Continued from EC 5.1.1.1 to EC 5.1.2.6
EC 5.1.3 Acting on Carbohydrates and Derivatives
EC 5.1.99 Acting on Other Compounds
Accepted name: ribulose-phosphate 3-epimerase
Reaction: D-ribulose 5-phosphate = D-xylulose 5-phosphate
For diagram of reaction click here, alternative click here.
Other name(s): phosphoribulose epimerase; erythrose-4-phosphate isomerase; phosphoketopentose 3-epimerase; xylulose phosphate 3-epimerase; phosphoketopentose epimerase; ribulose 5-phosphate 3-epimerase; D-ribulose phosphate-3-epimerase; D-ribulose 5-phosphate epimerase; D-ribulose-5-P 3-epimerase; D-xylulose-5-phosphate 3-epimerase; pentose-5-phosphate 3-epimerase
Systematic name: D-ribulose-5-phosphate 3-epimerase
Comments: The enzyme also converts D-erythrose 4-phosphate into D-erythrulose 4-phosphate and D-threose 4-phosphate.
Links to other databases: BRENDA, EXPASY, GTD, KEGG, Metacyc, PDB, CAS registry number: 9024-20-8
References:
1. Ashwell, G. and Hickman, J. Enzymatic formation of xylulose 5-phosphate from ribose 5-phosphate in spleen. J. Biol. Chem. 226 (1957) 65-76.
2. Dickens, F. and Williamson, D.H. Pentose phosphate isomerase and epimerase from animal tissues. Biochem. J. 64 (1956) 567-578.
3. Hurwitz, J. and Horecker, B.L. The purification of phosphoketopentoepimerase from Lactobacillus pentosus and the preparation of xylulose 5-phosphate. J. Biol. Chem. 223 (1956) 993-1008.
4. Stumpf, P.K. and Horecker, B.L. The rôle of xylulose 5-phosphate in xylose metabolism of Lactobacillus pentosus. J. Biol. Chem. 218 (1956) 753-768.
5. Terada, H., Mukae, K., Hosomi, S., Mizoguchi, T. and Uehara, K. Characterization of an enzyme which catalyzes isomerization and epimerization of D-erythrose 4-phosphate. Eur. J. Biochem. 148 (1985) 345-351. [PMID: 3987693]
Accepted name: UDP-glucose 4-epimerase
Reaction: UDP-glucose = UDP-galactose
For diagram of reaction click here.
Other name(s): UDP-galactose 4-epimerase; uridine diphosphoglucose epimerase; galactowaldenase; UDPG-4-epimerase; uridine diphosphate galactose 4-epimerase; uridine diphospho-galactose-4-epimerase; UDP-glucose epimerase; UDP-galactose 4-epimerase; 4-epimerase; UDPG-4-epimerase; uridine diphosphoglucose 4-epimerase; uridine diphosphate glucose 4-epimerase; UDP-D-galactose 4-epimerase
Systematic name: UDP-glucose 4-epimerase
Comments: Requires NAD+. Also acts on UDP-2-deoxyglucose.
Links to other databases: BRENDA, EXPASY, GTD, KEGG, Metacyc, PDB, CAS registry number: 9032-89-7
References:
1. Leloir, L.F. Enzymic isomerization and related processes. Adv. Enzymol. Relat. Subj. Biochem. 14 (1953) 193-218.
2. Maxwell, E.S. and de Robichon-Szulmajster, H. Purification of uridine diphosphate galactose-4-epimerase from yeast and the identification of protein-bound diphosphopyridine nucleotide. J. Biol. Chem. 235 (1960) 308-312.
3. Wilson, D.B. and Hogness, D.S. The enzymes of the galactose operon in Escherichia coli. I. Purification and characterization of uridine diphosphogalactose 4-epimerase. J. Biol. Chem. 239 (1964) 2469-2481.
Accepted name: aldose 1-epimerase
Reaction: α-D-glucose = β-D-glucose
Other name(s): mutarotase; aldose mutarotase; galactose mutarotase; galactose 1-epimerase; D-galactose 1-epimerase
Systematic name: aldose 1-epimerase
Comments: Also acts on L-arabinose, D-xylose, D-galactose, maltose and lactose. This enzyme catalyses the first step in galactose metabolism by converting β-D-galactose into α-D-galactose, which is the substrate for EC 2.7.1.6, galactokinase [5,6].
Links to other databases: BRENDA, EXPASY, KEGG, Metacyc, PDB, CAS registry number: 9031-76-9
References:
1. Bentley, R. and Bhate, D.S. Mutarotase from Penicillium notatum. I. Purification, assay, and general properties of the enzyme. J. Biol. Chem. 235 (1960) 1219-1224. [PMID: 13799037]
2. Bentley, R. and Bhate, D.S. Mutarotase from Penicillium notatum. II. The mechanism of the mutarotation reaction. J. Biol. Chem. 235 (1960) 1225-1233. [PMID: 13799038]
3. Keilin, D. and Hartree, E.F. Biological catalysis of mutarotation of glucose. Biochem. J. 50 (1952) 341-348. [PMID: 14915955]
4. Levy, G.B. and Cook, E.S. A rotographic study of mutarotase. Biochem. J. 57 (1954) 50-55. [PMID: 13159947]
5. Beebe, J.A. and Frey, P.A. Galactose mutarotase: purification, characterization, and investigations of two important histidine residues. Biochemistry 37 (1998) 14989-14997. [PMID: 9778377]
6. Thoden, J.B., Timson, D.J., Reece, R.J. and Holden, H.M. Molecular structure of human galactose mutarotase. J. Biol. Chem. 279 (2004) 23431-23437. [PMID: 15026423]
7. Thoden, J.B., Kim, J., Raushel, F.M. and Holden, H.M. The catalytic mechanism of galactose mutarotase. Protein Sci. 12 (2003) 1051-1059. [PMID: 12717027]
Accepted name: L-ribulose-5-phosphate 4-epimerase
Reaction: L-ribulose 5-phosphate = D-xylulose 5-phosphate
For diagram click here or click here.
Other name(s): phosphoribulose isomerase; ribulose phosphate 4-epimerase; L-ribulose-phosphate 4-epimerase; L-ribulose 5-phosphate 4-epimerase; AraD; L-Ru5P
Systematic name: L-ribulose-5-phosphate 4-epimerase
Comments: Requires a divalent cation for activity.
Links to other databases: BRENDA, EXPASY, GTD, KEGG, Metacyc, PDB, CAS registry number: 9024-19-5
References:
1. Burma, D.P. and Horecker, B.L. IV.
2. Deupree, J.D. and Wood, W.A. L-Ribulose 5-phosphate 4-epimerase of Aerobacter aerogenes. Evidence for nicotinamide adenine dinucleotide-independent 4-epimerization by the crystalline enzyme. J. Biol. Chem. 245 (1970) 3988-3995. [PMID: 4395381]
3. Lee, N., Patrick, J.W. and Masson, M. Crystalline L-ribulose 5-phosphate 4-epimerase from Escherichia coli. J. Biol. Chem. 243 (1968) 4700-4705. [PMID: 4879898]
4. Wolin, M.J., Simpson, F.J. and Wood, W.A. Degradation of L-arabinose by Aerobacter aerogenes. III. Identification and properties of L-ribulose-5-phosphate 4-epimerase. J. Biol. Chem. 232 (1958) 559-575. [PMID: 13549442]
5. Andersson, A., Schneider, G. and Lindqvist, Y. Purification and preliminary X-ray crystallographic studies of recombinant L-ribulose-5-phosphate 4-epimerase from Escherichia coli. Protein Sci. 4 (1995) 1648-1650. [PMID: 8520491]
6. Lee, L.V., Poyner, R.R., Vu, M.V. and Cleland, W.W. Role of metal ions in the reaction catalyzed by L-ribulose-5-phosphate 4-epimerase. Biochemistry 39 (2000) 4821-4830. [PMID: 10769139]
7. Samuel, J., Luo, Y., Morgan, P.M., Strynadka, N.C. and Tanner, M.E. Catalysis and binding in L-ribulose-5-phosphate 4-epimerase: a comparison with L-fuculose-1-phosphate aldolase. Biochemistry 40 (2001) 14772-14780. [PMID: 11732896]
Accepted name: UDP-arabinose 4-epimerase
Reaction: UDP-L-arabinose = UDP-D-xylose
For diagram of reaction click here.
Other name(s): uridine diphosphoarabinose epimerase; UDP arabinose epimerase; uridine 5'-diphosphate-D-xylose 4-epimerase; UDP-D-xylose 4-epimerase
Systematic name: UDP-L-arabinose 4-epimerase
Links to other databases: BRENDA, EXPASY, GTD, KEGG, Metacyc, CAS registry number: 9024-18-4
References:
1. Feingold, D.S., Neufeld, E.F. and Hassid, W.Z. The 4-epimerization and decarboxylation of uridine diphosphate D-glucuronic acid by extracts from Phaseolus aureus seedlings. J. Biol. Chem. 235 (1960) 910-913.
Accepted name: UDP-glucuronate 4-epimerase
Reaction: UDP-glucuronate = UDP-D-galacturonate
For diagram of reaction click here.
