Enzyme Nomenclature

EC 5.1 Racemases and Epimerases

Sections

EC 5.1.1 Acting on Amino Acids and Derivatives
EC 5.1.2 Acting on Hydroxy Acids and Derivatives
EC 5.1.3 Acting on Carbohydrates and Derivatives
EC 5.1.99 Acting on Other Compounds


EC 5.1.1 Acting on Amino Acids and Derivatives

Contents

EC 5.1.1.1 alanine racemase
EC 5.1.1.2 methionine racemase
EC 5.1.1.3 glutamate racemase
EC 5.1.1.4 proline racemase
EC 5.1.1.5 lysine racemase
EC 5.1.1.6 threonine racemase
EC 5.1.1.7 diaminopimelate epimerase
EC 5.1.1.8 4-hydroxyproline epimerase
EC 5.1.1.9 arginine racemase
EC 5.1.1.10 amino-acid racemase
EC 5.1.1.11 phenylalanine racemase (ATP-hydrolysing)
EC 5.1.1.12 ornithine racemase
EC 5.1.1.13 aspartate racemase
EC 5.1.1.14 nocardicin-A epimerase
EC 5.1.1.15 2-aminohexano-6-lactam racemase
EC 5.1.1.16 protein-serine epimerase
EC 5.1.1.17 isopenicillin-N epimerase
EC 5.1.1.18 serine racemase
EC 5.1.1.19 O-ureido-serine racemase
EC 5.1.1.20 L-Ala-D/L-Glu epimerase
EC 5.1.1.21 isoleucine 2-epimerase

Entries

EC 5.1.1.1

Accepted name: alanine racemase

Reaction: L-alanine = D-alanine

Other name(s): L-alanine racemase

Systematic name: alanine racemase

Comments: A pyridoxal-phosphate protein.

Links to other databases: BRENDA, EXPASY, GTD, KEGG, Metacyc, PDB, CAS registry number: 9024-06-0

References:

1. Marr, A.G. and Wilson, P.W. The alanine racemase of Brucella abortus. Arch. Biochem. Biophys. 49 (1954) 424-433.

2. Wood, W.A. Amino acid racemases. Methods Enzymol. 2 (1955) 212-217.

3. Wood, W.A. and Gunsalus, I.C. D-Alanine formation: a racemase in Streptococcus faecalis. J. Biol. Chem. 190 (1951) 403-416.

[EC 5.1.1.1 created 1961]

EC 5.1.1.2

Accepted name: methionine racemase

Reaction: L-methionine = D-methionine

Systematic name: methionine racemase

Comments: A pyridoxal-phosphate protein.

Links to other databases: BRENDA, EXPASY, KEGG, Metacyc, CAS registry number: 9024-07-1

References:

1. Kallio, R.E. and Larson, A.D. Methionine degradation by a species of Pseudomonas, in McElroy, W.D. and Glass, H.B. (Eds.), A Symposium on Amino Acid Metabolism, Johns Hopkins Press, Baltimore, 1955, pp. 616-634.

[EC 5.1.1.2 created 1961]

EC 5.1.1.3

Accepted name: glutamate racemase

Reaction: L-glutamate = D-glutamate

Systematic name: glutamate racemase

Comments: A pyridoxal-phosphate protein.

Links to other databases: BRENDA, EXPASY, GTD, KEGG, Metacyc, PDB, CAS registry number: 9024-08-2

References:

1. Glaser, L. Glutamic acid racemase from Lactobacillus arabinosus. J. Biol. Chem. 235 (1960) 2095-2098.

[EC 5.1.1.3 created 1961]

EC 5.1.1.4

Accepted name: proline racemase

Reaction: L-proline = D-proline

Systematic name: proline racemase

Links to other databases: BRENDA, EXPASY, KEGG, Metacyc, PDB, CAS registry number: 9024-09-3

References:

1. Stadtman, T.C. and Elliott, P. Studies on the enzymic reduction of amino acids. II. Purification and properties of a D-proline reductase and a proline racemase from Clostridium sticklandii. J. Biol. Chem. 228 (1957) 983-997.

