Enzyme Nomenclature

Continued from EC 4.2.99

EC 4.3

Carbon-Nitrogen Lyases

This subclass contains the enzymes that release ammonia or one of its derivatives, with the formation of a double bond or ring. Some catalyse the actual elimination of the ammonia, amine or amide, e.g.

>CH-CH(-NH-R)- → >C=CH- + NH2-R

Others, however, catalyse elimination of another component, e.g. water, which is followed by spontaneous reactions that lead to breakage of the C-N bond, e.g.

as in EC 4.3.1.17 (L-serine ammonia-lyase), so that the overall reaction is

>C(-OH)-CH(-NH2)- → >CH2-CO- + NH3

Sections

EC 4.3.1 Ammonia-Lyases
EC 4.3.2 Lyases Acting on Amides, Amidines, etc.
EC 4.3.3 Amine-Lyases
EC 4.3.99 Other Carbon-Nitrogen Lyases


EC 4.3.1 Ammonia-Lyases

Contents

EC 4.3.1.1 aspartate ammonia-lyase
EC 4.3.1.2 methylaspartate ammonia-lyase
EC 4.3.1.3 histidine ammonia-lyase
EC 4.3.1.4 formiminotetrahydrofolate cyclodeaminase
EC 4.3.1.5 transferred, now divided into EC 4.3.1.23, EC 4.3.1.24 and EC 4.3.1.25
EC 4.3.1.6 β-alanyl-CoA ammonia-lyase
EC 4.3.1.7 ethanolamine ammonia-lyase
EC 4.3.1.8 now EC 2.5.1.61
EC 4.3.1.9 glucosaminate ammonia-lyase
EC 4.3.1.10 serine-sulfate ammonia-lyase
EC 4.3.1.11 deleted
EC 4.3.1.12 now EC 1.4.1.22
EC 4.3.1.13 carbamoyl-serine ammonia-lyase
EC 4.3.1.14 3-aminobutyryl-CoA ammonia-lyase
EC 4.3.1.15 diaminopropionate ammonia-lyase
EC 4.3.1.16 threo-3-hydroxy-L-aspartate ammonia-lyase
EC 4.3.1.17 L-serine ammonia-lyase
EC 4.3.1.18 D-serine ammonia-lyase
EC 4.3.1.19 threonine ammonia-lyase
EC 4.3.1.20 erythro-3-hydroxy-L-aspartate ammonia-lyase
EC 4.3.1.21 identical to EC 4.3.1.9
EC 4.3.1.22 3,4-dihydroxyphenylalanine reductive deaminase
EC 4.3.1.23 tyrosine ammonia-lyase
EC 4.3.1.24 phenylalanine ammonia-lyase
EC 4.3.1.25 phenylalanine/tyrosine ammonia-lyase
EC 4.3.1.26 transferred now EC 1.21.3.9
EC 4.3.1.27 threo-3-hydroxy-D-aspartate ammonia-lyase
EC 4.3.1.28 L-lysine cyclodeaminase
EC 4.3.1.29 D-glucosaminate-6-phosphate ammonia lyase
EC 4.3.1.30 dTDP-4-amino-4,6-dideoxy-D-glucose ammonia-lyase
EC 4.3.1.31 L-tryptophan ammonia lyase


Entries

EC 4.3.1.1

Accepted name: aspartate ammonia-lyase

Reaction: L-aspartate = fumarate + NH3

Other name(s): aspartase; fumaric aminase; L-aspartase; L-aspartate ammonia-lyase

Systematic name: L-aspartate ammonia-lyase (fumarate-forming)

Links to other databases: BRENDA, EXPASY, GTD, KEGG, Metacyc, PDB, CAS registry number: 9027-30-9

References:

1. Ellfolk, N. Studies on aspartase. 1. Quantitative separation of aspartase from bacterial cells, and its partial purification. Acta Chem. Scand. 7 (1953) 824-830.

[EC 4.3.1.1 created 1961]

EC 4.3.1.2

Accepted name: methylaspartate ammonia-lyase

Reaction: L-threo-3-methylaspartate = mesaconate + NH3

Other name(s): β-methylaspartase; 3-methylaspartase; L-threo-3-methylaspartate ammonia-lyase

Systematic name: L-threo-3-methylaspartate ammonia-lyase (mesaconate-forming)

Comments: A cobalamin protein.

Links to other databases: BRENDA, EXPASY, GTD, KEGG, Metacyc, PDB, CAS registry number: 9033-26-5

References:

1. Barker, H.A., Smyth, R.O., Wawszkiewicz, E.J., Lee, M.N. and Wilson, R.M. Enzymic preparation and characterization of an α-L-β-methylaspartic acid. Arch. Biochem. Biophys. 78 (1958) 468-476.

2. Bright, H.J. and Ingraham, L.L. The preparation of crystalline β-methylaspartase. Biochim. Biophys. Acta 44 (1960) 586-588. [PMID: 13618029]

[EC 4.3.1.2 created 1961]

EC 4.3.1.3

Accepted name: histidine ammonia-lyase

Reaction: L-histidine = urocanate + NH3

For diagram of reaction click here

Glossary: urocanate = (E)-3-(imidazol-4-yl)propenoate

Other name(s): histidase; histidinase; histidine α-deaminase; L-histidine ammonia-lyase

Systematic name: L-histidine ammonia-lyase (urocanate-forming)

Comments: This enzyme is a member of the aromatic amino acid lyase family, other members of which are EC 4.3.1.23 (tyrosine ammonia-lyase), EC 4.3.1.24 (phenylalanine ammonia-lyase) and EC 4.3.1.25 (phenylalanine/tyrosine ammonia-lyase). The enzyme contains the cofactor 3,5-dihydro-5-methylidene-4H-imidazol-4-one (MIO), which is common to this family [4]. This unique cofactor is formed autocatalytically by cyclization and dehydration of the three amino-acid residues alanine, serine and glycine [5]. This enzyme catalyses the first step in the degradation of histidine and the product, urocanic acid, is further metabolized to glutamate [2,3].

Links to other databases: BRENDA, EXPASY, GTD, KEGG, Metacyc, PDB, CAS registry number: 9013-75-6

References:

1. Mehler, A.H. and Tabor, H. Deamination of histidine to form urocanic acid in liver. J. Biol. Chem. 201 (1953) 775-784. [PMID: 13061415]

2. Watts, K.T., Mijts, B.N., Lee, P.C., Manning, A.J. and Schmidt-Dannert, C. Discovery of a substrate selectivity switch in tyrosine ammonia-lyase, a member of the aromatic amino acid lyase family. Chem. Biol. 13 (2006) 1317-1326. [PMID: 17185227]

3. Poppe, L. and Rétey, J. Friedel-Crafts-type mechanism for the enzymatic elimination of ammonia from histidine and phenylalanine. Angew. Chem. Int. Ed. Engl. 44 (2005) 3668-3688. [PMID: 15906398]

4. Louie, G.V., Bowman, M.E., Moffitt, M.C., Baiga, T.J., Moore, B.S. and Noel, J.P. Structural determinants and modulation of substrate specificity in phenylalanine-tyrosine ammonia-lyases. Chem. Biol. 13 (2006) 1327-1338. [PMID: 17185228]

5. Schwede, T.F., Rétey, J. and Schulz, G.E. Crystal structure of histidine ammonia-lyase revealing a novel polypeptide modification as the catalytic electrophile. Biochemistry 38 (1999) 5355-5361. [PMID: 10220322]

[EC 4.3.1.3 created 1961, modified 2008]

EC 4.3.1.4

Accepted name: formimidoyltetrahydrofolate cyclodeaminase

Reaction: 5-formimidoyltetrahydrofolate = 5,10-methenyltetrahydrofolate + NH3

For diagram of reaction click here (another example).

Other name(s): formiminotetrahydrofolate cyclodeaminase; 5-formimidoyltetrahydrofolate ammonia-lyase (cyclizing)

Systematic name: 5-formimidoyltetrahydrofolate ammonia-lyase (cyclizing; 5,10-methenyltetrahydrofolate-forming)

Comments: In eukaroytes, occurs as a bifunctional enzyme that also has glutamate formimidoyltransferase (EC 2.1.2.5) activity.

Links to other databases: BRENDA, EXPASY, KEGG, Metacyc, PDB, CAS registry number: 9032-05-7

References:

1. Rabinowitz, J.C. and Pricer, W.E. Formimino-tetrahydrofolic acid and methenyltetrahydrofolic acid as intermediates in the formation of N10-formyltetrahydrofolic acid. J. Am. Chem. Soc. 78 (1956) 5702-5704.

[EC 4.3.1.4 created 1961, modified 2000]

[EC 4.3.1.5 Transferred entry: phenylalanine ammonia-lyase. Now divided into EC 4.3.1.23 (tyrosine ammonia-lyase), EC 4.3.1.24 (phenylalanine ammonia-lyase) and EC 4.3.1.25 (phenylalanine/tyrosine ammonia-lyase). (EC 4.3.1.5 created 1965, deleted 2008)]

EC 4.3.1.6

Accepted name: β-alanyl-CoA ammonia-lyase

Reaction: β-alanyl-CoA = acryloyl-CoA + NH3

Other name(s): β-alanyl coenzyme A ammonia-lyase; β-alanyl-CoA ammonia-lyase

Systematic name: β-alanyl-CoA ammonia-lyase (acryloyl-CoA-forming)

Comments: The reaction has only been demonstrated in the direction of addition of ammonia.