Other name(s): uridine diphospho-D-galacturonic acid; UDP glucuronic epimerase; uridine diphosphoglucuronic epimerase; UDP-galacturonate 4-epimerase; uridine diphosphoglucuronate epimerase; UDP-D-galacturonic acid 4-epimerase
Systematic name: UDP-glucuronate 4-epimerase
Links to other databases: BRENDA, EXPASY, GTD, KEGG, Metacyc, CAS registry number: 9024-17-3
References:
1. Feingold, D.S., Neufeld, E.F. and Hassid, W.Z. The 4-epimerization and decarboxylation of uridine diphosphate D-glucuronic acid by extracts from Phaseolus aureus seedlings. J. Biol. Chem. 235 (1960) 910-913.
Accepted name: UDP-N-acetylglucosamine 4-epimerase
Reaction: UDP-N-acetyl-α-D-glucosamine = UDP-N-acetyl-α-D-galactosamine
For diagram of reaction click here.
Other name(s): UDP acetylglucosamine epimerase; uridine diphosphoacetylglucosamine epimerase; uridine diphosphate N-acetylglucosamine-4-epimerase; uridine 5'-diphospho-N-acetylglucosamine-4-epimerase; UDP-N-acetyl-D-glucosamine 4-epimerase
Systematic name: UDP-N-acetyl-α-D-glucosamine 4-epimerase
Links to other databases: BRENDA, EXPASY, KEGG, Metacyc, PDB, CAS registry number: 9024-16-2
References:
1. Glaser, L. The biosynthesis of N-acetylgalactosamine. J. Biol. Chem. 234 (1959) 2801-2805.
2. Kornfeld, S. and Glaser, L. The synthesis of thymidine-linked sugars. V. Thymidine diphosphate-amino sugars. J. Biol. Chem. 237 (1962) 3052-3059.
Accepted name: N-acylglucosamine 2-epimerase
Reaction: N-acyl-D-glucosamine = N-acyl-D-mannosamine
Other name(s): acylglucosamine 2-epimerase; N-acetylglucosamine 2-epimerase
Systematic name: N-acyl-D-glucosamine 2-epimerase
Comments: Requires catalytic amounts of ATP.
Links to other databases: BRENDA, EXPASY, GTD, KEGG, Metacyc, PDB, CAS registry number: 37318-34-6
References:
1. Ghosh, S. and Roseman, S. The sialic acids. V. N-Acyl-D-glucosamine 2-epimerase. J. Biol. Chem. 240 (1965) 1531-1536.
Accepted name: N-acylglucosamine-6-phosphate 2-epimerase
Reaction: N-acyl-D-glucosamine 6-phosphate = N-acyl-D-mannosamine 6-phosphate
Other name(s): acylglucosamine-6-phosphate 2-epimerase; acylglucosamine phosphate 2-epimerase
Systematic name: N-acyl-D-glucosamine-6-phosphate 2-epimerase
Links to other databases: BRENDA, EXPASY, GTD, KEGG, Metacyc, PDB, CAS registry number: 37318-35-7
References:
1. Ghosh, S. and Roseman, S. The sialic acids. IV. N-Acyl-D-glucosamine 6-phosphate 2-epimerase. J. Biol. Chem. 240 (1965) 1525-1530. [PMID: 14285487]
Accepted name: CDP-paratose 2-epimerase
Reaction: CDP-α-D-paratose = CDP-α-D-tyvelose
For diagram click here.
Glossary: CDP-α-D-tyvelose = CDP-3,6-dideoxy-α-D-mannose = CDP-3,6-dideoxy-α-D-arabino-hexose
CDP-α-D-paratose = CDP-3,6-dideoxy-α-D-glucose = CDP-3,6-dideoxy-α-D-ribo-hexose
Other name(s): CDP-paratose epimerase; cytidine diphosphoabequose epimerase; cytidine diphosphodideoxyglucose epimerase; cytidine diphosphoparatose epimerase; cytidine diphosphate paratose-2-epimerase; CDP-abequose epimerase (incorrect); CDP-D-abequose 2-epimerase (incorrect)
Systematic name: CDP-3,6-dideoxy-D-glucose 2-epimerase
Comments: Requires NAD+. CDP-paratose (CDP-3,6-dideoxy-D-glucose), is more systematically called CDP-α-3,6-dideoxy-D-ribo-hexose. CDP-tyvelose (CDP-3,6-dideoxy-D-mannose) is systematically called CDP-3,6-dideoxy-D-arabino-hexose.
Links to other databases: BRENDA, EXPASY, GTD, KEGG, Metacyc, PDB, CAS registry number: 37318-36-8
References:
1. Matsuhashi, S. Enzymatic synthesis of cytidine diphosphate 3,6-dideoxyhexoses. II. Reversible 2-epimerization of cytidine diphosphate paratose. J. Biol. Chem. 241 (1966) 4275-4282. [PMID: 5924649]
2. Liu, H.-W. and Thorson, J.S. Pathways and mechanisms in the biogenesis of novel deoxysugars by bacteria. Annu. Rev. Microbiol. 48 (1994) 223-256. [PMID: 7826006]
Accepted name: cellobiose epimerase
Reaction: cellobiose = 4-O-β-D-glucopyranosyl-D-mannose
Glossary: cellobiose = 4-O-β-D-glucopyranosyl-D-glucose
Systematic name: cellobiose 2-epimerase
Comments: The enzyme catalyses the interconversion between D-glucose and D-mannose residues at the reducing end of β-1,4-linked disaccharides by epimerizing the hydroxyl group at the C-2 position of the glucose moiety.
Links to other databases: BRENDA, EXPASY, KEGG, Metacyc, PDB, CAS registry number: 37318-37-9
References:
1. Tyler, T.R. and Leatherwood, J.M. Epimerization of disaccharides by enzyme preparations from Ruminococcus albus. Arch. Biochem. Biophys. 119 (1967) 363-367. [PMID: 6069974]
2. Ito, S., Taguchi, H., Hamada, S., Kawauchi, S., Ito, H., Senoura, T., Watanabe, J., Nishimukai, M., Ito, S. and Matsui, H. Enzymatic properties of cellobiose 2-epimerase from Ruminococcus albus and the synthesis of rare oligosaccharides by the enzyme. Appl. Microbiol. Biotechnol. 79 (2008) 433-441. [PMID: 18392616]
3. Fujiwara, T., Saburi, W., Inoue, S., Mori, H., Matsui, H., Tanaka, I. and Yao, M. Crystal structure of Ruminococcus albus cellobiose 2-epimerase: structural insights into epimerization of unmodified sugar. FEBS Lett 587 (2013) 840-846. [PMID: 23462136]
[EC 5.1.3.12 Deleted entry: UDP-glucuronate 5-epimerase. The enzyme has never been purified and the activity was later shown not to exist. (EC 5.1.3.12 created 1972, deleted 2020)]
Accepted name: dTDP-4-dehydrorhamnose 3,5-epimerase
Reaction: dTDP-4-dehydro-6-deoxy-α-D-glucose = dTDP-4-dehydro-β-L-rhamnose
For diagram click here.
Glossary: dTDP-4-dehydro-β-L-rhamnose = dTDP-4-dehydro-6-deoxy-β-L-mannose
Other name(s): dTDP-L-rhamnose synthetase; dTDP-L-rhamnose synthetase; thymidine diphospho-4-ketorhamnose 3,5-epimerase; TDP-4-ketorhamnose 3,5-epimerase; dTDP-4-dehydro-6-deoxy-D-glucose 3,5-epimerase; TDP-4-keto-L-rhamnose-3,5-epimerase; dTDP-4-dehydro-6-deoxy-D-glucose 3,5-epimerase
Systematic name: dTDP-4-dehydro-6-deoxy-α-D-glucose 3,5-epimerase
Comments: The enzyme occurs in a complex with EC 1.1.1.133 dTDP-4-dehydrorhamnose reductase.
Links to other databases: BRENDA, EXPASY, KEGG, Metacyc, PDB, CAS registry number: 37318-39-1
References:
1. Gaugler, R.W. and Gabriel, O. Biological mechanisms involved in the formation of deoxy sugars. VII. Biosynthesis of 6-deoxy-L-talose. J. Biol. Chem. 248 (1973) 6041-6049. [PMID: 4199258]
2. Melo, A. and Glaser, L. The mechanism of 6-deoxyhexose synthesis. II. Conversion of deoxythymidine diphosphate 4-keto-6-deoxy-D-glucose to deoxythymidine diphosphate L-rhamnose. J. Biol. Chem. 243 (1968) 1475-1478. [PMID: 4384782]
Accepted name: UDP-N-acetylglucosamine 2-epimerase (non-hydrolysing)
Reaction: UDP-N-acetyl-α-D-glucosamine = UDP-N-acetyl-α-D-mannosamine
For diagram of reaction click here
Other name(s): UDP-N-acetylglucosamine 2'-epimerase (ambiguous); uridine diphosphoacetylglucosamine 2'-epimerase (ambiguous); uridine diphospho-N-acetylglucosamine 2'-epimerase (ambiguous); uridine diphosphate-N-acetylglucosamine-2'-epimerase (ambiguous); rffE (gene name); mnaA (gene name); UDP-N-acetyl-D-glucosamine 2-epimerase
Systematic name: UDP-N-acetyl-α-D-glucosamine 2-epimerase
Comments: This bacterial enzyme catalyses the reversible interconversion of UDP-GlcNAc and UDP-ManNAc. The latter is used in a variety of bacterial polysaccharide biosyntheses. cf. EC 3.2.1.183, UDP-N-acetylglucosamine 2-epimerase (hydrolysing).
