. [PMID: 8349662]
4. Dang, Y., Dale, W.E. and Brown, O.R. Comparative effects of oxygen on indoleamine 2,3-dioxygenase and tryptophan 2,3-dioxygenase of the kynurenine pathway. Free Radic. Biol. Med. 28 (2000) 615-624. [PMID: 10719243]
5. Littlejohn, T.K., Takikawa, O., Truscott, R.J. and Walker, M.J. Asp274 and His346 are essential for heme binding and catalytic function of human indoleamine 2,3-dioxygenase. J. Biol. Chem. 278 (2003) 29525-29531. [PMID: 12766158]
Common name: cysteamine dioxygenase
Reaction: 2-aminoethanethiol + O2 = hypotaurine
For diagram, click here
Other name(s): persulfurase; cysteamine oxygenase; cysteamine:oxygen oxidoreductase
Systematic name: 2-aminoethanethiol:oxygen oxidoreductase
Comments: A non-heme iron protein that is involved in the biosynthesis of taurine. Requires catalytic amounts of a cofactor-like compound, such as sulfur, sufide, selenium or methylene blue for maximal activity. 3-Aminopropanethiol (homocysteamine) and 2-mercaptoethanol can also act as substrates, but glutathione, cysteine, and cysteine ethyl- and methyl esters are not good substrates [1,3].
Links to other databases: BRENDA, ERGO, EXPASY, KEGG, CAS registry number: 9033-41-4
References:
1. Cavallini, D., de Marco, C., Scandurra, R., Duprè, S. and Graziani, M.T. The enzymatic oxidation of cysteamine to hypotaurine. Purification and properties of the enzyme. J. Biol. Chem. 241 (1966) 3189-3196. [PMID: 5912113]
2. Wood, J.L. and Cavallini, D. Enzymic oxidation of cysteamine to hypotaurine in the absence of a cofactor. Arch. Biochem. Biophys. 119 (1967) 368-372. [PMID: 6052430]
3. Cavallini, D., Federici, G., Ricci, G., Duprè, S. and Antonucci, A. The specificity of cysteamine oxygenase. FEBS Lett. 56 (1975) 348-351. [PMID: 1157952]
4. Richerson, R.B. and Ziegler, D.M. Cysteamine dioxygenase. Methods Enzymol. 143 (1987) 410-415. [PMID: 3657558]
[EC 1.13.11.42 Deleted entry: indoleamine-pyrrole 2,3-dioxygenase (EC 1.13.11.42 created 1992, deleted 2006)]
Common name: indoleamine 2,3-dioxygenase
Reaction: (1) D-tryptophan + O2 = N-formyl-D-kynurenine
(2) L-tryptophan + O2 = N-formyl-L-kynurenine
For diagram, click here
Other name(s): IDO (ambiguous); tryptophan pyrrolase (ambiguous)
Systematic name: D-tryptophan:oxygen 2,3-oxidoreductase (decyclizing)
Comments: A protohemoprotein. Requires ascorbic acid and methylene blue for activity. This enzyme has broader substrate specificity than EC 1.13.11.11, tryptophan 2,3-dioxygenase [1]. It is induced in response to pathological conditions and host-defense mechanisms and its distribution in mammals is not confined to the liver [2]. While the enzyme is more active with D-tryptophan than L-tryptophan, its only known function to date is in the metabolism of L-tryptophan [2,6]. Superoxide radicals can replace O2 as oxygen donor [4,7].