Links to other databases: BRENDA, EXPASY, GTD, KEGG, Metacyc, CAS registry number: 9024-29-7

References:

1. Stadtman, E.R. The enzymic synthesis of β-alanyl coenzyme A. J. Am. Chem. Soc. 77 (1955) 5765-5766.

[EC 4.3.1.6 created 1965]

EC 4.3.1.7

Accepted name: ethanolamine ammonia-lyase

Reaction: ethanolamine = acetaldehyde + NH3

Other name(s): ethanolamine deaminase; ethanolamine ammonia-lyase

Systematic name: ethanolamine ammonia-lyase (acetaldehyde-forming)

Comments: A cobalamin protein.

Links to other databases: BRENDA, EXPASY, KEGG, Metacyc, PDB, CAS registry number: 9054-69-7

References:

1. Bradbeer, C. The clostridial fermentations of choline and ethanolamine. 1. Preparation and properties of cell-free extracts. J. Biol. Chem. 240 (1965) 4669-4474. [PMID: 5846987]

2. Bradbeer, C. The clostridial fermentations of choline and ethanolamine. II. Requirement for a cobamide coenzyme by an ethanolamine deaminase. J. Biol. Chem. 240 (1965) 4675-4681. [PMID: 5846988]

3. Kaplan, B.H. and Stadtman, E.R. Ethanolamine deaminase, a cobamide coenzyme-dependent enzyme. I. Purification, assay, and properties of the enzyme. J. Biol. Chem. 243 (1968) 1787-1793. [PMID: 4297225]

[EC 4.3.1.7 created 1972]

[EC 4.3.1.8 Transferred entry: now EC 2.5.1.61 hydroxymethylbilane synthase. (EC 4.3.1.8 created 1972, deleted 2003)]

EC 4.3.1.9

Accepted name: glucosaminate ammonia-lyase

Reaction: 2-amino-2-deoxy-D-gluconate = 2-dehydro-3-deoxy-D-gluconate + NH3 (overall reaction)
(1a) 2-amino-2-deoxy-D-gluconate = (2Z,4S,5R)-2-amino-4,5,6-trihydroxyhex-2-enoate + H2O
(1b) (2Z,4S,5R)-2-amino-4,5,6-trihydroxyhex-2-enoate = (4S,5R)-4,5,6-trihydroxy-2-iminohexanoate (spontaneous)
(1c) (4S,5R)-4,5,6-trihydroxy-2-iminohexanoate + H2O = 2-dehydro-3-deoxy-D-gluconate + NH3 (spontaneous)

Glossary: 2-amino-2-deoxy-D-gluconate = glucosaminate

Other name(s): glucosaminic dehydrase; D-glucosaminate dehydratase; D-glucosaminic acid dehydrase; aminodeoxygluconate dehydratase; 2-amino-2-deoxy-D-gluconate hydro-lyase (deaminating); aminodeoxygluconate ammonia-lyase; 2-amino-2-deoxy-D-gluconate ammonia-lyase; D-glucosaminate ammonia-lyase

Systematic name: D-glucosaminate ammonia-lyase (isomerizing; 2-dehydro-3-deoxy-D-gluconate-forming)

Comments: Contains pyridoxal phosphate. The enzyme releases an unstable enamine product that tautomerizes to an imine form, which undergoes spontaneous hydrolytic deamination to form the final product.

Links to other databases: BRENDA, EXPASY, KEGG, Metacyc, CAS registry number: 37290-91-8

References:

1. Imanaga, Y. Metabolism of D-glucosamine. III. Enzymic degradation of D-glucosaminic acid. J. Biochem. (Tokyo) 45 (1958) 647-650.

2. Merrick, J.M. and Roseman, S. D-Glucosaminic acid dehydrase. Methods Enzymol. 9 (1966) 657-660.

3. Iwamoto, R., Imanaga, Y. and Soda, K. D-Glucosaminate dehydratase from Agrobacterium radiobacter. Physicochemical and enzymological properties. J. Biochem. (Tokyo) 91 (1982) 283-289. [PMID: 7068563]

4. Iwamoto, R., Taniki, H., Koishi, J. and Nakura, S. D-Glucosaminate aldolase activity of D-glucosaminate dehydratase from Pseudomonas fluorescens and its requirement for Mn2+ ion. Biosci. Biotechnol. Biochem. 59 (1995) 408-411. [PMID: 7766176]

[EC 4.3.1.9 created 1972, (EC 4.3.1.21 created 1965 as EC 4.2.1.26, transferred 2002 to EC 4.3.1.21, incorporated 2004) modified 2004]

EC 4.3.1.10

Accepted name: serine-sulfate ammonia-lyase

Reaction: L-serine O-sulfate + H2O = pyruvate + NH3 + sulfate

Other name(s): (L-SOS)lyase

Systematic name: L-serine-O-sulfate ammonia-lyase (pyruvate-forming)

Links to other databases: BRENDA, EXPASY, KEGG, Metacyc, CAS registry number: 9054-70-0

References:

1. Thomas, J.H. and Tudball, N. Studies on the enzymic degradation of L-serine O-sulphate by a rat liver preparation. Biochem. J. 105 (1967) 467-472. [PMID: 5583990]

[EC 4.3.1.10 created 1972]

[EC 4.3.1.11 Deleted entry: dihydroxyphenylalanine ammonia-lyase. The entry had been drafted on the basis of a single abstract that did not provide experimental evidence of the enzyme-catalysed reaction. (EC 4.3.1.11 created 1972, deleted 2007)]

EC 4.3.1.12

Accepted name: ornithine cyclodeaminase

Reaction: L-ornithine = L-proline + NH3

For diagram click here.

Other name(s): ornithine cyclase; ornithine cyclase (deaminating); L-ornithine ammonia-lyase (cyclizing)

Systematic name: L-ornithine ammonia-lyase (cyclizing; L-proline-forming)

Comments: Requires NAD+. The enzyme is a member of the μ-crystallin protein family [4]. The reaction is stimulated by the presence of ADP or ATP and is inhibited by O2 [2].

Links to other databases: BRENDA, EXPASY, KEGG, Metacyc, CAS registry number: 9054-76-6

References:

1. Costilow, R.N. and Laycock, L. Ornithine cyclase (deaminating). Purification of a protein that converts ornithine to proline and definition of the optimal assay conditions. J. Biol. Chem. 246 (1971) 6655-6660. [PMID: 4399881]

2. Muth, W.L. and Costilow, R.N. Ornithine cyclase (deaminating). II. Properties of the homogeneous enzyme. J. Biol. Chem. 249 (1974) 7457-7462. [PMID: 4373469]

3. 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]

4. Goodman, J.L., Wang, S., Alam, S., Ruzicka, F.J., Frey, P.A. and Wedekind, J.E. Ornithine cyclodeaminase: structure, mechanism of action, and implications for the μ-crystallin family. Biochemistry 43 (2004) 13883-13891. [PMID: 15518536]

5. Alam, S., Wang, S.C., Ruzicka, F.J., Frey, P.A. and Wedekind, J.E. Crystallization and X-ray diffraction analysis of ornithine cyclodeaminase from Pseudomonas putida. Acta Crystallogr. D Biol. Crystallogr. 60 (2004) 941-944. [PMID: 15103146]

[EC 4.3.1.12 created 1976]

EC 4.3.1.13

Accepted name: carbamoyl-serine ammonia-lyase

Reaction: O-carbamoyl-L-serine + H2O = pyruvate + 2 NH3 + CO2 (overall reaction)
(1a) O-carbamoyl-L-serine = CO2 + NH3 + 2-aminoprop-2-enoate
(1b) 2-aminoprop-2-enoate = 2-iminopropanoate (spontaneous)
(1c) 2-iminopropanoate + H2O = pyruvate + NH3 (spontaneous)

Other name(s): O-carbamoyl-L-serine deaminase; carbamoylserine deaminase; O-carbamoyl-L-serine ammonia-lyase (pyruvate-forming)

Systematic name: O-carbamoyl-L-serine ammonia-lyase (decarboxylating; pyruvate-forming)

Comments: A pyridoxal-phosphate protein. The enzyme cleaves a carbon-oxygen bond, releasing CO2, ammonia, and an unstable enamine product that tautomerizes to an imine form, which undergoes a hydrolytic deamination to form pyruvate and a second ammonia molecule. The latter reaction, which can occur spontaneously, can also be catalysed by EC 3.5.99.10, 2-iminobutanoate/2-iminopropanoate deaminase.

Links to other databases: BRENDA, EXPASY, KEGG, Metacyc, CAS registry number: 52227-64-2

References:

1. Cooper, A.J.L. and Meister, A. Enzymatic conversion of O-carbamyl-L-serine to pyruvate and ammonia. Biochem. Biophys. Res. Commun. 55 (1973) 780-787. [PMID: 4399881]

[EC 4.3.1.13 created 1976]

EC 4.3.1.14

Accepted name: 3-aminobutyryl-CoA ammonia-lyase

Reaction: L-3-aminobutyryl-CoA = crotonoyl-CoA + NH3

For diagram of reaction click here.