Links to other databases: BRENDA, EXPASY, KEGG, Metacyc, PDB, CAS registry number: 9037-71-2
References:
1. Kawamura, T., Kimura, M., Yamamori, S. and Ito, E. Enzymatic formation of uridine diphosphate N-acetyl-D-mannosamine. J. Biol. Chem. 253 (1978) 3595-3601. [PMID: 418068]
2. Meier-Dieter, U., Starman, R., Barr, K., Mayer, H. and Rick, P.D. Biosynthesis of enterobacterial common antigen in Escherichia coli. Biochemical characterization of Tn10 insertion mutants defective in enterobacterial common antigen synthesis. J. Biol. Chem. 265 (1990) 13490-13497. [PMID: 2166030]
3. Morgan, P. M., Sala, R. F., and Tanner, M. E. Eliminations in the reactions catalyzed by UDP-N-acetylglucosamine 2-epimerase. J. Am. Chem. Soc. 119 (1997) 10269-10277.
4. Campbell, R.E., Mosimann, S.C., Tanner, M.E. and Strynadka, N.C. The structure of UDP-N-acetylglucosamine 2-epimerase reveals homology to phosphoglycosyl transferases. Biochemistry 39 (2000) 14993-15001. [PMID: 11106477]
5. Samuel, J. and Tanner, M.E. Active site mutants of the "non-hydrolyzing" UDP-N-acetylglucosamine 2-epimerase from Escherichia coli. Biochim. Biophys. Acta 1700 (2004) 85-91. [PMID: 15210128]
6. Soldo, B., Lazarevic, V., Pooley, H.M. and Karamata, D. Characterization of a Bacillus subtilis thermosensitive teichoic acid-deficient mutant: gene mnaA (yvyH) encodes the UDP-N-acetylglucosamine 2-epimerase. J. Bacteriol. 184 (2002) 4316-4320. [PMID: 12107153]
Accepted name: glucose-6-phosphate 1-epimerase
Reaction: α-D-glucose 6-phosphate = β-D-glucose 6-phosphate
Systematic name: D-glucose-6-phosphate 1-epimerase
Links to other databases: BRENDA, EXPASY, GTD, KEGG, Metacyc, PDB, CAS registry number: 37259-65-7
References:
1. Wurster, B. and Hess, B. Glucose-6-phosphate-1-epimerase from baker's yeast. A new enzyme. FEBS Lett. 23 (1972) 341-348.
Accepted name: UDP-glucosamine 4-epimerase
Reaction: UDP-α-D-glucosamine = UDP-α-D-galactosamine
Systematic name: UDP-α-D-glucosamine 4-epimerase
Links to other databases: BRENDA, EXPASY, KEGG, Metacyc, PDB, CAS registry number:
References:
1. Maley, F. and Maley, G.F. The enzymic conversion of glucosamine to galactosamine. Biochim. Biophys. Acta 31 (1959) 577-578.
2. Silbert, J.E. and Brown, D.H. Enzymic synthesis of uridine diphosphate glucosamine and heparin from [14C]glucosamine by a mouse mast-cell tumor. Biochim. Biophys. Acta 54 (1961) 590-592.
Accepted name: heparosan-N-sulfate-glucuronate 5-epimerase
Reaction: Epimerization of D-glucuronate in heparosan-N-sulfate to L-iduronate.
Other name(s): heparosan epimerase; heparosan-N-sulfate-D-glucuronosyl 5-epimerase; C-5 uronosyl epimerase; polyglucuronate epimerase; D-glucuronyl C-5 epimerase; poly[(1,4)-β-D-glucuronosyl-(1,4)-N-sulfo-α-D-glucosaminyl] glucurono-5-epimerase
Systematic name: poly[(1→4)-β-D-glucuronosyl-(1→4)-N-sulfo-α-D-glucosaminyl] glucurono-5-epimerase
Comments: The enzyme acts on D-glucosyluronate residues in N-sulfated heparosan polymers, converting them to L-iduronate, thus modifying the polymer to heparan-N-sulfate. The enzyme requires that at least the N-acetylglucosamine residue linked to C-4 of the substrate has been deacetylated and N-sulfated, and activity is highest with fully N-sulfated substrate. It does not act on glucuronate residues that are O-sulfated or are adjacent to N-acetylglucosamine residues that are O-sulfated at the 6 position. Thus the epimerization from D-glucuronate to L-iduronate occurs after N-sulfation of glucosamine residues but before O-sulfation. Not identical with EC 5.1.3.19 chondroitin-glucuronate 5-epimerase or with EC 5.1.3.36, heparosan-glucuronate 5-epimerase.
Links to other databases: BRENDA, EXPASY, KEGG, MetaCyc, PDB, CAS registry number: 112567-86-9
References:
1. Jacobsson, I., Bäckström, G., Höök, M., Lindahl, U., Feingold, D.S., Malmström, A. and Rodén, L. Biosynthesis of heparin. Assay and properties of the microsomal uronosyl C-5 epimerase. J. Biol. Chem. 254 (1979) 2975-2982. [PMID: 107165]
2. Jacobsson, I., Lindahl, U., Jensen, J.W., Roden, L., Prihar, H. and Feingold, D.S. Biosynthesis of heparin. Substrate specificity of heparosan N-sulfate D-glucuronosyl 5-epimerase. J. Biol. Chem. 259 (1984) 1056-1063. [PMID: 6420398]
3. Hagner-McWhirter, A., Hannesson, H.H., Campbell, P., Westley, J., Roden, L., Lindahl, U. and Li, J.P. Biosynthesis of heparin/heparan sulfate: kinetic studies of the glucuronyl C5-epimerase with N-sulfated derivatives of the Escherichia coli K5 capsular polysaccharide as substrates. Glycobiology 10 (2000) 159-171. [PMID: 10642607]
Accepted name: GDP-mannose 3,5-epimerase
Reaction: (1) GDP-α-D-mannose = GDP-β-L-galactose
(2) GDP-α-D-mannose = GDP-β-L-gulose
Other name(s): GME (gene name); GDP-D-mannose:GDP-L-galactose epimerase; guanosine 5'-diphosphate D-mannose:guanosine 5'-diphosphate L-galactose epimerase
Systematic name: GDP-α-D-mannose 3,5-epimerase
Comments: The enzyme catalyses the formation of the stable intermediate GDP-β-L-gulose as well as GDP-β-L-galactose. The reaction proceeds by C4' oxidation of GDP-α-D-mannose followed by epimerization of the C5' position to give GDP-β-L-4-dehydro-gulose. This intermediate is either reduced to give GDP-β-L-gulose or the C3' position is epimerized to give GDP-β-L-4-dehydro-galactose, followed by C4' reduction to yield GDP-β-L-galactose. Both products serve as intermediates in two different variants of plant L-ascorbate biosynthesis pathways.
Links to other databases: BRENDA, EXPASY, GTD, KEGG, MetaCyc, PDB, CAS registry number: 72162-82-4
References:
1. Hebda, P.A., Behrman, E.J. and Barber, G.A. The guanosine 5'-diphosphate D-mannose: guanosine 5'-diphosphate L-galactose epimerase of Chlorella pyrenoidosa. Chemical synthesis of guanosine 5'-diphosphate L-galactose and further studies of the enzyme and the reaction it catalyzes. Arch. Biochem. Biophys. 194 (1979) 496-502. [PMID: 443816]
2. Barber, G.A. and Hebda, P.A. GDP-D-mannose: GDP-L-galactose epimerase from Chlorella pyrenoidosa. Methods Enzymol. 83 (1982) 522-525. [PMID: 7098948]
3. Wolucka, B.A., Persiau, G., Van Doorsselaere, J., Davey, M.W., Demol, H., Vandekerckhove, J., Van Montagu, M., Zabeau, M. and Boerjan, W. Partial purification and identification of GDP-mannose 3",5"-epimerase of Arabidopsis thaliana, a key enzyme of the plant vitamin C pathway. Proc. Natl. Acad. Sci. USA 98 (2001) 14843-14848. [PMID: 11752432]
4. Major, L.L., Wolucka, B.A. and Naismith, J.H. Structure and function of GDP-mannose-3',5'-epimerase: an enzyme which performs three chemical reactions at the same active site. J. Am. Chem. Soc. 127 (2005) 18309-18320. [PMID: 16366586]
5. Watanabe, K., Suzuki, K. and Kitamura, S. Characterization of a GDP-D-mannose 3'',5''-epimerase from rice. Phytochemistry 67 (2006) 338-346. [PMID: 16413588]
Accepted name: chondroitin-glucuronate 5-epimerase
Reaction: chondroitin D-glucuronate = dermatan L-iduronate
For diagram click here.
Other name(s): polyglucuronate 5-epimerase; dermatan-sulfate 5-epimerase; urunosyl C-5 epimerase; chondroitin D-glucuronosyl 5-epimerase
Systematic name: chondroitin-D-glucuronate 5-epimerase
Comments: Not identical with EC 5.1.3.17 heparosan-N-sulfate-glucuronate 5-epimerase.