[EC 5.1.1.4 created 1961]

EC 5.1.1.5

Accepted name: lysine racemase

Reaction: L-lysine = D-lysine

Systematic name: lysine racemase

Comments: The enzyme is involved in a lysine catabolic pathway.

Links to other databases: BRENDA, EXPASY, GTD, KEGG, Metacyc, CAS registry number: 9024-10-6

References:

1. Huang, H.T. and Davisson, J.W. Distribution of lysine racemase in bacteria. J. Bacteriol. 76 (1958) 495-498. [PMID: 13598707]

2. Huang, H.T. dl-Lysine production by lysine racemase. Patent US2944943, Chem. Abstr., 54 (1960), 20073.

3. Chen, I.C., Lin, W.D., Hsu, S.K., Thiruvengadam, V. and Hsu, W.H. Isolation and characterization of a novel lysine racemase from a soil metagenomic library. Appl. Environ. Microbiol. 75 (2009) 5161-5166. [PMID: 19502445]

4. Kato, S., Hemmi, H. and Yoshimura, T. Lysine racemase from a lactic acid bacterium, Oenococcus oeni: structural basis of substrate specificity. J. Biochem. 152 (2012) 505-508. [PMID: 23035128]

[EC 5.1.1.5 created 1961]

EC 5.1.1.6

Accepted name: threonine racemase

Reaction: L-threonine = D-threonine

Glossary: D-threonine = (2R,3S)-2-amino-3-hydroxybutanoic acid

Systematic name: threonine racemase

Comments: Inverts both chiral centres.

Links to other databases: BRENDA, EXPASY, KEGG, Metacyc, CAS registry number: 9024-11-7

References:

1. Amos, H. A racemase for threonine in Escherichia coli. J. Am. Chem. Soc. 76 (1954) 3858 only.

[EC 5.1.1.6 created 1961, modified 1981]

EC 5.1.1.7

Accepted name: diaminopimelate epimerase

Reaction: LL-2,6-diaminoheptanedioate = meso-diaminoheptanedioate

For diagram click here.

Systematic name: LL-2,6-diaminoheptanedioate 2-epimerase

Links to other databases: BRENDA, EXPASY, GTD, KEGG, Metacyc, PDB, CAS registry number: 9024-22-0

References:

1. Antia, M., Hoare, D.S. and Work, W. The stereoisomers of αε-diaminopimelic acid. 3. Properties and distribution of diaminopimelic acid racemase, an enzyme causing interconversion of the LL and meso isomers. Biochem. J. 65 (1957) 448-459.

[EC 5.1.1.7 created 1961]

EC 5.1.1.8

Accepted name: 4-hydroxyproline epimerase

Reaction: trans-4-hydroxy-L-proline = cis-4-hydroxy-D-proline

For reaction pathway click here.

Other name(s): hydroxyproline epimerase; hydroxyproline 2-epimerase; L-hydroxyproline epimerase

Systematic name: 4-hydroxyproline 2-epimerase

Comments: Also interconverts trans-4-hydroxy-D-proline and cis-4-hydroxy-L-proline.

Links to other databases: BRENDA, EXPASY, GTD, KEGG, Metacyc, PDB, CAS registry number: 9024-23-1

References:

1. Adams, E. and Norton, I.L. Purification and properties of inducible hydroxyproline 2-epimerase from Pseudomonas. J. Biol. Chem. 239 (1964) 1525-1535.

[EC 5.1.1.8 created 1965, modified 1983]

EC 5.1.1.9

Accepted name: arginine racemase

Reaction: L-arginine = D-arginine

Systematic name: arginine racemase

Comments: A pyridoxal-phosphate protein.

Links to other databases: BRENDA, EXPASY, KEGG, Metacyc, CAS registry number: 37290-94-1

References:

1. Yorifuji, T., Ogata, K. and Soda, K. Crystalline arginine racemase. Biochem. Biophys. Res. Commun. 34 (1969) 760-764. [PMID: 5779761]

[EC 5.1.1.9 created 1972]

EC 5.1.1.10

Accepted name: amino-acid racemase

Reaction: An L-amino acid = a D-amino acid

Other name(s): L-amino acid racemase

Systematic name: amino-acid racemase

Comments: A pyridoxal-phosphate protein.