Other name(s): L-3-aminobutyryl-CoA deaminase; L-3-aminobutyryl-CoA ammonia-lyase

Systematic name: L-3-aminobutyryl-CoA ammonia-lyase (crotonoyl-CoA-forming)

Comments: Hydroxylamine can replace ammonia as a substrate. Crotonoyl-pantetheine can replace crotonoyl-CoA but it is a poorer substrate.

Links to other databases: BRENDA, EXPASY, KEGG, Metacyc, CAS registry number: 55467-41-9

References:

1. Jeng, I.-M., Barker, H.A. Purification and properties of L-3-aminobutyryl coenzyme A deaminase from a lysine-fermenting Clostridium. J. Biol. Chem. 249 (1974) 6578-6584. [PMID: 4420467]

2. Barker, H.A., Kahn, J.M., Chew, S. Enzymes involved in 3,5-diaminohexanoate degradation by Brevibacterium sp. J. Bacteriol. 143 (1980) 1165-1170. [PMID: 7410315]

[EC 4.3.1.14 created 1999]

EC 4.3.1.15

Accepted name: diaminopropionate ammonia-lyase

Reaction: 2,3-diaminopropanoate + H2O = pyruvate + 2 NH3

Other name(s): diaminopropionatase; α,β-diaminopropionate ammonia-lyase; 2,3-diaminopropionate ammonia-lyase; 2,3-diaminopropanoate ammonia-lyase

Systematic name: 2,3-diaminopropanoate ammonia-lyase (adding water; pyruvate-forming)

Comments: A pyridoxal phosphate enzyme. Active towards both D- and L-diaminopropanoate. D- and L-serine are poor substrates.

Links to other databases: BRENDA, EXPASY, KEGG, Metacyc, PDB, CAS registry number: 51901-19-0

References:

1. Nagasawa, T., Tanizawa, K., Satoda, T., Yamada, H. Diaminopropionate ammonia-lyase from Salmonella typhimurium. Purification and characterization of the crystalline enzyme, and sequence determination of the pyridoxal 5'-phosphate binding peptide. J. Biol. Chem. 263 (1988) 958-964. [PMID: 3275662]

[EC 4.3.1.15 created 1999]

EC 4.3.1.16

Accepted name: threo-3-hydroxy-L-aspartate ammonia-lyase

Reaction: threo-3-hydroxy-L-aspartate = oxaloacetate + NH3

Other name(s): L-threo-3-hydroxyaspartate dehydratase; threo-3-hydroxyaspartate ammonia-lyase

Systematic name: threo-3-hydroxy-L-aspartate ammonia-lyase (oxaloacetate-forming)

Comments: A pyridoxal-phosphate protein. The enzyme, purified from the bacterium Pseudomonas sp. T62, is highly specific, and does not accept any other stereoisomer of 3-hydroxyaspartate. Different from EC 4.3.1.20, erythro-3-hydroxy-L-aspartate ammonia-lyase and EC 4.3.1.27, threo-3-hydroxy-D-aspartate ammonia-lyase. Requires a divalent cation such as Mn2+, Mg2+, or Ca2+.

Links to other databases: BRENDA, EXPASY, KEGG, Metacyc, CAS registry number: 248270-70-4

References:

1. Wada, M., Matsumoto, T., Nakamori, S., Sakamoto, M., Kataoka, M., Liu, J.-Q., Itoh, N., Yamada, H. and Shimizu, S. Purification and characterization of a novel enzyme, L-threo-3-hydroxyaspartate dehydratase, from Pseudomonas sp. T62. FEMS Microbiol. Lett. 179 (1999) 147-151. [PMID: 10481099]

[EC 4.3.1.16 created 2001, modified 2011]

EC 4.3.1.17

Accepted name: L-serine ammonia-lyase

Reaction: L-serine = pyruvate + NH3 (overall reaction)
(1a) L-serine = 2-aminoprop-2-enoate + H2O
(1b) 2-aminoprop-2-enoate = 2-iminopropanoate (spontaneous)
(1c) 2-iminopropanoate + H2O = pyruvate + NH3 (spontaneous)

Other name(s): serine deaminase; L-hydroxyaminoacid dehydratase; L-serine deaminase; L-serine dehydratase; L-serine hydro-lyase (deaminating)

Systematic name: L-serine ammonia-lyase (pyruvate-forming)

Comments: Most enzymes that catalyse this reaction are pyridoxal-phosphate-dependent, although some enzymes contain an iron-sulfur cluster instead [6]. The reaction catalysed by both types of enzymes involves the initial elimination of water to form an enamine intermediate (hence the enzyme’s original classification as EC 4.2.1.13, L-serine dehydratase), followed by tautomerization to an imine form and hydrolysis of the C-N bond. The latter reaction, which can occur spontaneously, is also be catalysed by EC 3.5.99.10, 2-iminobutanoate/2-iminopropanoate deaminase. This reaction is also carried out by EC 4.3.1.19, threonine ammonia-lyase, from a number of sources.

Links to other databases: BRENDA, EXPASY, KEGG, MetaCyc, PDB, CAS registry number: 9014-27-1

References:

1. Ramos, F. and Wiame, J.-M. Occurrence of a catabolic L-serine (L-threonine) deaminase in Saccharomyces cerevisiae. Eur. J. Biochem. 123 (1982) 571-576. [PMID: 7042346]

2. Simon, D., Hoshino, J. and Kröger, H. L-Serine dehydratase from rat liver. Purification and some properties. Biochim. Biophys. Acta 321 (1973) 361-368. [PMID: 4750769]

3. Suda, M. and Nakagawa, H. L-Serine dehydratase (rat liver). Methods Enzymol. 17B (1971) 346-351.

4. Sagers, R.D. and Carter, J. E. L-Serine dehydratase (Clostridium acidiurica). Methods Enzymol. 17B (1971) 351-356.

5. Robinson, W.G. and Labow, R. L-Serine dehydratase (Escherichia coli). Methods Enzymol. 17B (1971) 356-360.

6. Grabowski, R., Hofmeister, A.E. and Buckel, W. Bacterial L-serine dehydratases: a new family of enzymes containing iron-sulfur clusters. Trends Biochem. Sci. 18 (1993) 297-300. [PMID: 8236444]

7. Yamada, T., Komoto, J., Takata, Y., Ogawa, H., Pitot, H.C. and Takusagawa, F. Crystal structure of serine dehydratase from rat liver. Biochemistry 42 (2003) 12854-12865. [PMID: 14596599]

[EC 4.3.1.17 created 1961 as EC 4.2.1.13, transferred 2001 to EC 4.3.1.17, modified 2014]

EC 4.3.1.18

Accepted name: D-serine ammonia-lyase

Reaction: D-serine = pyruvate + NH3 (overall reaction)
(1a) D-serine = 2-aminoprop-2-enoate + H2O
(1b) 2-aminoprop-2-enoate = 2-iminopropanoate (spontaneous)
(1c) 2-iminopropanoate + H2O = pyruvate + NH3 (spontaneous)

Other name(s): D-hydroxyaminoacid dehydratase; D-serine dehydrase; D-hydroxy amino acid dehydratase; D-serine hydrolase; D-serine dehydratase (deaminating); D-serine deaminase; D-serine hydro-lyase (deaminating)

Systematic name: D-serine ammonia-lyase (pyruvate-forming)

Comments: A pyridoxal-phosphate protein. The enzyme cleaves a carbon-oxygen bond, releasing a water molecule (hence the enzyme’s original classification as EC 4.2.1.14, D-serine dehydratase) and an unstable enamine product that tautomerizes to an imine form, which undergoes a hydrolytic deamination to form pyruvate and ammonia. The latter reaction, which can occur spontaneously, can also be catalysed by EC 3.5.99.10, 2-iminobutanoate/2-iminopropanoate deaminase. Also acts, slowly, on D-threonine.

Links to other databases: BRENDA, EXPASY, KEGG, Metacyc, PDB, CAS registry number: 9015-88-7

References:

1. Dupourque, D., Newton, W.A. and Snell, E.E. Purification and properties of D-serine dehydrase from Escherichia coli. J. Biol. Chem. 241 (1966) 1233-1238. [PMID: 5327100]

2. Metzler, D.E. and Snell, E.E. Deamination of serine. II. D-Serine dehydrase, a vitamin B6 enzyme from Escherichia coli. J. Biol. Chem. 198 (1952) 363-373. [PMID: 12999751]

[EC 4.3.1.18 created 1961 as EC 4.2.1.14, transferred 2001 to EC 4.3.1.18]

EC 4.3.1.19

Accepted name: threonine ammonia-lyase

Reaction: L-threonine = 2-oxobutanoate + NH3 (overall reaction)
(1a) L-threonine = 2-aminobut-2-enoate + H2O
(1b) 2-aminobut-2-enoate = 2-iminobutanoate (spontaneous)
(1c) 2-iminobutanoate + H2O = 2-oxobutanoate + NH3 (spontaneous)

For diagram of reaction click here.

Other name(s): threonine deaminase; L-serine dehydratase; serine deaminase; L-threonine dehydratase; threonine dehydrase; L-threonine deaminase; threonine dehydratase; L-threonine hydro-lyase (deaminating); L-threonine ammonia-lyase

Systematic name: L-threonine ammonia-lyase (2-oxobutanoate-forming)

Comments: Most enzymes that catalyse this reaction are pyridoxal-phosphate-dependent, although some enzymes contain an iron-sulfur cluster instead. The reaction catalysed by both types of enzymes involves the initial elimination of water to form an enamine intermediate (hence the enzyme's original classification as EC 4.2.1.16, threonine dehydratase), followed by tautomerization to an imine form and hydrolysis of the C-N bond [3,5]. The latter reaction, which can occur spontaneously, is also be catalysed by EC 3.5.99.10, 2-iminobutanoate/2-iminopropanoate deaminase [5]. The enzymes from a number of sources also act on L-serine, cf. EC 4.3.1.17, L-serine ammonia-lyase.