Links to other databases: BRENDA, EXPASY, KEGG, Metacyc, PDB, CAS registry number: 70766-66-4
References:
1. Malmström, A. and Åberg, L. Biosynthesis of dermatan sulphate. Assay and properties of the uronosyl C-5 epimerase. Biochem. J. 201 (1982) 489-493. [PMID: 7092807]
Accepted name: ADP-glyceromanno-heptose 6-epimerase
Reaction: ADP-D-glycero-D-manno-heptose = ADP-L-glycero-D-manno-heptose
Systematic name: ADP-L-glycero-D-manno-heptose 6-epimerase
Comments: requires NAD+.
Links to other databases: BRENDA, EXPASY, KEGG, Metacyc, PDB, CAS registry number: 85030-75-7
References:
1. Ding, L., Seto, B.L., Ahmed, S.A., Coleman, W.G., Jr. Purification and properties of the Escherichia coli K-12 NAD-dependent nucleotide diphosphosugar epimerase, ADP-L-glycero-D-manno-heptose 6-epimerase. J. Biol. Chem. 269 (1994) 24384-24390. [PMID: 7929099]
2. Raetz, C.R.H. Biochemistry of endotoxins. Annu. Rev. Biochem. 58 (1990) 129-170. [PMID: 1695830]
Accepted name: maltose epimerase
Reaction: α-maltose = β-maltose
Systematic name: maltose 1-epimerase
Comments: The enzyme catalyses the interconversion of α and β anomers of maltose more effectively than those of disaccharides such as lactose and cellobiose.
Links to other databases: BRENDA, EXPASY, KEGG, Metacyc, CAS registry number: 166799-98-0
References:
1. Shirokane, Y. and Suzuki, M. A novel enzyme, maltose 1-epimerase from Lactobacillus brevis IFO 3345. FEBS Lett. 367 (1995) 177-179. [PMID: 7796915]
Accepted name: L-ribulose-5-phosphate 3-epimerase
Reaction: L-ribulose 5-phosphate = L-xylulose 5-phosphate
For diagram click here.
Other name(s): L-xylulose 5-phosphate 3-epimerase; UlaE; SgaU
Systematic name: L-ribulose-5-phosphate 3-epimerase
Comments: Along with EC 4.1.1.85, 3-dehydro-L-gulonate-6-phosphate decarboxylase, this enzyme is involved in a pathway for the utilization of L-ascorbate by Escherichia coli.
Links to other databases: BRENDA, EXPASY, KEGG, Metacyc, PDB, CAS registry number: 1114425-98-7
References:
1. Yew, W.S. and Gerlt, J.A. Utilization of L-ascorbate by Escherichia coli K-12: assignments of functions to products of the yif-sga and yia-sgb operons. J. Bacteriol. 184 (2002) 302-306. [PMID: 11741871]
Accepted name: UDP-2,3-diacetamido-2,3-dideoxyglucuronic acid 2-epimerase
Reaction: UDP-2,3-diacetamido-2,3-dideoxy-α-D-glucuronate = UDP-2,3-diacetamido-2,3-dideoxy-α-D-mannuronate
For diagram of reaction, click here
Glossary: UDP-α-D-GlcNAc3NAcA = UDP-2,3-diacetamido-2,3-dideoxy-α-D-glucuronic acid
UDP-α-D-ManNAc3NAcA = UDP-2,3-diacetamido-2,3-dideoxy-α-D-mannuronic acid
Other name(s): UDP-GlcNAc3NAcA 2-epimerase; UDP-α-D-GlcNAc3NAcA 2-epimerase; 2,3-diacetamido-2,3-dideoxy-α-D-glucuronic acid 2-epimerase; WbpI; WlbD
Systematic name: 2,3-diacetamido-2,3-dideoxy-α-D-glucuronate 2-epimerase
Comments: This enzyme participates in the biosynthetic pathway for UDP-α-D-ManNAc3NAcA (UDP-2,3-diacetamido-2,3-dideoxy-α-D-mannuronic acid), an important precursor of the B-band lipopolysaccharide of Pseudomonas aeroginosa serotype O5 and of the band-A trisaccharide of Bordetella pertussis, both important respiratory pathogens [1]. The enzyme is highly specific as UDP-α-D-GlcNAc, UDP-α-D-GlcNAcA (UDP-2-acetamido-2-deoxy-α-D-glucuronic acid) and UDP-α-D-GlcNAc3NAc (UDP-2,3-diacetamido-2,3-dideoxy-α-D-glucose) cannot act as substrates [1].
Links to other databases: BRENDA, EXPASY, KEGG, Metacyc, CAS registry number:
References:
1. Westman, E.L., McNally, D.J., Rejzek, M., Miller, W.L., Kannathasan, V.S., Preston, A., Maskell, D.J., Field, R.A., Brisson, J.R. and Lam, J.S. Identification and biochemical characterization of two novel UDP-2,3-diacetamido-2,3-dideoxy-α-D-glucuronic acid 2-epimerases from respiratory pathogens. Biochem. J. 405 (2007) 123-130. [PMID: 17346239]
2. Westman, E.L., McNally, D.J., Rejzek, M., Miller, W.L., Kannathasan, V.S., Preston, A., Maskell, D.J., Field, R.A., Brisson, J.R. and Lam, J.S. Erratum report: Identification and biochemical characterization of two novel UDP-2,3-diacetamido-2,3-dideoxy-α-D-glucuronic acid 2-epimerases from respiratory pathogens. Biochem. J. 405 (2007) 625 only.
3. Sri Kannathasan, V., Staines, A.G., Dong, C.J., Field, R.A., Preston, A.G., Maskell, D.J. and Naismith, J.H. Overexpression, purification, crystallization and data collection on the Bordetella pertussis wlbD gene product, a putative UDP-GlcNAc 2′-epimerase. Acta Crystallogr. D Biol. Crystallogr. 57 (2001) 1310-1312. [PMID: 11526328]
Accepted name: N-acetylneuraminate epimerase
Reaction: N-acetyl-α-neuraminate = N-acetyl-β-neuraminate (oveall reaction)
(1a) N-acetyl-α-neuraminate = aceneuramate
(1b) aceneuramate = N-acetyl-β-neuraminate
Glossary: aceneuramate = (4S,5R,6R,7S,8R)-5-acetamido-4,6,7,8,9-pentahydroxy-2-oxononanoate
Other name(s): sialic acid epimerase; N-acetylneuraminate mutarotase; NanM; NanQ
Systematic name: N-acetyl-α-neuraminate 2-epimerase
Comments: Sialoglycoconjugates present in vertebrates are linked exclusively by α-linkages and are released in α form during degradation. This enzyme accelerates maturotation to the β form via the open form (which also occurs as a slow spontaneous reaction). The open form is necessary for further metabolism by the bacteria.
Links to other databases: BRENDA, EXPASY, KEGG, MetaCyc, PDB, CAS registry number:
References:
1. Severi, E., Müller, A., Potts, J.R., Leech, A., Williamson, D., Wilson, K.S. and Thomas, G.H. Sialic acid mutarotation is catalyzed by the Escherichia coli β-propeller protein YjhT. J. Biol. Chem. 283 (2008) 4841-4849. [PMID: 18063573]
2. Kentache, T., Thabault, L., Deumer, G., Haufroid, V., Frederick, R., Linster, C.L., Peracchi, A., Veiga-da-Cunha, M., Bommer, G.T. and Van Schaftingen, E. The metalloprotein YhcH is an anomerase providing N-acetylneuraminate aldolase with the open form of its substrate. J. Biol. Chem. (2021) 100699. [PMID: 33895133]
Accepted name: dTDP-L-rhamnose 4-epimerase
Reaction: dTDP-6-deoxy-β-L-talose = dTDP-β-L-rhamnose
Glossary: dTDP-β-L-rhamnose = dTDP-6-deoxy-β-L-mannose
dTDP-6-deoxy-β-L-talose = dTDP-β-L-pneumose
Other name(s): dTDP-4-L-rhamnose 4-epimerase; wbiB (gene name)
Systematic name: dTDP-6-deoxy-β-L-talose 4-epimerase
Comments: The equilibrium is strongly towards dTDP-β-L-rhamnose.
Links to other databases: BRENDA, EXPASY, KEGG, Metacyc, CAS registry number:
References:
1. Yoo, H.G., Kwon, S.Y., Karki, S. and Kwon, H.J. A new route to dTDP-6-deoxy-L-talose and dTDP-L-rhamnose: dTDP-L-rhamnose 4-epimerase in Burkholderia thailandensis. Bioorg. Med. Chem. Lett. 21 (2011) 3914-3917. [PMID: 21640586]
Accepted name: N-acetyl-α-D-glucosaminyl-diphospho-ditrans,octacis-undecaprenol 4-epimerase
Reaction: N-acetyl-α-D-glucosaminyl-diphospho-ditrans,octacis-undecaprenol = N-acetyl-α-D-galactosaminyl-diphospho-ditrans,octacis-undecaprenol
Other name(s): GlcNAc-P-P-Und epimerase; GlcNAc-P-P-Und 4-epimerase; gne (gene name)
Systematic name: N-acetyl-α-D-glucosaminyl-diphospho-ditrans,octacis-undecaprenol 4-epimerase
Comments: The enzyme is involved in biosynthesis of the repeating tetrasaccharide unit of the O-antigen produced by some Gram-negative bacteria.