Links to other databases: BRENDA, ERGO, EXPASY, KEGG, CAS registry number:
References:
1. Yamamoto, S. and Hayaishi, O. Tryptophan pyrrolase of rabbit intestine. D- and L-tryptophan-cleaving enzyme or enzymes. J. Biol. Chem. 242 (1967) 5260-5266. [PMID: 6065097]
2. Yasui, H., Takai, K., Yoshida, R. and Hayaishi, O. Interferon enhances tryptophan metabolism by inducing pulmonary indoleamine 2,3-dioxygenase: its possible occurrence in cancer patients. Proc. Natl. Acad. Sci. USA 83 (1986) 6622-6626. [PMID: 2428037]
3. Takikawa, O., Yoshida, R., Kido, R. and Hayaishi, O. Tryptophan degradation in mice initiated by indoleamine 2,3-dioxygenase. J. Biol. Chem. 261 (1986) 3648-3653. [PMID: 2419335]
4. Hirata, F., Ohnishi, T. and Hayaishi, O. Indoleamine 2,3-dioxygenase. Characterization and properties of enzyme. O2- complex. J. Biol. Chem. 252 (1977) 4637-4642. [PMID: 194886]
5. Dang, Y., Dale, W.E. and Brown, O.R. Comparative effects of oxygen on indoleamine 2,3-dioxygenase and tryptophan 2,3-dioxygenase of the kynurenine pathway. Free Radic. Biol. Med. 28 (2000) 615-624. [PMID: 10719243]
6. Littlejohn, T.K., Takikawa, O., Truscott, R.J. and Walker, M.J. Asp274 and His346 are essential for heme binding and catalytic function of human indoleamine 2,3-dioxygenase. J. Biol. Chem. 278 (2003) 29525-29531. [PMID: 12766158]
7. Thomas, S.R. and Stocker, R. Redox reactions related to indoleamine 2,3-dioxygenase and tryptophan metabolism along the kynurenine pathway. Redox Rep. 4 (1999) 199-220. [PMID: 10731095]
8. Sono, M. Spectroscopic and equilibrium studies of ligand and organic substrate binding to indolamine 2,3-dioxygenase. Biochemistry 29 (1990) 1451-1460. [PMID: 2334706]
Common name: acireductone dioxygenase (Ni2+-requiring)
Reaction: 1,2-dihydroxy-5-(methylthio)pent-1-en-3-one + O2 = 3-(methylthio)propanoate + formate + CO
For diagram, click here
Other name(s): ARD; 2-hydroxy-3-keto-5-thiomethylpent-1-ene dioxygenase (ambiguous); acireductone dioxygenase (ambiguous); E-2
Systematic name: 1,2-dihydroxy-5-(methylthio)pent-1-en-3-one:oxygen oxidoreductase (formate- and CO-forming)
Comments: Requires Ni2+. If iron(II) is bound instead of Ni2+, the reaction catalysed by EC 1.13.11.54, acireductone dioxygenase [iron(II)-requiring], occurs instead [1]. The enzyme from Klebsiella oxytoca (formerly Klebsiella pneumoniae) ATCC strain 8724 is involved in the methionine salvage pathway.
Links to other databases: BRENDA, ERGO, EXPASY, KEGG, CAS registry number:
References:
1. Wray, J.W. and Abeles, R.H. A bacterial enzyme that catalyzes formation of carbon monoxide. J. Biol. Chem. 268 (1993) 21466-21469. [PMID: 8407993]
2. Wray, J.W. and Abeles, R.H. The methionine salvage pathway in Klebsiella pneumoniae and rat liver. Identification and characterization of two novel dioxygenases. J. Biol. Chem. 270 (1995) 3147-3153. [PMID: 7852397]
3. Furfine, E.S. and Abeles, R.H. Intermediates in the conversion of 5'-S-methylthioadenosine to methionine in Klebsiella pneumoniae. J. Biol. Chem. 263 (1988) 9598-9606. [PMID: 2838472]
4. Dai, Y., Wensink, P.C. and Abeles, R.H. One protein, two enzymes. J. Biol. Chem. 274 (1999) 1193-1195. [PMID: 9880484]
5. Mo, H., Dai, Y., Pochapsky, S.S. and Pochapsky, T.C. 1H, 13C and 15N NMR assignments for a carbon monoxide generating metalloenzyme from Klebsiella pneumoniae. J. Biomol. NMR 14 (1999) 287-288. [PMID: 10481280]
6. Dai, Y., Pochapsky, T.C. and Abeles, R.H. Mechanistic studies of two dioxygenases in the methionine salvage pathway of Klebsiella pneumoniae. Biochemistry 40 (2001) 6379-6387. [PMID: 11371200]
7. Al-Mjeni, F., Ju, T., Pochapsky, T.C. and Maroney, M.J. XAS investigation of the structure and function of Ni in acireductone dioxygenase. Biochemistry 41 (2002) 6761-6769. [PMID: 12022880]
8. Pochapsky, T.C., Pochapsky, S.S., Ju, T., Mo, H., Al-Mjeni, F. and Maroney, M.J. Modeling and experiment yields the structure of acireductone dioxygenase from Klebsiella pneumoniae. Nat. Struct. Biol. 9 (2002) 966-972. [PMID: 12402029]
Common name: acireductone dioxygenase [iron(II)-requiring]
Reaction: 1,2-dihydroxy-5-(methylthio)pent-1-en-3-one + O2 = 4-(methylthio)-2-oxobutanoate + formate
For diagram, click here
Other name(s): ARD'; 2-hydroxy-3-keto-5-thiomethylpent-1-ene dioxygenase (ambiguous); acireductone dioxygenase (ambiguous); E-2'
Systematic name: 1,2-dihydroxy-5-(methylthio)pent-1-en-3-one:oxygen oxidoreductase (formate-forming)
Comments: Requires iron(II). If Ni2+ is bound instead of iron(II), the reaction catalysed by EC 1.13.11.53, acireductone dioxygenase (Ni2+-requiring), occurs instead. The enzyme from Klebsiella oxytoca (formerly Klebsiella pneumoniae) ATCC strain 8724 is involved in the methionine salvage pathway.