Links to other databases: BRENDA, EXPASY, GTD, KEGG, Metacyc, PDB, CAS registry number: 9068-61-5

References:

1. Soda, K. and Osumi, T. Crystalline amino acid racemase with low substrate specificity. Biochem. Biophys. Res. Commun. 35 (1969) 363-368. [PMID: 5788493]

[EC 5.1.1.10 created 1972]

EC 5.1.1.11

Accepted name: phenylalanine racemase (ATP-hydrolysing)

Reaction: ATP + L-phenylalanine + H2O = AMP + diphosphate + D-phenylalanine

Other name(s): phenylalanine racemase; phenylalanine racemase (adenosine triphosphate-hydrolysing); gramicidin S synthetase I

Systematic name: phenylalanine racemase (ATP-hydrolysing)

Links to other databases: BRENDA, EXPASY, KEGG, Metacyc, PDB, CAS registry number: 37290-95-2

References:

1. Yamada, M. and Kurahashi, K. Further purification and properties of adenosine triphosphate-dependent phenylalanine racemase of Bacillus brevis Nagano. J. Biochem. (Tokyo) 66 (1969) 529-540. [PMID: 5354026]

[EC 5.1.1.11 created 1972]

EC 5.1.1.12

Accepted name: ornithine racemase

Reaction: L-ornithine = D-ornithine

Systematic name: ornithine racemase

Links to other databases: BRENDA, EXPASY, KEGG, Metacyc, CAS registry number: 62213-28-9

References:

1. Chen, H.P., Lin, C.F., Lee, Y.J., Tsay, S.S. and Wu, S.H. Purification and properties of ornithine racemase from Clostridium sticklandii. J. Bacteriol. 182 (2000) 2052-2054. [PMID: 10715017]

[EC 5.1.1.12 created 1972 as EC 5.4.3.1, transferred 1976 to EC 5.1.1.12]

EC 5.1.1.13

Accepted name: aspartate racemase

Reaction: L-aspartate = D-aspartate

Other name(s): D-aspartate racemase; McyF

Systematic name: aspartate racemase

Comments: Also acts, at half the rate, on L-alanine.

Links to other databases: BRENDA, EXPASY, KEGG, PDB, Metacyc, CAS registry number: 37237-56-2

References:

1. Lamont, H.C., Staudenbauer, W.L. and Strominger, J.L. Partial purification and characterization of an aspartate racemase from Streptococcus faecalis. J. Biol. Chem. 247 (1972) 5103-5106. [PMID: 4626916]

2. Yamauchi, T., Choi, S.Y., Okada, H., Yohda, M., Kumagai, H., Esaki, N. and Soda, K. Properties of aspartate racemase, a pyridoxal 5'-phosphate-independent amino acid racemase. J. Biol. Chem. 267 (1992) 18361-18364. [PMID: 1526977]

3. Liu, L., Iwata, K., Kita, A., Kawarabayasi, Y., Yohda, M. and Miki, K. Crystal structure of aspartate racemase from Pyrococcus horikoshii OT3 and its implications for molecular mechanism of PLP-independent racemization. J. Mol. Biol. 319 (2002) 479-489. [PMID: 12051922]

4. Sielaff, H., Dittmann, E., Tandeau De Marsac, N., Bouchier, C., von Dühren, H., Börner, T. and Schwecke, T. The mcyF gene of the microcystin biosynthetic gene cluster from Microcystis aeruginosa encodes an aspartate racemase. Biochem. J. 373 (2003) 909-916. [PMID: 12713441]

5. Yamashita, T., Ashiuchi, M., Ohnishi, K., Kato, S., Nagata, S. and Misono, H. Molecular identification of monomeric aspartate racemase from Bifidobacterium bifidum. Eur. J. Biochem. 271 (2004) 4798-4803. [PMID: 15606767]

[EC 5.1.1.13 created 1976]

EC 5.1.1.14

Accepted name: nocardicin A epimerase

Reaction: (1) isonocardicin C = nocardicin C
(2) isonocardicin A = nocardicin A

For diagram of reaction click here.