Links to other databases: BRENDA, EXPASY, KEGG, Metacyc, CAS registry number:
References:
1. Rush, J.S., Alaimo, C., Robbiani, R., Wacker, M. and Waechter, C.J. A novel epimerase that converts GlcNAc-P-P-undecaprenol to GalNAc-P-P-undecaprenol in Escherichia coli O157. J. Biol. Chem. 285 (2010) 1671-1680. [PMID: 19923219]
Accepted name: dTDP-4-dehydro-6-deoxy-D-glucose 3-epimerase
Reaction: dTDP-4-dehydro-6-deoxy-α-D-glucose = dTDP-4-dehydro-6-deoxy-α-D-gulose
For diagram of reaction, click here
Glossary: dTDP-4-dehydro-6-deoxy-α-D-gulose = dTDP-4-dehydro-6-deoxy-α-D-allose
Other name(s): dTDP-deoxyglucose 3-epimerase; dTDP-4-keto-6-deoxy-D-glucose 3-epimerase; dTDP-4-keto-6-deoxyglucose 3-epimerase; gerF (gene name); tylJ (gene name); chmJ (gene name); mydH (gene name)
Systematic name: dTDP-4-dehydro-6-deoxy-α-D-glucose 3-epimerase
Comments: The enzyme is involved in the biosynthetic pathway of dTDP-6-deoxy-α-D-allose, which is converted to mycinose after attachment to the aglycones of several macrolide antibiotics, including tylosin, chalcomycin, dihydrochalcomycin, and mycinamicin II.
Links to other databases: BRENDA, EXPASY, KEGG, Metacyc, PDB, CAS registry number:
References:
1. Sohng, J.K., Kim, H.J., Nam, D.H., Lim, D.O., Han, J.M., Lee, H.J. and Yoo, J.C. Cloning, expression, and biological function of a dTDP-deoxyglucose epimerase (gerF) gene from Streptomyces sp. GERI-155. Biotechnol. Lett. 26 (2004) 185-191. [PMID: 15049360]
2. Thuy, T.T., Liou, K., Oh, T.J., Kim, D.H., Nam, D.H., Yoo, J.C. and Sohng, J.K. Biosynthesis of dTDP-6-deoxy-β-D-allose, biochemical characterization of dTDP-4-keto-6-deoxyglucose reductase (GerKI) from Streptomyces sp. KCTC 0041BP. Glycobiology 17 (2007) 119-126. [PMID: 17053005]
3. Kubiak, R.L., Phillips, R.K., Zmudka, M.W., Ahn, M.R., Maka, E.M., Pyeatt, G.L., Roggensack, S.J. and Holden, H.M. Structural and functional studies on a 3′-epimerase involved in the biosynthesis of dTDP-6-deoxy-D-allose. Biochemistry 51 (2012) 9375-9383. [PMID: 23116432]
Accepted name: UDP-N-acetyl-L-fucosamine synthase
Reaction: UDP-2-acetamido-2,6-dideoxy-β-L-talose = UDP-N-acetyl-β-L-fucosamine
For diagram of reaction click here.
Glossary: UDP-2-acetamido-2,6-dideoxy-β-L-talose = UDP-N-acetyl-β-L-pneumosamine
Other name(s): WbjD; Cap5G
Systematic name: UDP-2-acetamido-2,6-dideoxy-L-talose 2-epimerase
Comments: Isolated from the bacteria Pseudomonas aeruginosa and Staphylococcus aureus. Involved in bacterial polysaccharide biosynthesis.
Links to other databases: BRENDA, EXPASY, KEGG, MetaCyc, CAS registry number:
References:
1. Kneidinger, B., O'Riordan, K., Li, J., Brisson, J.R., Lee, J.C. and Lam, J.S. Three highly conserved proteins catalyze the conversion of UDP-N-acetyl-D-glucosamine to precursors for the biosynthesis of O antigen in Pseudomonas aeruginosa O11 and capsule in Staphylococcus aureus type 5. Implications for the UDP-N-acetyl-L-fucosamine biosynthetic pathway. J. Biol. Chem. 278 (2003) 3615-3627. [PMID: 12464616]
2. Mulrooney, E.F., Poon, K.K., McNally, D.J., Brisson, J.R. and Lam, J.S. Biosynthesis of UDP-N-acetyl-L-fucosamine, a precursor to the biosynthesis of lipopolysaccharide in Pseudomonas aeruginosa serotype O11. J. Biol. Chem. 280 (2005) 19535-19542. [PMID: 15778500]
Accepted name: L-fucose mutarotase
Reaction: α-L-fucopyranose = β-L-fucopyranose
For diagram of reaction click here
Other name(s): FucU; fucose mutarotase; FucM
Systematic name: L-fucose 1-epimerase
Comments: This enzyme shows no 1-epimerase activity with D-glucose, L-rhamnose and D-fucose (cf. EC 5.1.3.3, aldose 1-epimerase) [1].
Links to other databases: BRENDA, EXPASY, KEGG, Metacyc, PDB, CAS registry number:
References:
1. Ryu, K.S., Kim, C., Kim, I., Yoo, S., Choi, B.S. and Park, C. NMR application probes a novel and ubiquitous family of enzymes that alter monosaccharide configuration. J. Biol. Chem. 279 (2004) 25544-25548. [PMID: 15060078]
2. Park, D., Ryu, K.S., Choi, D., Kwak, J. and Park, C. Characterization and role of fucose mutarotase in mammalian cells. Glycobiology 17 (2007) 955-962. [PMID: 17602138]
Accepted name: D-psicose 3-epimerase
Reaction: D-psicose = D-fructose
Glossary: D-psicose = D-ribo-hex-2-ulose = D-allulose
Other name(s): DPEase (ambiguous)
Systematic name: D-psicose 3-epimerase
Comments: The enzyme is highly specific for D-psicose and shows very low activity with D-tagatose (cf. EC 5.1.3.31, D-tagatose 3-epimerase). The enzyme from the bacterium Clostridium scindens requires Mn2+ [1], whereas the enzymes from the bacteria Clostridium cellulolyticum [2,5], Clostridium sp. BNL1100 [3], and Clostridium bolteae [4] require Co2+ as optimum cofactor. The enzyme from Ruminococcus sp. [6] is not dependent on the presence of metal ions, but its activity is enhanced by Mn2+.
Links to other databases: BRENDA, EXPASY, KEGG, Metacyc, PDB, CAS registry number:
References:
1. Mu, W., Chu, F., Xing, Q., Yu, S., Zhou, L. and Jiang, B. Cloning, expression, and characterization of a D-psicose 3-epimerase from Clostridium cellulolyticum H10. J. Agric. Food Chem. 59 (2011) 7785-7792. [PMID: 21663329]
2. Chan, H.C., Zhu, Y., Hu, Y., Ko, T.P., Huang, C.H., Ren, F., Chen, C.C., Ma, Y., Guo, R.T. and Sun, Y. Crystal structures of D-psicose 3-epimerase from Clostridium cellulolyticum H10 and its complex with ketohexose sugars. Protein Cell 3 (2012) 123-131. [PMID: 22426981]
3. Zhu, Y., Men, Y., Bai, W., Li, X., Zhang, L., Sun, Y. and Ma, Y. Overexpression of D-psicose 3-epimerase from Ruminococcus sp. in Escherichia coli and its potential application in D-psicose production. Biotechnol. Lett. 34 (2012) 1901-1906. [PMID: 22760176]
4. Zhang, W., Fang, D., Xing, Q., Zhou, L., Jiang, B. and Mu, W. Characterization of a novel metal-dependent D-psicose 3-epimerase from Clostridium scindens 35704. PLoS One 8 (2013) e62987. [PMID: 23646168]
5. Mu, W., Zhang, W., Fang, D., Zhou, L., Jiang, B. and Zhang, T. Characterization of a D-psicose-producing enzyme, D-psicose 3-epimerase, from Clostridium sp. Biotechnol. Lett. 35 (2013) 1481-1486. [PMID: 23660703]
6. Jia, M., Mu, W., Chu, F., Zhang, X., Jiang, B., Zhou, L.L. and Zhang, T. A D-psicose 3-epimerase with neutral pH optimum from Clostridium bolteae for D-psicose production: cloning, expression, purification, and characterization. Appl. Microbiol. Biotechnol. 98 (2014) 717-725. [PMID: 23644747]
Accepted name: D-tagatose 3-epimerase
Reaction: (1) D-tagatose = D-sorbose
(2) D-psicose = D-fructose
For diagram of reaction click here.
Glossary: D-psicose = D-ribo-hex-2-ulose
Other name(s): L-ribulose 3-epimerase; ketose 3-epimerase
Systematic name: D-tagatose 3-epimerase
Comments: The enzymes isolated from the bacteria Pseudomonas cichorii [2], Pseudomonas sp. ST-24 [1], Rhodobacter sphaeroides [3] and Mesorhizobium loti [4] catalyse the epimerization of various ketoses at the C3 position, interconverting D-fructose and D-psicose, D-tagatose and D-sorbose, D-ribulose and D-xylulose, and L-ribulose and L-xylulose. The specificity depends on the species. The enzymes from Pseudomonas cichorii and Rhodobacter sphaeroides require Mn2+ [2,3].
Links to other databases: BRENDA, EXPASY, KEGG, Metacyc, PDB, CAS registry number:
References:
1. Itoh, H., Okaya, H., Khan, A. R., Tajima, S., Hayakawa, S., Izumori, K. Purification and characterization of D-tagatose 3-epimerase from Pseudomonas sp. ST-24. Biosci. Biotechnol. Biochem. 58 (1994) 2168-2171.