Links to other databases: BRENDA, ERGO, EXPASY, KEGG, CAS registry number:
References:
1. Wray, J.W. and Abeles, R.H. A bacterial enzyme that catalyzes formation of carbon monoxide. J. Biol. Chem. 268 (1993) 21466-21469. [PMID: 8407993]
2. Wray, J.W. and Abeles, R.H. The methionine salvage pathway in Klebsiella pneumoniae and rat liver. Identification and characterization of two novel dioxygenases. J. Biol. Chem. 270 (1995) 3147-3153. [PMID: 7852397]
3. Furfine, E.S. and Abeles, R.H. Intermediates in the conversion of 5'-S-methylthioadenosine to methionine in Klebsiella pneumoniae. J. Biol. Chem. 263 (1988) 9598-9606. [PMID: 2838472]
4. Dai, Y., Wensink, P.C. and Abeles, R.H. One protein, two enzymes. J. Biol. Chem. 274 (1999) 1193-1195. [PMID: 9880484]
5. Mo, H., Dai, Y., Pochapsky, S.S. and Pochapsky, T.C. 1H, 13C and 15N NMR assignments for a carbon monoxide generating metalloenzyme from Klebsiella pneumoniae. J. Biomol. NMR 14 (1999) 287-288. [PMID: 10481280]
6. Dai, Y., Pochapsky, T.C. and Abeles, R.H. Mechanistic studies of two dioxygenases in the methionine salvage pathway of Klebsiella pneumoniae. Biochemistry 40 (2001) 6379-6387. [PMID: 11371200]
7. Al-Mjeni, F., Ju, T., Pochapsky, T.C. and Maroney, M.J. XAS investigation of the structure and function of Ni in acireductone dioxygenase. Biochemistry 41 (2002) 6761-6769. [PMID: 12022880]
8. Pochapsky, T.C., Pochapsky, S.S., Ju, T., Mo, H., Al-Mjeni, F. and Maroney, M.J. Modeling and experiment yields the structure of acireductone dioxygenase from Klebsiella pneumoniae. Nat. Struct. Biol. 9 (2002) 966-972. [PMID: 12402029]
Common name: sulfur oxygenase/reductase
Reaction: 4 sulfur + 4 H2O + O2 = 2 hydrogen sulfide + 2 bisulfite + 2 H+
Other name(s): SOR; sulfur oxygenase; sulfur oxygenase reductase
Systematic name: sulfur:oxygen oxidoreductase (hydrogen-sulfide- and sulfite-forming)
Comments: This enzyme, which is found in thermophilic microorganisms, contains one mononuclear none-heme iron centre per subunit. Elemental sulfur is both the electron donor and one of the two known acceptors, the other being oxygen. Another reaction product is thiosulfate, but this is probably formed non-enzymically at elevated temperature from sulfite and sulfur [1]. This enzyme differs from EC 1.13.11.18, sulfur dioxygenase and EC 1.97.1.3, sulfur reductase, in that both activities are found together.