Links to other databases: BRENDA, EXPASY, KEGG, MetaCyc, PDB, UM-BBD, CAS registry number: 774231-81-1

References:

1. Cohn, M.S. and Phillips, A.T. Purification and characterization of a B6-independent threonine dehydratase from Pseudomonas putida. Biochemistry 13 (1974) 1208-1214. [PMID: 4814721]

2. Nishimura, J.S. and Greenberg, D.M. Purification and properties of L-threonine dehydrase of sheep liver. J. Biol. Chem. 236 (1961) 2684-2691. [PMID: 14479973]

3. Phillips, A.T. and Wood, W.A. The mechanism of action of 5'-adenylic acid-activated threonine dehydrase. J. Biol. Chem. 240 (1965) 4703-4709. [PMID: 5321308]

4. Shizuta, Y., Nakazawa, A., Tokushige, M. and Hayaishi, O. Studies on the interaction between regulatory enzymes and effectors. 3. Crystallization and characterization of adenosine 5'-monophosphate-dependent threonine deaminase from Escherichia coli. J. Biol. Chem. 244 (1969) 1883-1889. [PMID: 4889010]

5. Lambrecht, J.A., Flynn, J.M. and Downs, D.M. Conserved YjgF protein family deaminates reactive enamine/imine intermediates of pyridoxal 5'-phosphate (PLP)-dependent enzyme reactions. J. Biol. Chem. 287 (2012) 3454-3461. [PMID: 22094463]

[EC 4.3.1.19 created 1961 as EC 4.2.1.16, transferred 2001 to EC 4.3.1.19, modified 2014]

EC 4.3.1.20

Accepted name: erythro-3-hydroxy-L-aspartate ammonia-lyase

Reaction: erythro-3-hydroxy-L-aspartate = oxaloacetate + NH3

Other name(s): erythro-β-hydroxyaspartate dehydratase; erythro-3-hydroxyaspartate dehydratase; erythro-3-hydroxy-Ls-aspartate hydro-lyase (deaminating); erythro-3-hydroxy-Ls-aspartate ammonia-lyase

Systematic name: erythro-3-hydroxy-L-aspartate ammonia-lyase (oxaloacetate-forming)

Comments: A pyridoxal-phosphate protein. The enzyme, which was characterized from the bacterium Paracoccus denitrificans NCIMB 8944, is highly specific for the L-isomer of erythro-3-hydroxyaspartate. Different from EC 4.3.1.16, threo-3-hydroxy-L-aspartate ammonia-lyase and EC 4.3.1.27, threo-3-hydroxy-D-aspartate ammonia-lyase. Requires a divalent cation such as Mn2+, Mg2+, and Ca2+.

Links to other databases: BRENDA, EXPASY, KEGG, Metacyc, CAS registry number: 37290-74-7

References:

1. Gibbs, R.G. and Morris, J.G. Purification and properties of erythro-β-hydroxyaspartate dehydratase from Micrococcus denitrificans. Biochem. J. 97 (1965) 547-554. [PMID: 16749162]

[EC 4.3.1.20 created 1972 as EC 4.2.1.38, transferred 2001 to EC 4.3.1.20, modified 2011]

[EC 4.3.1.21 Deleted entry: aminodeoxygluconate ammonia-lyase. Enzyme is identical to EC 4.3.1.9, glucosaminate ammonia-lyase (EC 4.3.1.21 created 1965 as EC 4.2.1.26, transferred 2002 to EC 4.3.1.21, deleted 2004)]

EC 4.3.1.22

Accepted name: 3,4-dihydroxyphenylalanine reductive deaminase

Reaction: L-dopa + NADH = 3,4-dihydroxyphenylpropanoate + NAD+ + NH3

Glossary: L-dopa = 3,4-dihydroxy-L-phenylalanine

Other name(s): reductive deaminase; DOPA-reductive deaminase; DOPARDA

Systematic name: 3,4-dihydroxy-L-phenylalanine ammonia-lyase (3,4-dihydroxyphenylpropanoate-forming)

Comments: Forms part of the L-phenylalanine-catabolism pathway in the anoxygenic phototrophic bacterium Rhodobacter sphaeroides OU5. NADPH is oxidized more slowly than NADH.

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

References:

1. Ranjith, N.K., Sasikala, Ch. and Ramana, Ch.V. Catabolism of L-phenylalanine and L-tyrosine by Rhodobacter sphaeroides OU5 occurs through 3,4-dihydroxyphenylalanine. Res. Microbiol. 158 (2007) 506-511. [PMID: 17616348]

[EC 4.3.1.22 created 2007]

EC 4.3.1.23

Accepted name: tyrosine ammonia-lyase

Reaction: L-tyrosine = trans-p-hydroxycinnamate + NH3

Other name(s): TAL; tyrase; L-tyrosine ammonia-lyase

Systematic name: L-tyrosine ammonia-lyase (trans-p-hydroxycinnamate-forming)

Comments: This enzyme is a member of the aromatic amino acid lyase family, other members of which are EC 4.3.1.3 (histidine ammonia-lyase), EC 4.3.1.24 (phenylalanine ammonia-lyase) and EC 4.3.1.25 (phenylalanine/tyrosine ammonia-lyase). The enzyme contains the cofactor 3,5-dihydro-5-methylidene-4H-imidazol-4-one (MIO), which is common to this family [1]. This unique cofactor is formed autocatalytically by cyclization and dehydration of the three amino-acid residues alanine, serine and glycine [3]. The enzyme is far more active with tyrosine than with phenylalanine as substrate, but the substrate specificity can be switched by mutation of a single amino acid (H89F) in the enzyme from the bacterium Rhodobacter sphaeroides [1,2].

Links to other databases: BRENDA, EXPASY, KEGG, Metacyc, CAS registry number: 1030840-68-6

References:

1. Louie, G.V., Bowman, M.E., Moffitt, M.C., Baiga, T.J., Moore, B.S. and Noel, J.P. Structural determinants and modulation of substrate specificity in phenylalanine-tyrosine ammonia-lyases. Chem. Biol. 13 (2006) 1327-1338. [PMID: 17185228]

2. Watts, K.T., Mijts, B.N., Lee, P.C., Manning, A.J. and Schmidt-Dannert, C. Discovery of a substrate selectivity switch in tyrosine ammonia-lyase, a member of the aromatic amino acid lyase family. Chem. Biol. 13 (2006) 1317-1326. [PMID: 17185227]

3. Schwede, T.F., Rétey, J. and Schulz, G.E. Crystal structure of histidine ammonia-lyase revealing a novel polypeptide modification as the catalytic electrophile. Biochemistry 38 (1999) 5355-5361. [PMID: 10220322]

[EC 4.3.1.23 created 2008 (EC 4.3.1.5 created 1965, part-incorporated 2008)]

EC 4.3.1.24

Accepted name: phenylalanine ammonia-lyase

Reaction: L-phenylalanine = trans-cinnamate + NH3

For diagram of reaction click here

Other name(s): phenylalanine deaminase; phenylalanine ammonium-lyase; PAL; L-phenylalanine ammonia-lyase; Phe ammonia-lyase

Systematic name: L-phenylalanine ammonia-lyase (trans-cinnamate-forming)

Comments: This enzyme is a member of the aromatic amino acid lyase family, other members of which are EC 4.3.1.3 (histidine ammonia-lyase) and EC 4.3.1.23 (tyrosine ammonia-lyase) and EC 4.3.1.25 (phenylalanine/tyrosine ammonia-lyase). The enzyme contains the cofactor 3,5-dihydro-5-methylidene-4H-imidazol-4-one (MIO), which is common to this family [3]. This unique cofactor is formed autocatalytically by cyclization and dehydration of the three amino-acid residues alanine, serine and glycine [9]. The enzyme from some species is highly specific for phenylalanine [7,8].

Links to other databases: BRENDA, EXPASY, KEGG, Metacyc, PDB, CAS registry number: 9024-28-6

References:

1. Koukol, J. and Conn, E.E. The metabolism of aromatic compounds in higher plants. IV. Purification and properties of the phenylalanine deaminase of Hordeum vulgare. J. Biol. Chem. 236 (1961) 2692-2698. [PMID: 14458851]

2. Young, M.R. and Neish, A.C. Properties of the ammonia-lyases deaminating phenylalanine and related compounds in Triticum sestivum and Pteridium aquilinum. Phytochemistry 5 (1966) 1121-1132.