2. Yoshida, H., Yamada, M., Nishitani, T., Takada, G., Izumori, K. and Kamitori, S. Crystal structures of D-tagatose 3-epimerase from Pseudomonas cichorii and its complexes with D-tagatose and D-fructose. J. Mol. Biol. 374 (2007) 443-453. [PMID: 17936787]
3. Zhang, L., Mu, W., Jiang, B. and Zhang, T. Characterization of D-tagatose-3-epimerase from Rhodobacter sphaeroides that converts D-fructose into D-psicose. Biotechnol. Lett. 31 (2009) 857-862. [PMID: 19205890]
4. Uechi, K., Takata, G., Fukai, Y., Yoshihara, A. and Morimoto, K. Gene cloning and characterization of L-ribulose 3-epimerase from Mesorhizobium loti and its application to rare sugar production. Biosci. Biotechnol. Biochem. 77 (2013) 511-515. [PMID: 23470755]
Accepted name: L-rhamnose mutarotase
Reaction: α-L-rhamnopyranose = β-L-rhamnopyranose
Other name(s): rhamnose 1-epimerase; type-3 mutarotase; YiiL
Systematic name: L-rhamnopyranose 1-epimerase
Comments: The enzyme is specific for L-rhamnopyranose.
Links to other databases: BRENDA, EXPASY, KEGG, Metacyc, PDB, CAS registry number:
References:
1. Ryu, K.S., Kim, C., Kim, I., Yoo, S., Choi, B.S. and Park, C. NMR application probes a novel and ubiquitous family of enzymes that alter monosaccharide configuration. J. Biol. Chem. 279 (2004) 25544-25548. [PMID: 15060078]
2. Ryu, K.S., Kim, J.I., Cho, S.J., Park, D., Park, C., Cheong, H.K., Lee, J.O. and Choi, B.S. Structural insights into the monosaccharide specificity of Escherichia coli rhamnose mutarotase. J. Mol. Biol. 349 (2005) 153-162. [PMID: 15876375]
Accepted name: 2-epi-5-epi-valiolone epimerase
Reaction: 2-epi-5-epi-valiolone = 5-epi-valiolone
For diagram of reaction click here.
Glossary: 2-epi-5-epi-valiolone= (2S,3S,4S,5R)-2,3,4,5-tetrahydroxy-5-(hydroxymethyl)cyclohexanone
5-epi-valiolone = (2R,3S,4S,5R)-2,3,4,5-tetrahydroxy-5-(hydroxymethyl)cyclohexanone
Other name(s): CetB; EVE
Systematic name: 2-epi-5-epi-valiolone 2-epimerase
Comments: The enzyme, characterized from the bacterium Actinomyces sp. Lu 9419, is involved in the biosynthesis of the antitumor agent cetoniacytone A.
Links to other databases: BRENDA, EXPASY, KEGG, MetaCyc, CAS registry number:
References:
1. Wu, X., Flatt, P.M., Xu, H. and Mahmud, T. Biosynthetic gene cluster of cetoniacytone A, an unusual aminocyclitol from the endosymbiotic Bacterium Actinomyces sp. Lu 9419. Chembiochem 10 (2009) 304-314. [PMID: 19101977]
Accepted name: monoglucosyldiacylglycerol epimerase
Reaction: a 1,2-diacyl-3-O-(β-D-glucopyranosyl)-sn-glycerol = a 1,2-diacyl-3-O-(β-D-galactopyranosyl)-sn-glycerol
Glossary: a 1,2-diacyl-3-O-(β-D-glucopyranosyl)-sn-glycerol = β-monoglucosyldiacylglycerol = GlcDG
a 1,2-diacyl-3-O-(β-D-galactopyranosyl)-sn-glycerol = β-monogalactosyldiacylglycerol = MGDG
Other name(s): glucolipid epimerase; mgdE (gene name)
Systematic name: 1,2-diacyl-3-O-(β-D-glucopyranosyl)-sn-glycerol 4-epimerase
Comments: The enzyme, characterized from cyanobacteria, is involves in the biosynthesis of galactolipids found in their photosynthetic membranes.
Links to other databases: BRENDA, EXPASY, KEGG, MetaCyc, CAS registry number:
References:
1. Sato, N. and Murata, N. Lipid biosynthesis in the blue-green alga, Anabaena variabilis II. Fatty acids and lipid molecular species. Biochim. Biophys. Acta 710 (1982) 279-289.
2. Awai, K., Ohta, H. and Sato, N. Oxygenic photosynthesis without galactolipids. Proc. Natl. Acad. Sci. USA 111 (2014) 13571-13575. [PMID: 25197079]
Accepted name: 2-epi-5-epi-valiolone 7-phosphate 2-epimerase
Reaction: 2-epi-5-epi-valiolone 7-phosphate = 5-epi-valiolone 7-phosphate
For diagram of reaction click here.
Glossary: 2-epi-5-epi-valiolone 7-phosphate = (2S,3S,4S,5R)-2,3,4,5-tetrahydroxy-5-(phosphonooxymethyl)cyclohexanone = (2S,3S,4S,5R)-2,3,4,5-tetrahydroxy-5-(phosphooxymethyl)cyclohexanone
5-epi-valiolone 7-phosphate = (2R,3S,4S,5R)-2,3,4,5-tetrahydroxy-5-(phosphonooxymethyl)cyclohexanone = (2R,3S,4S,5R)-2,3,4,5-tetrahydroxy-5-(phosphooxymethyl)cyclohexanone
Other name(s): AcbO
Systematic name: 2-epi-5-epi-valiolone-7-phosphate 2-epimerase
Comments: The enzyme, isolated from the bacterium Actinoplanes sp. SE 50/110, is involved in the biosynthesis of the α-glucosidase inhibitor acarbose.
Links to other databases: BRENDA, EXPASY, KEGG, MetaCyc, CAS registry number:
References:
1. Zhang, C.S., Podeschwa, M., Altenbach, H.J., Piepersberg, W. and Wehmeier, U.F. The acarbose-biosynthetic enzyme AcbO from Actinoplanes sp. SE 50/110 is a 2-epi-5-epi-valiolone-7-phosphate 2-epimerase. FEBS Lett. 540 (2003) 47-52. [PMID: 12681481]
Accepted name: heparosan-glucuronate 5-epimerase
Reaction: [heparosan]-D-glucuronate = [acharan]-L-iduronate
Glossary: acharan = [GlcNAc-α-(1→4)-IdoA-α-(1→4)]n
heparosan = [GlcNAc-α-(1→4)-GlcA-β-(1→4)]n
Other name(s): HG-5epi
Systematic name: [heparosan]-D-glucuronate 5-epimerase
Comments: The enzyme, characterized from the giant African snail Achatina fulica, participates in the biosynthetic pathway of acharan sulfate. Unlike EC 5.1.3.17, heparosan-N-sulfate-glucuronate 5-epimerase, it shows no activity with D-glucuronate residues in heparosan-N-sulfate.
Links to other databases: BRENDA, EXPASY, KEGG, MetaCyc, CAS registry number:
References:
1. Mochizuki, H., Yamagishi, K., Suzuki, K., Kim, Y.S. and Kimata, K. Heparosan-glucuronate 5-epimerase: Molecular cloning and characterization of a novel enzyme. Glycobiology 25 (2015) 735-744. [PMID: 25677302]
Accepted name: mannuronan 5-epimerase
Reaction: [mannuronan]-β-D-mannuronate = [alginate]-α-L-guluronate
Glossary: mannuronan = a linear polymer of β-D-mannuronate residues linked by (1-4) linkages
alginate = a linear polymer of β-D-mannuronate residues linked by (1-4) linkages, with variable amounts of its C-5 epimer α-L-glucuronate.
Other name(s): algG (gene name); alginate epimerase; C5-mannuronan epimerase; mannuronan C-5-epimerase
Systematic name: [mannuronan]-β-D-mannuronate 5-epimerase
Comments: The enzyme epimerizes the C-5 bond in some β-D-mannuronate residues in mannuronan, converting them to α-L-guluronate residues, and thus modifying the mannuronan into alginate. It is found in brown algae and alginate-producing bacterial species from the Pseudomonas and Azotobacter genera.