Other name(s): isonocardicin A epimerase; nocJ (gene name)

Systematic name: nocardicin-C epimerase

Comments: Requires pyridoxal 5'-phosphate. The enzyme, characterized from the bacterium Nocardia uniformis, is involved in the biosynthesis of the monolactam antibiotic nocardicin A. It catalyses the epimerization of the amino group at position 9' from (S)- configuration to (R)-. The enzyme can act on both isonocardicin A and isonocardicin C, but the in vivo substrate appears to be the latter [3].

Links to other databases: BRENDA, EXPASY, KEGG, MetaCyc, CAS registry number: 118246-75-6

References:

1. Wilson, B.A., Bantia, S., Salituro, G.M., Reeve, A.M. and Townsend, C.A. Cell-free biosynthesis of nocardicin A from nocardicin E and S-adenosylmethionine. J. Am. Chem. Soc. 110 (1988) 8238-8239.

2. Kelly, W.L. and Townsend, C.A. Mutational analysis and characterization of nocardicin C-9' epimerase. J. Biol. Chem. 279 (2004) 38220-38227. [PMID: 15252031]

3. Kelly, W.L. and Townsend, C.A. Mutational analysis of nocK and nocL in the nocardicin a producer Nocardia uniformis. J. Bacteriol. 187 (2005) 739-746. [PMID: 15629944]

[EC 5.1.1.14 created 1992, modified 2016]

EC 5.1.1.15

Accepted name: 2-aminohexano-6-lactam racemase

Reaction: (S)-2-aminohexano-6-lactam = (R)-2-aminohexano-6-lactam

Glossary: (S)-2-aminohexano-6-lactam = L-lysine 1,6-lactam

Other name(s): α-amino-ε-caprolactam racemase

Systematic name: 2-aminohexano-6-lactam racemase

Comments: Contains pyridoxal 5'-phosphate. Also racemises 2-aminopentano-5-lactam (α-amino-δ-valerolactam) and 2-amino-4-thiahexano-6-lactam (where S replaces CH2 of C-4). It does not catalyse the racemisation of α-amino acids but has some transaminase activity with them.

Links to other databases: BRENDA, EXPASY, KEGG, Metacyc, CAS registry number: 52652-64-9

References:

1. Ahmed, S.A., Esaki, N., Tanaka, H., Soda, K. L-α-Amino-β-thio-ε-caprolactam, a new sulfur-containing substrate for α-amino-ε-caprolactam racemase. FEBS Lett. 174 (1984) 76-79.

2. Ahmed, S.A., Esaki, N., Tanaka, H., Soda, K. Mechanism of α-amino-ε-caprolactam racemase reaction. Biochemistry 25 (1986) 385-388. [PMID: 3955003]

3. Okazaki, S., Suzuki, A., Mizushima, T., Kawano, T., Komeda, H., Asano, Y. and Yamane, T. The novel structure of a pyridoxal 5'-phosphate-dependent fold-type I racemase, α-amino-ε-caprolactam racemase from Achromobacter obae. Biochemistry 48 (2009) 941–950. [PMID: 19146406]

[EC 5.1.1.15 created 1999]

EC 5.1.1.16

Accepted name: protein-serine epimerase

Reaction: [protein]-L-serine = [protein]-D-serine

Other name(s): protein-serine racemase

Systematic name: [protein]-serine epimerase

Comments: the enzyme specifically interconverts the configuration of Ser-46 of the peptide ω-agatoxin-KT, found in the venom of the funnel web spider, Agelenopsis aperta, but not that of the other serine residue, Ser-28.

Links to other databases: BRENDA, EXPASY, KEGG, Metacyc, CAS registry number: 169592-52-3

References:

1. Shikata, Y., Watanabe, T., Teramoto, T., Inoue, A., Kawakami, Y., Nishizawa, Y., Katayama, K., Kuwada, M. Isolation and characterization of a peptide isomerase from funnel web spider venom. J. Biol. Chem. 270 (1995) 16719-16723. [PMID: 7622482]

[EC 5.1.1.16 created 1999]

EC 5.1.1.17

Accepted name: isopenicillin-N epimerase

Reaction: isopenicillin N = penicillin N

For diagram click here.