3. Louie, G.V., Bowman, M.E., Moffitt, M.C., Baiga, T.J., Moore, B.S. and Noel, J.P. Structural determinants and modulation of substrate specificity in phenylalanine-tyrosine ammonia-lyases. Chem. Biol. 13 (2006) 1327-1338. [PMID: 17185228]

4. Calabrese, J.C., Jordan, D.B., Boodhoo, A., Sariaslani, S. and Vannelli, T. Crystal structure of phenylalanine ammonia lyase: multiple helix dipoles implicated in catalysis. Biochemistry 43 (2004) 11403-11416. [PMID: 15350127]

5. Ritter, H. and Schulz, G.E. Structural basis for the entrance into the phenylpropanoid metabolism catalyzed by phenylalanine ammonia-lyase. Plant Cell 16 (2004) 3426-3436. [PMID: 15548745]

6. Watts, K.T., Mijts, B.N., Lee, P.C., Manning, A.J. and Schmidt-Dannert, C. Discovery of a substrate selectivity switch in tyrosine ammonia-lyase, a member of the aromatic amino acid lyase family. Chem. Biol. 13 (2006) 1317-1326. [PMID: 17185227]

7. Appert, C., Logemann, E., Hahlbrock, K., Schmid, J. and Amrhein, N. Structural and catalytic properties of the four phenylalanine ammonia-lyase isoenzymes from parsley (Petroselinum crispum Nym.). Eur. J. Biochem. 225 (1994) 491-499. [PMID: 7925471]

8. Cochrane, F.C., Davin, L.B. and Lewis, N.G. The Arabidopsis phenylalanine ammonia lyase gene family: kinetic characterization of the four PAL isoforms. Phytochemistry 65 (2004) 1557-1564. [PMID: 15276452]

9. Schwede, T.F., Rétey, J. and Schulz, G.E. Crystal structure of histidine ammonia-lyase revealing a novel polypeptide modification as the catalytic electrophile. Biochemistry 38 (1999) 5355-5361. [PMID: 10220322]

[EC 4.3.1.24 created 2008 (EC 4.3.1.5 created 1965, part-incorporated 2008)]

EC 4.3.1.25

Accepted name: phenylalanine/tyrosine ammonia-lyase

Reaction: (1) L-phenylalanine = trans-cinnamate + NH3
(2) L-tyrosine = trans-p-hydroxycinnamate + NH3

Other name(s): PTAL; bifunctional PAL

Systematic name: L-phenylalanine(or L-tyrosine):trans-cinnamate(or trans-p-hydroxycinnamate) ammonia-lyase

Comments: This enzyme is a member of the aromatic amino acid lyase family, other members of which are EC 4.3.1.3 (histidine ammonia-lyase), EC 4.3.1.23 (tyrosine ammonia-lyase) and EC 4.3.1.24 (phenylalanine ammonia-lyase). The enzyme from some monocots, including maize, and from the yeast Rhodosporidium toruloides, deaminate L-phenylalanine and L-tyrosine with similar catalytic efficiency [3]. The enzyme contains the cofactor 3,5-dihydro-5-methylidene-4H-imidazol-4-one (MIO), which is common to this family [3]. This unique cofactor is formed autocatalytically by cyclization and dehydration of the three amino-acid residues alanine, serine and glycine [4].

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

References:

1. Rösler, J., Krekel, F., Amrhein, N. and Schmid, J. Maize phenylalanine ammonia-lyase has tyrosine ammonia-lyase activity. Plant Physiol. 113 (1997) 175-179. [PMID: 9008393]

2. Watts, K.T., Mijts, B.N., Lee, P.C., Manning, A.J. and Schmidt-Dannert, C. Discovery of a substrate selectivity switch in tyrosine ammonia-lyase, a member of the aromatic amino acid lyase family. Chem. Biol. 13 (2006) 1317-1326. [PMID: 17185227]

3. Louie, G.V., Bowman, M.E., Moffitt, M.C., Baiga, T.J., Moore, B.S. and Noel, J.P. Structural determinants and modulation of substrate specificity in phenylalanine-tyrosine ammonia-lyases. Chem. Biol. 13 (2006) 1327-1338. [PMID: 17185228]

4. Schwede, T.F., Rétey, J. and Schulz, G.E. Crystal structure of histidine ammonia-lyase revealing a novel polypeptide modification as the catalytic electrophile. Biochemistry 38 (1999) 5355-5361. [PMID: 10220322]

[EC 4.3.1.25 created 2008 (EC 4.3.1.5 created 1965, part-incorporated 2008)]

[EC 4.3.1.26 Transferred entry: chromopyrrolate synthase. Now EC 1.21.3.9, dichlorochromopyrrolate synthase (EC 4.3.1.26 created 2010, deleted 2013)]

EC 4.3.1.27

Accepted name: threo-3-hydroxy-D-aspartate ammonia-lyase

Reaction: threo-3-hydroxy-D-aspartate = oxaloacetate + NH3

Other name(s): D-threo-3-hydroxyaspartate dehydratase

Systematic name: threo-3-hydroxy-D-aspartate ammonia-lyase (oxaloacetate-forming)

Comments: A pyridoxal-phosphate protein. The enzyme, purified from the bacterium Delftia sp. HT23, also has activity against L-threo-3-hydroxyaspartate, L-erythro-3-hydroxyaspartate, and D-serine. Different from EC 4.3.1.20, erythro-3-hydroxy-L-aspartate ammonia-lyase and EC 4.3.1.16, threo-3-hydroxy-L-aspartate ammonia-lyase. Requires a divalent cation such as Mn2+, Co2+ or Ni2+.

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

References:

1. Maeda, T., Takeda, Y., Murakami, T., Yokota, A. and Wada, M. Purification, characterization and amino acid sequence of a novel enzyme, D-threo-3-hydroxyaspartate dehydratase, from Delftia sp. HT23. J. Biochem. 148 (2010) 705-712. [PMID: 20843822]

[EC 4.3.1.27 created 2011]

EC 4.3.1.28

Accepted name: L-lysine cyclodeaminase

Reaction: L-lysine = L-pipecolate + NH3

Other name(s): rapL (gene name); fkbL (gene name); tubZ (gene name); visC (gene name)

Systematic name: L-lysine ammonia-lyase (cyclizing; ammonia-forming)

Comments: Requires bound NAD+. The enzyme produces the non-proteinogenic amino acid L-pipecolate, which is incorporated into multiple secondary metabolite products, including rapamycin, tobulysin, virginiamycin and pristinamycin.

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

References:

1. Khaw, L.E., Bohm, G.A., Metcalfe, S., Staunton, J. and Leadlay, P.F. Mutational biosynthesis of novel rapamycins by a strain of Streptomyces hygroscopicus NRRL 5491 disrupted in rapL, encoding a putative lysine cyclodeaminase. J. Bacteriol. 180 (1998) 809-814. [PMID: 9473033]

2. Gatto, G.J., Jr., Boyne, M.T., 2nd, Kelleher, N.L. and Walsh, C.T. Biosynthesis of pipecolic acid by RapL, a lysine cyclodeaminase encoded in the rapamycin gene cluster. J. Am. Chem. Soc. 128 (2006) 3838-3847. [PMID: 16536560]

3. Tsotsou, G.E. and Barbirato, F. Biochemical characterisation of recombinant Streptomyces pristinaespiralis L-lysine cyclodeaminase. Biochimie 89 (2007) 591-604. [PMID: 17291665]

[EC 4.3.1.28 created 2012]

EC 4.3.1.29

Accepted name: D-glucosaminate-6-phosphate ammonia-lyase

Reaction: 2-amino-2-deoxy-D-gluconate 6-phosphate = 2-dehydro-3-deoxy-6-phospho-D-gluconate + NH3

Other name(s): DgaE; 6-phospho-D-glucosaminate ammonia-lyase (2-dehydro-3-deoxy-6-phospho-D-gluconate-forming)

Systematic name: 2-amino-2-deoxy-D-gluconate 6-phosphate ammonia-lyase (2-dehydro-3-deoxy-6-phospho-D-gluconate-forming)

Comments: The enzyme, from the bacterium Salmonella typhimurium, is involved in the degradation pathway of 2-amino-2-deoxy-D-gluconate.

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

References:

1. Miller, K.A., Phillips, R.S., Mrazek, J. and Hoover, T.R. Salmonella utilizes D-glucosaminate via a mannose family phosphotransferase system permease and associated enzymes. J. Bacteriol. 195 (2013) 4057-4066. [PMID: 23836865]

[EC 4.3.1.29 created 2013]

EC 4.3.1.30

Accepted name: dTDP-4-amino-4,6-dideoxy-D-glucose ammonia-lyase

Reaction: dTDP-4-amino-4,6-dideoxy-α-D-glucopyranose + S-adenosyl-L-methionine + reduced acceptor = dTDP-3-dehydro-4,6-dideoxy-α-D-glucopyranose + NH3 + L-methionine + 5'-deoxyadenosine + acceptor

For diagram of reaction click here.

Other name(s): desII (gene name); eryCV (gene name); MegCV

Systematic name: dTDP-4-amino-4,6-dideoxy-α-D-glucopyranose ammonia lyase (dTDP-3-dehydro-4,6-dideoxy-α-D-glucopyranose-forming)

Comments: The enzyme, which is a member of the 'AdoMet radical' (radical SAM) family, is involved in biosynthesis of TDP-α-D-desosamine. The reaction starts by the transfer of an electron from the reduced form of the enzyme's [4Fe-4S] cluster to S-adenosyl-L-methionine, spliting it into methionine and the radical 5-deoxyadenosin-5'-yl, which attacks the sugar substrate.