Links to other databases: BRENDA, EXPASY, KEGG, MetaCyc, PDB, CAS registry number:
References:
1. Franklin, M.J., Chitnis, C.E., Gacesa, P., Sonesson, A., White, D.C. and Ohman, D.E. Pseudomonas aeruginosa AlgG is a polymer level alginate C5-mannuronan epimerase. J. Bacteriol. 176 (1994) 1821-1830. [PMID: 8144447]
2. Morea, A., Mathee, K., Franklin, M.J., Giacomini, A., O'Regan, M. and Ohman, D.E. Characterization of algG encoding C5-epimerase in the alginate biosynthetic gene cluster of Pseudomonas fluorescens. Gene 278 (2001) 107-114. [PMID: 11707327]
3. Nyvall, P., Corre, E., Boisset, C., Barbeyron, T., Rousvoal, S., Scornet, D., Kloareg, B. and Boyen, C. Characterization of mannuronan C-5-epimerase genes from the brown alga Laminaria digitata. Plant Physiol. 133 (2003) 726-735. [PMID: 14526115]
4. Jain, S., Franklin, M.J., Ertesvag, H., Valla, S. and Ohman, D.E. The dual roles of AlgG in C-5-epimerization and secretion of alginate polymers in Pseudomonas aeruginosa. Mol. Microbiol. 47 (2003) 1123-1133. [PMID: 12581364]
5. Douthit, S.A., Dlakic, M., Ohman, D.E. and Franklin, M.J. Epimerase active domain of Pseudomonas aeruginosa AlgG, a protein that contains a right-handed β-helix. J. Bacteriol. 187 (2005) 4573-4583. [PMID: 15968068]
6. Wolfram, F., Kitova, E.N., Robinson, H., Walvoort, M.T., Codee, J.D., Klassen, J.S. and Howell, P.L. Catalytic mechanism and mode of action of the periplasmic alginate epimerase AlgG. J. Biol. Chem. 289 (2014) 6006-6019. [PMID: 24398681]
Accepted name: D-erythrulose 1-phosphate 3-epimerase
Reaction: D-erythrulose 1-phosphate = L-erythrulose 1-phosphate
Other name(s): eryC (gene name)
Systematic name: D-erythrulose-1-phosphate 3-epimerase
Comments: The enzyme, characterized from the pathogenic bacterium Brucella abortus, which causes brucellosis in livestock, participates in erythritol catabolism.
Links to other databases: BRENDA, EXPASY, KEGG, MetaCyc, CAS registry number:
References:
1. Barbier, T., Collard, F., Zuniga-Ripa, A., Moriyon, I., Godard, T., Becker, J., Wittmann, C., Van Schaftingen, E. and Letesson, J.J. Erythritol feeds the pentose phosphate pathway via three new isomerases leading to D-erythrose-4-phosphate in Brucella. Proc. Natl. Acad. Sci. USA 111 (2014) 17815-17820. [PMID: 25453104]
[EC 5.1.3.39 Deleted entry: L-erythrulose 4-phosphate epimerase. The activity has been shown not to take place. (EC 5.1.3.39 created 2016, deleted 2018)]
Accepted name: D-tagatose 6-phosphate 4-epimerase
Reaction: D-tagatose 6-phosphate = D-fructose 6-phosphate
For diagram of reaction click here.
Systematic name: D-tagatose 6-phosphate 4-epimerase
Comments: The enzyme from Agrobacterium fabrum C58 is part of D-altritol and galactitol degradation pathways.
Links to other databases: BRENDA, EXPASY, KEGG, MetaCyc, CAS registry number:
References:
1. Wichelecki, D.J., Vetting, M.W., Chou, L., Al-Obaidi, N., Bouvier, J.T., Almo, S.C. and Gerlt, J.A. ATP-binding cassette (ABC) transport system solute-binding protein-guided identification of novel D-altritol and galactitol catabolic pathways in Agrobacterium tumefaciens C58. J. Biol. Chem. 290 (2015) 28963-28976. [PMID: 26472925]
Accepted name: fructoselysine 3-epimerase
Reaction: N6-(D-fructosyl)-L-lysine = N6-(D-psicosyl)-L-lysine
Other name(s): frlC (gene name)
Systematic name: D-fructosyl-L-lysine 3-epimerase
Comments: The enzyme, characterized from the bacterium Escherichia coli, is involved in the catabolism of fructoseamines, amino acid sugar complexes that are formed non-enzymically.
Links to other databases: BRENDA, EXPASY, KEGG, MetaCyc, CAS registry number:
References:
1. Wiame, E. and Van Schaftingen, E. Fructoselysine 3-epimerase, an enzyme involved in the metabolism of the unusual Amadori compound psicoselysine in Escherichia coli. Biochem. J. 378 (2004) 1047-1052. [PMID: 14641112]
Accepted name: D-glucosamine-6-phosphate 4-epimerase
Reaction: D-glucosamine 6-phosphate = D-galactosamine 6-phosphate
For diagram of reaction click here.
Other name(s): ST2245 (locus name)
Systematic name: D-glucosamine 6-phosphate 4-epimerase
Comments: The enzyme, characterized from the archaeon Sulfolobus tokodaii, participates in a pathway for the biosynthesis of UDP-N-acetyl-α-D-galactosamine.
Links to other databases: BRENDA, EXPASY, KEGG, Metacyc, CAS registry number:
References:
1. Dadashipour, M., Iwamoto, M., Hossain, M.M., Akutsu, J.I., Zhang, Z. and Kawarabayasi, Y. Identification of a direct biosynthetic pathway for UDP-N-acetylgalactosamine from glucosamine-6-phosphate in thermophilic crenarchaeon Sulfolobus tokodaii. J. Bacteriol. 200 (2018) . [PMID: 29507091]
Accepted name: sulfoquinovose mutarotase
Reaction: 6-sulfo-α-D-quinovose = 6-sulfo-β-D-quinovose
Systematic name: 6-sulfo-D-quinovose 1-epimerase
Comments: The enzyme is found in bacteria that possess sulfoglycolytic pathways. The enzyme can also act on other aldohexoses such as D-galactose, D-glucose, D-glucose-6-phosphate, and D-glucuronate, but with lower efficiency. Does not act on D-mannose.
Links to other databases: BRENDA, EXPASY, ExplorEnz, KEGG, MetaCyc, CAS registry number:
References:
1. Abayakoon, P., Lingford, J.P., Jin, Y., Bengt, C., Davies, G.J., Yao, S., Goddard-Borger, E.D. and Williams, S.J. Discovery and characterization of a sulfoquinovose mutarotase using kinetic analysis at equilibrium by exchange spectroscopy. Biochem. J. 475 (2018) 1371-1383. [PMID: 29535276]
Accepted name: mannose 2-epimerase
Reaction: β-D-mannopyranose = β-D-glucopyranose
Systematic name: β-D-mannopyranose 2-epimerase
Comments: The enzyme, characterized from multiple bacterial species, catalyses the interconversion between β-D-glucopyranose and β-D-mannopyranose through proton abstraction-addition at the C2 position.
Links to other databases: BRENDA, EXPASY, KEGG, MetaCyc, CAS registry number:
References:
1. Saburi, W., Sato, S., Hashiguchi, S., Muto, H., Iizuka, T. and Mori, H. Enzymatic characteristics of D-mannose 2-epimerase, a new member of the acylglucosamine 2-epimerase superfamily. Appl. Microbiol. Biotechnol. 103 (2019) 6559-6570. [PMID: 31201453]
Accepted name: methylmalonyl-CoA epimerase
Reaction: (R)-methylmalonyl-CoA = (S)-methylmalonyl-CoA
For diagram of reaction click here (another example).
Other name(s): methylmalonyl-CoA racemase; methylmalonyl coenzyme A racemase; DL-methylmalonyl-CoA racemase; 2-methyl-3-oxopropanoyl-CoA 2-epimerase [incorrect]
Systematic name: methylmalonyl-CoA 2-epimerase
Links to other databases: BRENDA, EXPASY, GTD, KEGG, Metacyc, PDB, CAS registry number: 9024-03-7
References:
1. Mazumder, R., Sasakawa, T., Kaziro, Y. and Ochoa, S. Metabolism of propionic acid in animal tissues. IX. Methylmalonyl coenzyme A racemase. J. Biol. Chem. 237 (1962) 3065-3068.
2. Overath, P., Kellerman, G.M., Lynen, F., Fritz, H.P. and Keller, H.J. Zum Mechanismus der Umlagerung von Methylmalonyl-CoA in Succinyl-CoA. II. Versuche zur Wirkungsweise von Methylmalonyl-CoA-Isomerase and Methylmalonyl-CoA-Racemase. Biochem. Z. 335 (1962) 500-518.
Accepted name: 16-hydroxysteroid epimerase
Reaction: 16α-hydroxysteroid = 16β-hydroxysteroid
Systematic name: 16-hydroxysteroid 16-epimerase
Links to other databases: BRENDA, EXPASY, KEGG, Metacyc, CAS registry number: 37318-40-4
References:
1. Dahm, K., Lindlau, M. and Breuer, H. Steroid epimerase-a new enzyme of estrogen metabolism. Biochim. Biophys. Acta 159 (1968) 377-389. [PMID: 5657462]
Accepted name: allantoin racemase
Reaction: (S)(+)-allantoin = (R)(–)-allantoin
For diagram click here.
Systematic name: allantoin racemase
Links to other databases: BRENDA, EXPASY, KEGG, Metacyc, PDB, CAS registry number: 56214-40-5
References:
1. van der Drift, L., Vogels, G.D. and van der Drift, C. Allantoin racemase: a new enzyme from Pseudomonas species. Biochim. Biophys. Acta 391 (1975) 240-248. [PMID: 237557]
Accepted name: α-methylacyl-CoA racemase
Reaction: (2S)-2-methylacyl-CoA = (2R)-2-methylacyl-CoA
For diagram click here.