Links to other databases: BRENDA, ERGO, EXPASY, KEGG, CAS registry number:
References:
1. Kletzin, A. Coupled enzymatic production of sulfite, thiosulfate, and hydrogen sulfide from sulfur: purification and properties of a sulfur oxygenase reductase from the facultatively anaerobic archaebacterium Desulfurolobus ambivalens. J. Bacteriol. 171 (1989) 1638-1643. [PMID: 2493451]
2. Kletzin, A. Molecular characterization of the sor gene, which encodes the sulfur oxygenase/reductase of the thermoacidophilic Archaeum Desulfurolobus ambivalens. J. Bacteriol. 174 (1992) 5854-5859. [PMID: 1522063]
3. Sun, C.W., Chen, Z.W., He, Z.G., Zhou, P.J. and Liu, S.J. Purification and properties of the sulfur oxygenase/reductase from the acidothermophilic archaeon, Acidianus strain S5. Extremophiles 7 (2003) 131-134. [PMID: 12664265]
4. Urich, T., Bandeiras, T.M., Leal, S.S., Rachel, R., Albrecht, T., Zimmermann, P., Scholz, C., Teixeira, M., Gomes, C.M. and Kletzin, A. The sulphur oxygenase reductase from Acidianus ambivalens is a multimeric protein containing a low-potential mononuclear non-haem iron centre. Biochem. J. 381 (2004) 137-146. [PMID: 15030315]
Common name: chlorophyllide a oxygenase
Reaction: (1) chlorophyllide a + O2 + NADPH + H+ = 7-hydroxychlorophyllide a + H2O + NADP+
(2) 7-hydroxychlorophyllide a + O2 + NADPH + H+ = chlorophyllide b + 2 H2O + NADP+
Other name(s): chlorophyllide a oxygenase; cholorophyll-b synthase; CAO
Systematic name: chlorophyllide a:oxygen 7-oxidoreductase
Comments: Chlorophyll b is required for the assembly of stable light-harvesting complexes (LHCs) in the chloroplast of green algae, cyanobacteria and plants [2,3]. Contains a mononuclear iron centre [3]. The enzyme catalyses two successive hydroxylations at the 7-methyl group of chlorophyllide a. The second step yields the aldehyde hydrate, which loses H2O spontaneously to form chlorophyllide b [2]. Chlorophyll a and protochlorophyllide a are not substrates [2].
Links to other databases: BRENDA, ERGO, EXPASY, KEGG, CAS registry number:
References:
1. Espineda, C.E., Linford, A.S., Devine, D. and Brusslan, J.A. The AtCAO gene, encoding chlorophyll a oxygenase, is required for chlorophyll b synthesis in Arabidopsis thaliana. Proc. Natl. Acad. Sci. USA 96 (1999) 10507-10511. [PMID: 10468639]
2. Oster, U., Tanaka, R., Tanaka, A. and Rudiger, W. Cloning and functional expression of the gene encoding the key enzyme for chlorophyll b biosynthesis (CAO) from Arabidopsis thaliana. Plant J. 21 (2000) 305-310. [PMID: 10758481]
3. Eggink, L.L., LoBrutto, R., Brune, D.C., Brusslan, J., Yamasato, A., Tanaka, A. and Hoober, J.K. Synthesis of chlorophyll b: localization of chlorophyllide a oxygenase and discovery of a stable radical in the catalytic subunit. BMC Plant Biol. 4 (2004) 5 only. [PMID: 15086960]
4. Porra, R.J., Schafer, W., Cmiel, E., Katheder, I. and Scheer, H. The derivation of the formyl-group oxygen of chlorophyll b in higher plants from molecular oxygen. Achievement of high enrichment of the 7-formyl-group oxygen from 18O2 in greening maize leaves. Eur. J. Biochem. 219 (1994) 671-679. [PMID: 8307032]
[EC 1.14.13.65 Deleted entry: 2-hydroxyquinoline 8-monooxygenase (EC 1.14.13.65 created 1999, deleted 2006)]
Common name: senecionine N-oxygenase
Reaction: senecionine + NADPH + H+ + O2 = senecionine N-oxide + NADP+ + H2O
Other name(s): senecionine monooxygenase (N-oxide-forming); SNO
Systematic name: senecionine,NADPH:oxygen oxidoreductase (N-oxide-forming)
Comments: A flavoprotein. NADH cannot replace NADPH. While pyrrolizidine alkaloids of the senecionine and monocrotaline types are generally good substrates (e.g. senecionine, retrorsine and monocrotaline), the enzyme does not use ester alkaloids lacking an hydroxy group at C-7 (e.g. supinine and phalaenopsine), 1,2-dihydro-alkaloids (e.g. sarracine) or unesterified necine bases (e.g. senkirkine) as substrates [1]. Senecionine N-oxide is used by insects as a chemical defense: senecionine N-oxide is non-toxic, but it is bioactivated to a toxic form by the action of cytochrome P-450 oxidase when absorbed by insectivores.