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

References:

1. Szu, P.H., Ruszczycky, M.W., Choi, S.H., Yan, F. and Liu, H.W. Characterization and mechanistic studies of DesII: a radical S-adenosyl-L-methionine enzyme involved in the biosynthesis of TDP-D-desosamine. J. Am. Chem. Soc. 131 (2009) 14030-14042. [PMID: 19746907]

2. Ruszczycky, M.W., Choi, S.H. and Liu, H.W. Stoichiometry of the redox neutral deamination and oxidative dehydrogenation reactions catalyzed by the radical SAM enzyme DesII. J. Am. Chem. Soc. 132 (2010) 2359-2369. [PMID: 20121093]

3. Ruszczycky, M.W., Choi, S.H., Mansoorabadi, S.O. and Liu, H.W. Mechanistic studies of the radical S-adenosyl-L-methionine enzyme DesII: EPR characterization of a radical intermediate generated during its catalyzed dehydrogenation of TDP-D-quinovose. J. Am. Chem. Soc. 133 (2011) 7292-7295. [PMID: 21513273]

[EC 4.3.1.30 created 2011]

EC 4.3.1.31

Accepted name: L-tryptophan ammonia lyase

Reaction: L-tryptophan = 3-indoleacrylate + ammonia

Glossary: 3-indoleacrylate = (2E)-3-(1H-indol-3-yl)prop-2-enoate

Other name(s): WAL

Systematic name: L-tryptophan ammonia-lyase (3-indoleacrylate-forming)

Comments: The enzyme, characterized from the bacterium Rubrivivax benzoatilyticus JA2, requires no cofactors. It acts on L-phenylalanine and L-glutamate with about 60% of the activity with L-tryptophan, and on L-tyrosine, glycine, and L-alanine with about 30% of the activity.

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

References:

1. Kumavath, R.N., Ramana ChV., Sasikala Ch, Barh, D., Kumar, A.P. and Azevedo, V. Isolation and characterization of L-tryptophan ammonia lyase from Rubrivivax benzoatilyticus strain JA2. Curr Protein Pept Sci 16 (2015) 775-781. [PMID: 25961404]

[EC 4.3.1.31 created 2016]


EC 4.3.2 Lyases Acting on Amides, Amidines, etc.

Contents

EC 4.3.2.1 argininosuccinate lyase
EC 4.3.2.2 adenylosuccinate lyase
EC 4.3.2.3 ureidoglycolate lyase
EC 4.3.2.4 purine imidazole-ring cyclase
EC 4.3.2.5 peptidylamidoglycolate lyase
EC 4.3.2.6 γ-L-glutamyl-butirosin B γ-glutamyl cyclotransferase

Entries

EC 4.3.2.1

Accepted name: argininosuccinate lyase

Reaction: 2-(Nω-L-arginino)succinate = fumarate + L-arginine

For diagram click here.

Other name(s): arginosuccinase; argininosuccinic acid lyase; arginine-succinate lyase; N-(L-argininosuccinate) arginine-lyase; ω-N-(L-arginino)succinate arginine-lyase

Systematic name: 2-(Nω-L-arginino)succinate arginine-lyase (fumarate-forming)

Links to other databases: BRENDA, EXPASY, GTD, KEGG, Metacyc, PDB, CAS registry number: 9027-34-3

References:

1. Davison, D.C. and Elliott, W.H. Enzymic reaction between arginine and fumarate in plant and animal tissue. Nature 169 (1952) 313-314. [PMID: 14910762]

[EC 4.3.2.1 created 1961]

EC 4.3.2.2

Accepted name: adenylosuccinate lyase

Reaction: (1) N6-(1,2-dicarboxyethyl)AMP = fumarate + AMP

(2) (S)-2-[5-amino-1-(5-phospho-D-ribosyl)imidazole-4-carboxamido]succinate = fumarate + 5-amino-1-(5-phospho-D-ribosyl)imidazole-4-carboxamide

For diagram click here and another example click here.

Other name(s): adenylosuccinase; succino AMP-lyase; N6-(1,2-dicarboxyethyl)AMP AMP-lyase; 6-N-(1,2-dicarboxyethyl)AMP AMP-lyase

Systematic name: N6-(1,2-dicarboxyethyl)AMP AMP-lyase (fumarate-forming)

Comments: Also acts on 1-(5-phosphoribosyl)-4-(N-succinocarboxamide)-5-aminoimidazole.

Links to other databases: BRENDA, EXPASY, GTD, KEGG, Metacyc, PDB, CAS registry number: 9027-81-0

References:

1. Carter, C.E. and Cohen, L.H. The preparation and properties of adenylosuccinase and adenylosuccinic acid. J. Biol. Chem. 222 (1956) 17-30. [PMID: 13366975]

[EC 4.3.2.2 created 1961, modified 2000]

EC 4.3.2.3

Accepted name: ureidoglycolate lyase

Reaction: (S)-ureidoglycolate = glyoxylate + urea

For diagram of reaction click here.

Other name(s): ureidoglycolatase (ambiguous); ureidoglycolase (ambiguous); ureidoglycolate hydrolase (misleading); (S)-ureidoglycolate urea-lyase

Systematic name: (S)-ureidoglycolate urea-lyase (glyoxylate-forming)

Comments: This microbial enzyme is involved in the degradation of ureidoglycolate, an intermediate of purine degradation. Not to be confused with EC 3.5.1.116, ureidoglycolate amidohydrolase, which releases ammonia rather than urea.

Links to other databases: BRENDA, EXPASY, GTD, KEGG, MetaCyc, CAS registry number: 9014-57-7

References:

1. Trijbels, F. and Vogels, G.D. Allantoate and ureidoglycolate degradation by Pseudomonas aeruginosa. Biochim. Biophys. Acta 132 (1967) 115-126. [PMID: 6030341]

2. Werner, A.K., Romeis, T. and Witte, C.P. Ureide catabolism in Arabidopsis thaliana and Escherichia coli. Nat. Chem. Biol. 6 (2010) 19-21. [PMID: 19935661]

[EC 4.3.2.3 created 1972, modified 2014]

EC 4.3.2.4

Accepted name: purine imidazole-ring cyclase

Reaction: DNA 4,6-diamino-5-formamidopyrimidine = DNA adenine + H2O

Other name(s): DNA-4,6-diamino-5-formamidopyrimidine C8-N9-lyase (cyclizing); DNA-4,6-diamino-5-formamidopyrimidine 8-C,9-N-lyase (cyclizing)

Systematic name: DNA-4,6-diamino-5-formamidopyrimidine C8-N9-lyase (cyclizing; DNA-adenine-forming)

Comments: Also acts on 2,6-diamino-5-formamido-3,4-dihydro-4-oxopyrimidine residues. Brings about the reclosure of the imidazole rings of purine residues damaged by γ-rays.

Links to other databases: BRENDA, EXPASY, KEGG, CAS registry number: 95990-28-6

References:

1. Chetsanga, C.J. and Grigorian, C. In situ enzymatic reclosure of opened imidazole rings of purines in DNA damaged by γ-irradiation. Proc. Natl. Acad. Sci. USA 82 (1985) 633-637. [PMID: 3856219]

[EC 4.3.2.4 created 1989]

EC 4.3.2.5

Accepted name: peptidylamidoglycolate lyase

Reaction: peptidylamidoglycolate = peptidyl amide + glyoxylate

Other name(s): α-hydroxyglycine amidating dealkylase; peptidyl-α-hydroxyglycine α-amidating lyase; HGAD; PGL; PAL; peptidylamidoglycolate peptidylamide-lyase

Systematic name: peptidylamidoglycolate peptidyl-amide-lyase (glyoxylate-forming)

Comments: The enzyme acts on the product of the reaction catalysed by EC 1.14.17.3 peptidylglycine monooxygenase, thus removing a terminal glycine residue and leaving a des-glycine peptide amide.

Links to other databases: BRENDA, EXPASY, KEGG, Metacyc, PDB, CAS registry number: 131689-50-4

References:

1. Katapodis, A.G., Ping, D. and May, S.W. A novel enzyme from bovine neurointermediate pituitary catalyzes dealkylation of α-hydroxyglycine derivatives, thereby functioning sequentially with peptidylglycine α-amidating monooxygenase in peptide amidation. Biochemistry 29 (1990) 6115-6120. [PMID: 2207061]

[EC 4.3.2.5 created 1992]

EC 4.3.2.6

Accepted name: γ-L-glutamyl-butirosin B γ-glutamyl cyclotransferase

Reaction: γ-L-glutamyl-butirosin B = butirosin B + 5-oxoproline

Glossary: γ-L-glutamyl-butirosin B = (1R,2R,3S,4R,6S)-6-amino-4-{[(2R)-4-(L-γ-glutamylamino)-2-hydroxybutanoyl]amino}-3-hydroxy-2-(α-D-ribofuranosyloxy)cyclohexyl

Other name(s): btrG (gene name)

Systematic name: γ-L-glutamyl-butirosin B γ-glutamyl cyclotransferase (5-oxoproline producing)

Comments: The enzyme catalyses the last step in the biosynthesis of the aminoglycoside antibiotic butirosin B. The enzyme acts as a cyclotransferase, cleaving the amide bond via transamidation using the α-amine of the terminal γ-L-glutamate of the side chain, releasing it as the cyclic 5-oxoproline.