Systematic name: 2-methylacyl-CoA 2-epimerase
Comments: α-methyl-branched acyl-CoA derivatives with chain lengths of more than C10 are substrates. Also active towards some aromatic compounds (e.g. ibuprofen) and bile acid intermediates, such as trihydroxycoprostanoyl-CoA. Not active towards free acids
Links to other databases: BRENDA, EXPASY, KEGG, Metacyc, PDB, CAS registry number: 156681-44-6
References:
1. Schmitz, W., Fingerhut, R., Conzelmann, E. Purification and properties of an α-methylacyl-CoA racemase from rat liver. Eur. J. Biochem. 222 (1994) 313-323. [PMID: 8020470]
Accepted name: hydantoin racemase
Reaction: D-5-monosubstituted hydantoin = L-5-monosubstituted hydantoin
Glossary: hydantoin = imidazolidine-2,4-dione
Other name(s): 5'-monosubstituted-hydantoin racemase; HyuA; HyuE;
Systematic name: D-5-monosubstituted-hydantoin racemase
Comments: This enzyme, along with N-carbamoylase (EC 3.5.1.77 and EC 3.5.1.87) and hydantoinase, forms part of the reaction cascade known as the "hydantoinase process", which allows the total conversion of D,L-5-monosubstituted hydantoins into optically pure D- or L-amino acids [7]. The enzyme from Pseudomonas sp. (HyuE) has a preference for hydantoins with aliphatic substituents, e.g. D- and L-5-[2-(methylsulfanyl)ethyl]hydantoin, whereas that from Arthrobacter aurescens shows highest activity with arylalkyl substituents, especially 5-benzylhydantoin, at the 5-position [2]. In the enzyme from Sinorhizobium meliloti, Cys76 is responsible for recognition and proton retrieval of D-isomers, while Cys181 is responsible for L-isomer recognition and racemization [6].
Links to other databases: BRENDA, EXPASY, KEGG, Metacyc, CAS registry number:
References:
1. Watabe, K., Ishikawa, T., Mukohara, Y. and Nakamura, H. Purification and characterization of the hydantoin racemase of Pseudomonas sp. strain NS671 expressed in Escherichia coli. J. Bacteriol. 174 (1992) 7989-7995. [PMID: 1459947]
2. Wiese, A., Pietzsch, M., Syldatk, C., Mattes, R. and Altenbuchner, J. Hydantoin racemase from Arthrobacter aurescens DSM 3747: heterologous expression, purification and characterization. J. Biotechnol. 80 (2000) 217-230. [PMID: 10949312]
3. Martínez-Rodríguez, S., Las Heras-Vázquez, F.J., Mingorance-Cazorla, L., Clemente-Jiménez, J.M. and Rodríguez-Vico, F. Molecular cloning, purification, and biochemical characterization of hydantoin racemase from the legume symbiont Sinorhizobium meliloti CECT 4114. Appl. Environ. Microbiol. 70 (2004) 625-630. [PMID: 14711700]
4. Martínez-Rodríguez, S., Las Heras-Vázquez, F.J., Clemente-Jiménez, J.M. and Rodríguez-Vico, F. Biochemical characterization of a novel hydantoin racemase from Agrobacterium tumefaciens C58. Biochimie 86 (2004) 77-81. [PMID: 15016445]
5. Suzuki, S., Onishi, N. and Yokozeki, K. Purification and characterization of hydantoin racemase from Microbacterium liquefaciens AJ 3912. Biosci. Biotechnol. Biochem. 69 (2005) 530-536. [PMID: 15784981]
6. Martínez-Rodríguez, S., Andújar-Sánchez, M., Neira, J.L., Clemente-Jiménez, J.M., Jara-Pérez, V., Rodríguez-Vico, F. and Las Heras-Vázquez, F.J. Site-directed mutagenesis indicates an important role of cysteines 76 and 181 in the catalysis of hydantoin racemase from Sinorhizobium meliloti. Protein Sci. 15 (2006) 2729-2738. [PMID: 17132860]
7. Altenbuchner, J., Siemann-Herzberg, M. and Syldatk, C. Hydantoinases and related enzymes as biocatalysts for the synthesis of unnatural chiral amino acids. Curr. Opin. Biotechnol. 12 (2001) 559-563. [PMID: 11849938]
Accepted name: NAD(P)H-hydrate epimerase
Reaction: (1) (6R)-6β-hydroxy-1,4,5,6-tetrahydronicotinamide-adenine dinucleotide = (6S)-6β-hydroxy-1,4,5,6-tetrahydronicotinamide-adenine dinucleotide
(2) (6R)-6β-hydroxy-1,4,5,6-tetrahydronicotinamide-adenine dinucleotide phosphate = (6S)-6β-hydroxy-1,4,5,6-tetrahydronicotinamide-adenine dinucleotide phosphate
Glossary: 6β-hydroxy-1,4,5,6-tetrahydronicotinamide-adenine dinucleotide = NADHX = NADH-hydrate
6β-hydroxy-1,4,5,6-tetrahydronicotinamide-adenine dinucleotide phosphate = NADPHX = NADPH-hydrate
Other name(s): NAD(P)HX epimerase
Systematic name: (6R)-6β-hydroxy-1,4,5,6-tetrahydronicotinamide-adenine dinucleotide 6-epimerase
Comments: The enzyme can use either (R)-NADH-hydrate or (R)-NADPH-hydrate as a substrate. Its physiological role is to convert the (R) forms to the (S) forms, which could then be restored to active dinucleotides by EC 4.2.1.93, ATP-dependent NAD(P)H-hydrate dehydratase.
Links to other databases: BRENDA, EXPASY, KEGG, Metacyc, PDB, CAS registry number:
References:
1. Marbaix, A.Y., Noel, G., Detroux, A.M., Vertommen, D., Van Schaftingen, E. and Linster, C.L. Extremely conserved ATP- or ADP-dependent enzymatic system for nicotinamide nucleotide repair. J. Biol. Chem. 286 (2011) 41246-41252. [PMID: 21994945]
Accepted name: dihydroneopterin triphosphate 2'-epimerase
Reaction: 7,8-dihydroneopterin 3'-triphosphate = 7,8-dihydromonapterin 3'-triphosphate
For diagram of reaction click here.
Glossary: 7,8-dihydroneopterin 3'-triphosphate = (2R,3S)-3-(2-amino-4-oxo-3,4,7,8-tetrahydropteridin-6-yl)-2,3-dihydroxypropyl triphosphate
7,8-dihydromonapterin 3'-triphosphate = (2S,3S)-3-(2-amino-4-oxo-3,4,7,8-tetrahydropteridin-6-yl)-2,3-dihydroxypropyl triphosphate
Other name(s): D-erythro-7,8-dihydroneopterin triphosphate epimerase; folX (gene name)
Systematic name: 7,8-dihydroneopterin 3'-triphosphate 2'-epimerase
Comments: The enzyme, found in gammaproteobacteria, has almost no activity with 7,8-dihydroneopterin [2].
Links to other databases: BRENDA, EXPASY, KEGG, MetaCyc, PDB, CAS registry number:
References:
1. Ahn, C., Byun, J. and Yim, J. Purification, cloning, and functional expression of dihydroneopterin triphosphate 2'-epimerase from Escherichia coli. J. Biol. Chem. 272 (1997) 15323-15328. [PMID: 9182560]
2. Haussmann, C., Rohdich, F., Schmidt, E., Bacher, A. and Richter, G. Biosynthesis of pteridines in Escherichia coli. Structural and mechanistic similarity of dihydroneopterin-triphosphate epimerase and dihydroneopterin aldolase. J. Biol. Chem. 273 (1998) 17418-17424. [PMID: 9651328]
Accepted name: 7,8-dihydroneopterin epimerase
Reaction: 7,8-dihydroneopterin = 7,8-dihydromonapterin
Glossary: 7,8-dihydroneopterin = 2-amino-6-[(1S,2R)-1,2,3-trihydroxypropyl]-7,8-dihydropteridin-4(3H)-one
7,8-dihydromonapterin = 2-amino-6-[(1S,2S)-1,2,3-trihydroxypropyl]-7,8-dihydropteridin-4(3H)-one
Systematic name: 7,8-dihydroneopterin 2'-epimerase
Comments: The enzyme, which has been characterized in bacteria and plants, also has the activity of EC 4.1.2.25, dihydroneopterin aldolase. The enzyme from the bacterium Mycobacterium tuberculosis has an additional oxygenase function (EC 1.13.11.81, 7,8-dihydroneopterin oxygenase) [4].
Links to other databases: BRENDA, EXPASY, KEGG, MetaCyc, PDB, CAS registry number:
References:
1. Haussmann, C., Rohdich, F., Schmidt, E., Bacher, A. and Richter, G. Biosynthesis of pteridines in Escherichia coli. Structural and mechanistic similarity of dihydroneopterin-triphosphate epimerase and dihydroneopterin aldolase. J. Biol. Chem. 273 (1998) 17418-17424. [PMID: 9651328]
2. Goyer, A., Illarionova, V., Roje, S., Fischer, M., Bacher, A. and Hanson, A.D. Folate biosynthesis in higher plants. cDNA cloning, heterologous expression, and characterization of dihydroneopterin aldolases. Plant Physiol. 135 (2004) 103-111. [PMID: 15107504]
3. Czekster, C.M. and Blanchard, J.S. One substrate, five products: reactions catalyzed by the dihydroneopterin aldolase from Mycobacterium tuberculosis. J. Am. Chem. Soc. 134 (2012) 19758-19771. [PMID: 23150985]
4. Blaszczyk, J., Lu, Z., Li, Y., Yan, H. and Ji, X. Crystallographic and molecular dynamics simulation analysis of Escherichia coli dihydroneopterin aldolase. Cell Biosci 4 (2014) 52. [PMID: 25264482]