Systematic name: penicillin-N 5-amino-5-carboxypentanoyl-epimerase

Comments: This enzyme contains pyridoxal phosphate. Epimerization at C-5 of the 5-amino-5-carboxypentanoyl group to form penicillin N is required to make a substrate for EC 1.14.20.1, deactoxycephalosporin-C synthase, to produce cephalosporins. Forms part of the penicillin biosynthesis pathway (for pathway, click here).

Links to other databases: BRENDA, EXPASY, KEGG, Metacyc, CAS registry number: 88201-43-8

References:

1. Usui, S. and Yu, C.-A. Purification and properties of isopenicillin-N epimerase from Streptomyces clavuligerus. Biochim. Biophys. Acta 999 (1989) 78-85. [PMID: 2804141]

2. Laiz, L., Liras, P., Castro, J.M. and Martín, J.F. Purification and characterization of the isopenicillin-N epimerase from Nocardia lactamdurans. J. Gen. Microbiol. 136 (1990) 663-671.

3. Cantwell, C., Beckmann, R., Whiteman, P., Queener, S.W. and Abraham, E.P. Isolation of deacetoxycephalosporin-c from fermentation broths of Penicillium chrysogenum transformants - construction of a new fungal biosynthetic-pathway. Proc. R. Soc. Lond. B Biol. Sci. 248 (1992) 283-289. [PMID: 1354366]

4. Yeh, W.K., Ghag, S.K. and Queener, S.W. Enzymes for epimerization of isopenicillin N, ring expansion of penicillin N, and 3'-hydroxylation of deacetoxycephalosporin C. Function, evolution, refolding, and enzyme engineering. Ann. N.Y. Acad. Sci. 672 (1992) 396-408.

[EC 5.1.1.17 created 2002]

EC 5.1.1.18

Accepted name: serine racemase

Reaction: L-serine = D-serine

Other name(s): SRR

Systematic name: serine racemase

Comments: A pyridoxal-phosphate protein that is highly selective for L-serine as substrate. D-Serine is found in type-II astrocytes in mammalian brain, where it appears to be an endogenous ligand of the glycine site of N-methyl-D-aspartate (NMDA) receptors [1,2]. The reaction can also occur in the reverse direction but does so more showly at physiological serine concentrations [4].

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

References:

1. Wolosker, H., Blackshaw, S. and Snyder, S.H. Serine racemase: a glial enzyme synthesizing D-serine to regulate glutamate-N-methyl-D-aspartate neurotransmission. Proc. Natl. Acad. Sci. USA 96 (1999) 13409-13414. [PMID: 10557334]

2. Wolosker, H., Sheth, K.N., Takahashi, M., Mothet, J.P., Brady, R.O., Jr., Ferris, C.D. and Snyder, S.H. Purification of serine racemase: biosynthesis of the neuromodulator D-serine. Proc. Natl. Acad. Sci. USA 96 (1999) 721-725. [PMID: 9892700]

3. De Miranda, J., Santoro, A., Engelender, S. and Wolosker, H. Human serine racemase: moleular cloning, genomic organization and functional analysis. Gene 256 (2000) 183-188. [PMID: 11054547]

4. Foltyn, V.N., Bendikov, I., De Miranda, J., Panizzutti, R., Dumin, E., Shleper, M., Li, P., Toney, M.D., Kartvelishvily, E. and Wolosker, H. Serine racemase modulates intracellular D-serine levels through an α,β-elimination activity. J. Biol. Chem. 280 (2005) 1754-1763. [PMID: 15536068]

[EC 5.1.1.18 created 2007]

EC 5.1.1.19

Accepted name: O-ureido-serine racemase

Reaction: O-ureido-L-serine = O-ureido-D-serine

Glossary: O-ureido-L-serine = (2S)-2-amino-3-[(carbamoylamino)oxy]propanoate
O-ureido-D-serine = (2R)-2-amino-3-[(carbamoylamino)oxy]propanoate

Other name(s): dcsC (gene name)

Systematic name: (2S)-2-amino-3-[(carbamoylamino)oxy]propanoate 2-epimerase

Comments: The enzyme employs a two-base mechanism, with a thiolate-thiol pair in the active site. It participates in the biosynthetic pathway of D-cycloserine, an antibiotic substance produced by several Streptomyces species.