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

References:

1. Llewellyn, N.M., Li, Y. and Spencer, J.B. Biosynthesis of butirosin: transfer and deprotection of the unique amino acid side chain. Chem. Biol. 14 (2007) 379-386. [PMID: 17462573]

[EC 4.3.2.6 created 2012]


EC 4.3.3 Amine-Lyases

Contents

EC 4.3.3.1 3-ketovalidoxylamine C-N-lyase
EC 4.3.3.2 strictosidine synthase
EC 4.3.3.3 deacetylisoipecoside synthase
EC 4.3.3.4 deacetylipecoside synthase

EC 4.3.3.5 4'-demethylrebeccamycin synthase
EC 4.3.3.6 pyridoxal 5'-phosphate synthase (glutamine hydrolysing)
EC 4.3.3.7 4-hydroxy-tetrahydrodipicolinate synthase


Entries

EC 4.3.3.1

Accepted name: 3-ketovalidoxylamine C-N-lyase

Reaction: 4-nitrophenyl-3-ketovalidamine = 4-nitroaniline + 5-D-(5/6)-5-C-(hydroxymethyl)-2,6-dihydroxycyclohex-2-en-1-one

Other name(s): 3-ketovalidoxylamine A C-N-lyase; p-nitrophenyl-3-ketovalidamine p-nitroaniline lyase; 4-nitrophenyl-3-ketovalidamine 4-nitroaniline-lyase

Systematic name: 4-nitrophenyl-3-ketovalidamine 4-nitroaniline-lyase [5-D-(5/6)-5-C-(hydroxymethyl)-2,6-dihydroxycyclohex-2-en-1-one-forming]

Comments: Requires Ca2+. Eliminates 4-nitroaniline from 4-nitrophenyl-3-ketovalidamine, or 4-nitrophenol from 4-nitrophenyl-α-D-3-dehydroglucoside. Involved in the degradation of the fungicide validamycin A by Flavobacterium saccharophilum.

Links to other databases: BRENDA, EXPASY, KEGG, Metacyc, CAS registry number: 99889-98-2

References:

1. Asano, N., Takeuchi, M., Ninomiya, K., Kameda, Y. and Matsui, K. Microbial degradation of validamycin A by Flavobacterium saccharophilum. Enzymatic cleavage of C-N linkage in validoxylamine A. J. Antibiot. 37 (1984) 859-867. [PMID: 6548220]

2. Takeuchi, M., Asano, N., Kameda, Y. and Matsui, K. Purification and properties of 3-ketovalidoxylamine A C-N lyase from Flavobacterium saccharophilum. J. Biochem. (Tokyo) 98 (1985) 1631-1638. [PMID: 4093450]

[EC 4.3.3.1 created 1989]

EC 4.3.3.2

Accepted name: strictosidine synthase

Reaction: 3-α(S)-strictosidine + H2O = tryptamine + secologanin

For diagram click here.

Other name(s): strictosidine synthetase; STR; 3-α(S)-strictosidine tryptamine-lyase

Systematic name: 3-α(S)-strictosidine tryptamine-lyase (secologanin-forming)

Comments: Catalyses a Pictet-Spengler reaction between the aldehyde group of secologanin and the amino group of tryptamine [4,5]. Involved in the biosynthesis of the monoterpenoid indole alkaloids.

Links to other databases: BRENDA, EXPASY, KEGG, Metacyc, PDB, CAS registry number: 69669-72-3

References:

1. Treimer, J.K. and Zenk, M.H. Purification and properties of strictosidine synthase, the key enzyme in indole alkaloid formation. Eur. J. Biochem. 101 (1979) 225-233. [PMID: 510306]

2. Kutchan, T.M. Strictosidine: from alkaloid to enzyme to gene. Phytochemistry 32 (1993) 493-506. [PMID: 7763429]

3. de Waal, A., Meijer, A.H. and Verpoorte, R. Strictosidine synthase from Catharanthus roseus: purification and characterization of multiple forms. Biochem. J. 306 (1995) 571-580. [PMID: 7887913]

4. Ruppert, M., Woll, J., Giritch, A., Genady, E., Ma, X. and Stöckigt, J. Functional expression of an ajmaline pathway-specific esterase from Rauvolfia in a novel plant-virus expression system. Planta 222 (2005) 888-898. [PMID: 16133216]

5. McCoy, E., Galan, M.C. and O'Connor, S.E. Substrate specificity of strictosidine synthase. Bioorg. Med. Chem. Lett. 16 (2006) 2475-2478. [PMID: 16481164]

6. Ma, X., Panjikar, S., Koepke, J., Loris, E. and Stöckigt, J. The structure of Rauvolfia serpentina strictosidine synthase is a novel six-bladed β-propeller fold in plant proteins. Plant Cell 18 (2006) 907-920. [PMID: 16531499]

[EC 4.3.3.2 created 1990]

EC 4.3.3.3

Accepted name: deacetylisoipecoside synthase

Reaction: deacetylisoipecoside + H2O = dopamine + secologanin

For diagram click here.

Glossary: dopamine = 4-(2-aminoethyl)benzene-1,2-diol

Other name(s): deacetylisoipecoside dopamine-lyase

Systematic name: deacetylisoipecoside dopamine-lyase (secologanin-forming)

Comments: The enzyme from the leaves of Alangium lamarckii differs in enantiomeric specificity from EC 4.3.3.4 deacetylipecoside synthase. The product is rapidly converted to demethylisoalangiside.

Links to other databases: BRENDA, EXPASY, KEGG, Metacyc, CAS registry number: 192827-94-4

References:

1. DeEknamkul, W., Ounaroon, A., Tanahashi, T., Kutchan, T. and Zenk, M.H. Enzymatic condensation of dopamine and secologanin by cell-free extracts of Alangium lamarckii. Phytochemistry 45 (1997) 477-484.

[EC 4.3.3.3 created 2000]

EC 4.3.3.4

Accepted name: deacetylipecoside synthase

Reaction: deacetylipecoside + H2O = dopamine + secologanin

For diagram click here.

Glossary: dopamine = 4-(2-aminoethyl)benzene-1,2-diol

Other name(s): deacetylipecoside dopamine-lyase

Systematic name: deacetylipecoside dopamine-lyase (secologanin-forming)

Comments: The enzyme from the leaves of Alangium lamarckii differs in enantiomeric specificity from EC 4.3.3.3 deacetylisoipecoside synthase. The product is rapidly converted to demethylalangiside.

Links to other databases: BRENDA, EXPASY, KEGG, Metacyc, CAS registry number: 192827-93-3

References:

1. DeEknamkul, W., Ounaroon, A., Tanahashi, T., Kutchan, T. and Zenk, M.H. Enzymatic condensation of dopamine and secologanin by cell-free extracts of Alangium lamarckii. Phytochemistry 45 (1997) 477-484.

[EC 4.3.3.4 created 2000]

EC 4.3.3.5

Accepted name: 4'-demethylrebeccamycin synthase

Reaction: 4'-O-demethylrebeccamycin + H2O = dichloro-arcyriaflavin A + β-D-glucose

For diagram of reaction click here

Glossary: dichloro-arcyriaflavin A = rebeccamycin aglycone

Other name(s): arcyriaflavin A N-glycosyltransferase; RebG

Systematic name: 4'-demethylrebeccamycin D-glucose-lyase

Comments: This enzyme catalyses a step in the biosynthesis of rebeccamycin, an indolocarbazole alkaloid produced by the bacterium Lechevalieria aerocolonigenes. The enzyme is a glycosylase, and acts in the reverse direction to that shown. It has a wide substrate range, and was shown to glycosylate several substrates, including the staurosporine aglycone, EJG-III-108A, J-104303, 6-N-methyl-arcyriaflavin C and indolo-[2,3-a]-carbazole [1,2].

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

References:

1. Ohuchi, T., Ikeda-Araki, A., Watanabe-Sakamoto, A., Kojiri, K., Nagashima, M., Okanishi, M. and Suda, H. Cloning and expression of a gene encoding N-glycosyltransferase (ngt) from Saccharothrix aerocolonigenes ATCC39243. J. Antibiot. (Tokyo) 53 (2000) 393-403. [PMID: 10866221]

2. Zhang, C., Albermann, C., Fu, X., Peters, N.R., Chisholm, J.D., Zhang, G., Gilbert, E.J., Wang, P.G., Van Vranken, D.L. and Thorson, J.S. RebG- and RebM-catalyzed indolocarbazole diversification. Chembiochem 7 (2006) 795-804. [PMID: 16575939]

[EC 4.3.3.5 created 2010]

EC 4.3.3.6

Accepted name: pyridoxal 5'-phosphate synthase (glutamine hydrolysing)

Reaction: D-ribose 5-phosphate + D-glyceraldehyde 3-phosphate + L-glutamine = pyridoxal 5'-phosphate + L-glutamate + 3 H2O + phosphate (overall reaction)
(1a) L-glutamine + H2O = L-glutamate + NH3
(1b) D-ribose 5-phosphate + D-glyceraldehyde 3-phosphate + NH3 = pyridoxal 5'-phosphate + 4 H2O + phosphate

Other name(s): PdxST; pyridoxal 5'-phosphate synthase (glutamine hydrolyzing)

Systematic name: D-ribose 5-phosphate,D-glyceraldehyde 3-phosphate pyridoxal 5'-phosphate-lyase

Comments: The ammonia is provided by the glutaminase subunit and channeled to the active site of the lyase subunit by a 100 Å tunnel. The enzyme can also use ribulose 5-phosphate and dihydroxyacetone phosphate. The enzyme complex is found in aerobic bacteria, archaea, fungi and plants.