Links to other databases: BRENDA, ERGO, EXPASY, KEGG, CAS registry number: 220581-68-0
References:
1. Lindigkeit, R., Biller, A., Buch, M., Schiebel, H.M., Boppre, M. and Hartmann, T. The two facies of pyrrolizidine alkaloids: the role of the tertiary amine and its N-oxide in chemical defense of insects with acquired plant alkaloids. Eur. J. Biochem. 245 (1997) 626-636. [PMID: 9182998]
2. Naumann, C., Hartmann, T. and Ober, D. Evolutionary recruitment of a flavin-dependent monooxygenase for the detoxification of host plant-acquired pyrrolizidine alkaloids in the alkaloid-defended arctiid moth Tyria jacobaeae. Proc. Natl. Acad. Sci. USA 99 (2002) 6085-6090. [PMID: 11972041]
Common name: heme oxygenase
Reaction: heme + 3 AH2 + 3 O2 = biliverdin + Fe2+ + CO + 3 A + 3 H2O
For diagram, click here
Other name(s): ORP33 proteins; haem oxygenase; heme oxygenase (decyclizing); heme oxidase; haem oxidase
Systematic name: heme,hydrogen-donor:oxygen oxidoreductase (α-methene-oxidizing, hydroxylating)
Comments: Requires NAD(P)H and EC 1.6.2.4, NADPH—hemoprotein reductase. The terminal oxygen atoms that are incorporated into the carbonyl groups of pyrrole rings A and B of biliverdin are derived from two separate oxygen molecules [4]. The third oxygen molecule provides the oxygen atom that converts the α-carbon to CO. The central iron is kept in the reduced state by NAD(P)H.
Links to other databases: BRENDA, ERGO, EXPASY, KEGG, PDB, CAS registry number: 9059-22-7
References:
1. Maines, M.D., Ibrahim, N.G. and Kappas, K. Solubilization and partial purification of heme oxygenase from rat liver. J. Biol. Chem. 252 (1977) 5900-5903. [PMID: 18477]
2. Sunderman, F.W., Jr., Downs, J.R., Reid, M.C. and Bibeau, L.M. Gas-chromatographic assay for heme oxygenase activity. Clin. Chem. 28 (1982) 2026-2032. [PMID: 6897023]
3. Yoshida, T., Takahashi, S. and Kikuchi, J. Partial purification and reconstitution of the heme oxygenase system from pig spleen microsomes. J. Biochem. (Tokyo) 75 (1974) 1187-1191. [PMID: 4370250]
4. Noguchi, M., Yoshida, T. and Kikuchi, G. Specific requirement of NADPH-cytochrome c reductase for the microsomal heme oxygenase reaction yielding biliverdin IX α. FEBS Lett. 98 (1979) 281-284. [PMID: 105935]
5. Lad, L., Schuller, D.J., Shimizu, H., Friedman, J., Li, H., Ortiz de Montellano, P.R. and Poulos, T.L. Comparison of the heme-free and -bound crystal structures of human heme oxygenase-1. J. Biol. Chem. 278 (2003) 7834-7843. [PMID: 12500973]
Common name: uracil/thymine dehydrogenase
Reaction: (1) uracil + H2O + acceptor = barbiturate + reduced acceptor
(2) thymine + H2O + acceptor = 5-methylbarbiturate + reduced acceptor
For diagram, click here
Other name(s): uracil oxidase; uracil-thymine oxidase; uracil dehydrogenase
Systematic name: uracil:acceptor oxidoreductase
Comments: Forms part of the oxidative pyrimidine-degrading pathway in some microorganisms, along with EC 3.5.2.1 (barbiturase) and EC 3.5.1.95 (N-malonylurea hydrolase). Mammals, plants and other microorganisms utilize the reductive pathway, comprising EC 1.3.1.1 [dihydrouracil dehydrogenase (NAD+)] or EC 1.3.1.2 [dihydropyrimidine dehydrogenase (NADP+)], EC 3.5.2.2 (dihydropyrimidinase) and EC 3.5.1.6 (β-ureidopropionase), with the ultimate degradation products being an L-amino acid, NH3 and CO2 [5].
Links to other databases: BRENDA, ERGO, EXPASY, KEGG, CAS registry number:
References:
1. Hayaishi, O. and Kornberg, A. Metabolism of cytosine, thymine, uracil, and barbituric acid by bacterial enzymes. J. Biol. Chem. 197 (1952) 717-723. [PMID: 12981104]
2. Wang, T.P. and Lampen, J.O. Metabolism of pyrimidines by a soil bacterium. J. Biol. Chem. 194 (1952) 775-783. [PMID: 14927671]
3. Wang, T.P. and Lampen, J.O. Metabolism of pyrimidines by a soil bacterium. J. Biol. Chem. 194 (1952) 775-783. [PMID: 14927671]
4. Lara, F.J.S. On the decomposition of pyrimidines by bacteria. II. Studies with cell-free enzyme preparations. J. Bacteriol. 64 (1952) 279-285. [PMID: 14955523]
5. Soong, C.L., Ogawa, J. and Shimizu, S. Novel amidohydrolytic reactions in oxidative pyrimidine metabolism: analysis of the barbiturase reaction and discovery of a novel enzyme, ureidomalonase. Biochem. Biophys. Res. Commun. 286 (2001) 222-226. [PMID: 11485332]