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

References:

1. Kumagai, T., Koyama, Y., Oda, K., Noda, M., Matoba, Y. and Sugiyama, M. Molecular cloning and heterologous expression of a biosynthetic gene cluster for the antitubercular agent D-cycloserine produced by Streptomyces lavendulae. Antimicrob. Agents Chemother. 54 (2010) 1132-1139. [PMID: 20086163]

2. Dietrich, D., van Belkum, M.J. and Vederas, J.C. Characterization of DcsC, a PLP-independent racemase involved in the biosynthesis of D-cycloserine. Org. Biomol. Chem. 10 (2012) 2248-2254. [PMID: 22307920]

[EC 5.1.1.19 created 2013]

EC 5.1.1.20

Accepted name: L-Ala-D/L-Glu epimerase

Reaction: L-alanyl-D-glutamate = L-alanyl-L-glutamate

Other name(s): YkfB; YcjG; AEE; AE epimerase

Systematic name: L-alanyl-D-glutamate epimerase

Comments: The enzyme, characterized from the bacteria Escherichia coli and Bacillus subtilis, is involved in the recycling of the murein peptide, of which L-Ala-D-Glu is a component. In vitro the enzyme from Escherichia coli epimerizes several L-Ala-L-X dipeptides with broader specificity than the enzyme from Bacillus subtilis.

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

References:

1. Schmidt, D.M., Hubbard, B.K. and Gerlt, J.A. Evolution of enzymatic activities in the enolase superfamily: functional assignment of unknown proteins in Bacillus subtilis and Escherichia coli as L-Ala-D/L-Glu epimerases. Biochemistry 40 (2001) 15707-15715. [PMID: 11747447]

2. Gulick, A.M., Schmidt, D.M., Gerlt, J.A. and Rayment, I. Evolution of enzymatic activities in the enolase superfamily: crystal structures of the L-Ala-D/L-Glu epimerases from Escherichia coli and Bacillus subtilis. Biochemistry 40 (2001) 15716-15724. [PMID: 11747448]

[EC 5.1.1.20 created 2015]

EC 5.1.1.21

Accepted name: isoleucine 2-epimerase

Reaction: L-isoleucine = D-allo-isoleucine

Other name(s): BCAA racemase

Systematic name: isoleucine 2-epimerase

Comments: A pyridoxal phosphate protein. The enzyme, characterized from the bacterium Lactobacillus buchneri, specifically catalyses racemization of nonpolar amino acids at the C-2 position.

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

References:

1. Mutaguchi, Y., Ohmori, T., Wakamatsu, T., Doi, K. and Ohshima, T. Identification, purification, and characterization of a novel amino acid racemase, isoleucine 2-epimerase, from Lactobacillus species. J. Bacteriol. 195 (2013) 5207-5215. [PMID: 24039265]

[EC 5.1.1.21 created 2015]


EC 5.1.2 Acting on Hydroxy Acids and Derivatives

Contents

EC 5.1.2.1 lactate racemase
EC 5.1.2.2 mandelate racemase
EC 5.1.2.3 3-hydroxybutyryl-CoA epimerase
EC 5.1.2.4 acetoin racemase
EC 5.1.2.5 tartrate epimerase
EC 5.1.2.6 isocitrate epimerase


Entries

EC 5.1.2.1

Accepted name: lactate racemase

Reaction: (S)-lactate = (R)-lactate

Other name(s): lacticoracemase; hydroxyacid racemase; lactic acid racemase

Systematic name: lactate racemase

Links to other databases: BRENDA, EXPASY, KEGG, Metacyc, Metacyc, CAS registry number: 9024-05-9

References:

1. Huennekens, F.M., Mahler, H.R. and Nordmann, J. Studies on the cyclophorase system. XVII. The occurrence and properties of an α-hydroxy acid racemase. Arch. Biochem. 30 (1951) 77-89.

2. Kitahara, K., Obayashi, A. and Fukui, S. Racemase I cell-free racemase. Enzymologia 15 (1953) 259-266.

[EC 5.1.2.1 created 1961]

EC 5.1.2.2

Accepted name: mandelate racemase

Reaction: (S)-mandelate = (R)-mandelate

Glossary: mandelate = 2-hydroxy-2-phenylacetate

Systematic name: mandelate racemase

Links to other databases: BRENDA, EXPASY, KEGG, Metacyc, PDB, UM-BBD, CAS registry number: 9024-04-8

References:

1. Gunsalus, C.F., Stanier, R.Y. and Gunsalus, I.C. The enzymatic conversion of mandelic acid to benzoic acid. III. Fractionation and properties of the soluble enzymes. J. Bacteriol. 66 (1953) 548-553.

[EC 5.1.2.2 created 1961]

EC 5.1.2.3

Accepted name: 3-hydroxybutyryl-CoA epimerase

Reaction: (S)-3-hydroxybutanoyl-CoA = (R)-3-hydroxybutanoyl-CoA

Other name(s): 3-hydroxybutyryl coenzyme A epimerase; 3-hydroxyacyl-CoA epimerase

Systematic name: 3-hydroxybutanoyl-CoA 3-epimerase

Links to other databases: BRENDA, EXPASY, KEGG, Metacyc, PDB, CAS registry number: 9024-21-9

References:

1. Stern, J.R., del Campillo, A. and Lehninger, A.L. Enzymatic racemization of β-hydroxybutyryl-S-CoA and the stereospecificity of enzymes of the fatty acid cycle. J. Am. Chem. Soc. 77 (1955) 1073-1074.

2. Wakil, S.J. D(–)β-Hydroxybutyryl CoA dehydrogenase. Biochim. Biophys. Acta 18 (1955) 314-315.

[EC 5.1.2.3 created 1961]

EC 5.1.2.4

Accepted name: acetoin racemase

Reaction: (S)-acetoin = (R)-acetoin

Other name(s): acetylmethylcarbinol racemase

Systematic name: acetoin racemase

Links to other databases: BRENDA, EXPASY, KEGG, Metacyc, CAS registry number: 37318-32-4

References:

1. Taylor, M.B. and Juni, E. Stereoisomeric specificities of 2,3-butanediol dehydrogenases. Biochim. Biophys. Acta 39 (1960) 448-457.

[EC 5.1.2.4 created 1972]

EC 5.1.2.5

Accepted name: tartrate epimerase

Reaction: (R,R)-tartrate = meso-tartrate

Other name(s): tartaric racemase

Systematic name: tartrate epimerase

Links to other databases: BRENDA, EXPASY, KEGG, Metacyc, CAS registry number: 37318-33-5

References:

1. Ranjan, S., Patnaik, K.K. and Laloraya, M.M. Enzymic conversion of meso-tartrate to dextro-tartrate in tamarind. Naturwissenschaften 48 (1961) 406 only.

[EC 5.1.2.5 created 1972]

EC 5.1.2.6

Accepted name: isocitrate epimerase

Reaction: (1R,2S)-1-hydroxypropane-1,2,3-tricarboxylate = (1S,2S)-1-hydroxypropane-1,2,3-tricarboxylate

For diagram click here.

Glossary: isocitrate = (1R,2S)-1-hydroxypropane-1,2,3-tricarboxylate = threo-Ds-isocitrate
allocitrate = (1S,2S)-1-hydroxypropane-1,2,3-tricarboxylate = D-erythro-isocitrate

Systematic name: (1R,2S)-1-hydroxypropane-1,2,3-tricarboxylate 1-epimerase

Comments: (1R,2S)-1-hydroxypropane-1,2,3-tricarboxylate is the commonly occurring isomer of isocitrate.

Links to other databases: BRENDA, EXPASY, KEGG, Metacyc, CAS registry number: 81210-68-6

References:

1. Hoshiko, S., Kunimoto, Y., Arima, K. and Beppu, T. Mechanism of L-alloisocitric acid fermentation: isocitrate epimerase activity in the cell-free-extract of Penicillium purpurogenum. Agric. Biol. Chem. 46 (1982) 143-151.

[EC 5.1.2.6 created 1984]


Continued with EC 5.1.3.1 to EC 5.1.99.3
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