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

References:

1. Burns, K.E., Xiang, Y., Kinsland, C.L., McLafferty, F.W. and Begley, T.P. Reconstitution and biochemical characterization of a new pyridoxal-5'-phosphate biosynthetic pathway. J. Am. Chem. Soc. 127 (2005) 3682-3683. [PMID: 15771487]

2. Raschle, T., Amrhein, N. and Fitzpatrick, T.B. On the two components of pyridoxal 5'-phosphate synthase from Bacillus subtilis. J. Biol. Chem. 280 (2005) 32291-32300. [PMID: 16030023]

3. Strohmeier, M., Raschle, T., Mazurkiewicz, J., Rippe, K., Sinning, I., Fitzpatrick, T.B. and Tews, I. Structure of a bacterial pyridoxal 5'-phosphate synthase complex. Proc. Natl. Acad. Sci. USA 103 (2006) 19284-19289. [PMID: 17159152]

4. Raschle, T., Arigoni, D., Brunisholz, R., Rechsteiner, H., Amrhein, N. and Fitzpatrick, T.B. Reaction mechanism of pyridoxal 5'-phosphate synthase. Detection of an enzyme-bound chromophoric intermediate. J. Biol. Chem. 282 (2007) 6098-6105. [PMID: 17189272]

5. Hanes, J.W., Keresztes, I. and Begley, T.P. Trapping of a chromophoric intermediate in the Pdx1-catalyzed biosynthesis of pyridoxal 5'-phosphate. Angew. Chem. Int. Ed. Engl. 47 (2008) 2102-2105. [PMID: 18260082]

6. Hanes, J.W., Burns, K.E., Hilmey, D.G., Chatterjee, A., Dorrestein, P.C. and Begley, T.P. Mechanistic studies on pyridoxal phosphate synthase: the reaction pathway leading to a chromophoric intermediate. J. Am. Chem. Soc. 130 (2008) 3043-3052. [PMID: 18271580]

7. Hanes, J.W., Keresztes, I. and Begley, T.P. 13C NMR snapshots of the complex reaction coordinate of pyridoxal phosphate synthase. Nat. Chem. Biol. 4 (2008) 425-430. [PMID: 18516049]

8. Wallner, S., Neuwirth, M., Flicker, K., Tews, I. and Macheroux, P. Dissection of contributions from invariant amino acids to complex formation and catalysis in the heteromeric pyridoxal 5-phosphate synthase complex from Bacillus subtilis. Biochemistry 48 (2009) 1928-1935. [PMID: 19152323]

[EC 4.3.3.6 created 2011]

EC 4.3.3.7

Accepted name: 4-hydroxy-tetrahydrodipicolinate synthase

Reaction: pyruvate + L-aspartate-4-semialdehyde = (2S,4S)-4-hydroxy-2,3,4,5-tetrahydrodipicolinate + H2O

For diagram of reaction click here.

Glossary: (2S,4S)-4-hydroxy-2,3,4,5-tetrahydrodipicolinate = (2S,4S)-4-hydroxy-2,3,4,5-tetrahydropyridine-2,6-dicarboxylate

Other name(s): dihydrodipicolinate synthase (incorrect); dihydropicolinate synthetase (incorrect); dihydrodipicolinic acid synthase (incorrect); L-aspartate-4-semialdehyde hydro-lyase (adding pyruvate and cyclizing); dapA (gene name).

Systematic name: L-aspartate-4-semialdehyde hydro-lyase [adding pyruvate and cyclizing; (2S,4S)-4-hydroxy-2,3,4,5-tetrahydrodipicolinate-forming]

Comments: Studies of the enzyme from the bacterium Escherichia coli have shown that the reaction can be divided into three consecutive steps: Schiff base formation between pyruvate and an active-site lysine, the addition of L-aspartate-semialdehyde, and finally transimination leading to cyclization with simultaneous dissociation of the product.

Links to other databases: BRENDA, EXPASY, KEGG, Metacyc, CAS registry number: 9055-59-8

References:

1. Yugari, Y. and Gilvarg, C. The condensation step in diaminopimelate synthesis. J. Biol. Chem. 240 (1965) 4710-4716. [PMID: 5321309]

2. Blickling, S., Renner, C., Laber, B., Pohlenz, H.D., Holak, T.A. and Huber, R. Reaction mechanism of Escherichia coli dihydrodipicolinate synthase investigated by X-ray crystallography and NMR spectroscopy. Biochemistry 36 (1997) 24-33. [PMID: 8993314]

3. Devenish, S.R., Blunt, J.W. and Gerrard, J.A. NMR studies uncover alternate substrates for dihydrodipicolinate synthase and suggest that dihydrodipicolinate reductase is also a dehydratase. J Med Chem 53 (2010) 4808-4812. [PMID: 20503968]

4. Soares da Costa, T.P., Muscroft-Taylor, A.C., Dobson, R.C., Devenish, S.R., Jameson, G.B. and Gerrard, J.A. How essential is the 'essential' active-site lysine in dihydrodipicolinate synthase. Biochimie 92 (2010) 837-845. [PMID: 20353808]

[EC 4.3.3.7 created 1972 as EC 4.2.1.52, transferred 2012 to EC 4.3.3.7]


EC 4.3.99 Other Carbon-Nitrogen Lyases

Contents

EC 4.3.99.1 now EC 4.2.1.104 cyanate hydratase
EC 4.3.99.2 carboxybiotin decarboxylase
EC 4.3.99.3 7-carboxy-7-deazaguanine synthase
EC 4.3.99.4 choline trimethylamine-lyase


[EC 4.3.99.1 Transferred entry: now EC 4.2.1.104 cyanate hydratase (EC 4.3.99.1 created 1972 as EC 3.5.5.3, transferred 1990 to EC 4.3.99.1, deleted 2001)]

EC 4.3.99.2

Accepted name: carboxybiotin decarboxylase

Reaction: a carboxybiotinyl-[protein] + n Na+in + H+out = CO2 + a biotinyl-[protein] + n Na+out (n = 1—2)

For diagram of the reaction click here

Other name(s): MadB; carboxybiotin protein decarboxylase

Systematic name: carboxybiotinyl-[protein] carboxy-lyase

Comments: The integral membrane protein MadB from the anaerobic bacterium Malonomonas rubra is a component of the multienzyme complex EC 4.1.1.89, biotin-dependent malonate decarboxylase. The free energy of the decarboxylation reaction is used to pump Na+ out of the cell. The enzyme is a member of the Na+-translocating decarboxylase family, other members of which include EC 4.1.1.3 (oxaloacetate decarboxylase) and EC 4.1.1.41 (methylmalonyl-CoA decarboxylase) [2].

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

References:

1. Berg, M., Hilbi, H. and Dimroth, P. Sequence of a gene cluster from Malonomonas rubra encoding components of the malonate decarboxylase Na+ pump and evidence for their function. Eur. J. Biochem. 245 (1997) 103-115. [PMID: 9128730]

2. Dimroth, P. and Hilbi, H. Enzymic and genetic basis for bacterial growth on malonate. Mol. Microbiol. 25 (1997) 3-10. [PMID: 11902724]

[EC 4.3.99.2 created 2008]

EC 4.3.99.3

Accepted name: 7-carboxy-7-deazaguanine synthase

Reaction: 6-carboxy-5,6,7,8-tetrahydropterin = 7-carboxy-7-carbaguanine + NH3

For diagram of reaction click here.

Glossary: 7-carboxy-7-carbaguanine = 7-carboxy-7-deazaguanine

Other name(s): 7-carboxy-7-carbaguanine synthase; queE (gene name)

Systematic name: 6-carboxy-5,6,7,8-tetrahydropterin ammonia-lyase

Comments: Requires Mg2+. The enzyme is a member of the superfamily of S-adenosyl-L-methionine-dependent radical (radical AdoMet) enzymes. Binds a [4Fe-4S] cluster that is coordinated by 3 cysteines and an exchangeable S-adenosyl-L-methionine molecule. The S-adenosyl-L-methionine is catalytic as it is regenerated at the end of the reaction. The reaction is part of the biosynthesis pathway of queuosine.

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

References:

1. McCarty, R.M., Somogyi, A., Lin, G., Jacobsen, N.E. and Bandarian, V. The deazapurine biosynthetic pathway revealed: in vitro enzymatic synthesis of preQ0 from guanosine 5'-triphosphate in four steps. Biochemistry 48 (2009) 3847-3852. [PMID: 19354300]

2. McCarty, R.M., Krebs, C. and Bandarian, V. Spectroscopic, steady-state kinetic, and mechanistic characterization of the radical SAM enzyme QueE, which catalyzes a complex cyclization reaction in the biosynthesis of 7-deazapurines. Biochemistry 52 (2013) 188-198. [PMID: 23194065]

[EC 4.3.99.3 created 2012]

EC 4.3.99.4

Accepted name: choline trimethylamine-lyase

Reaction: choline = trimethylamine + acetaldehyde

Other name(s): cutC (gene name)

Systematic name: choline trimethylamine-lyase (acetaldehyde-forming)

Comments: The enzyme utilizes a glycine radical to break the C-N bond in choline. Found in choline-degrading anaerobic bacteria.

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

References:

1. Craciun, S. and Balskus, E.P. Microbial conversion of choline to trimethylamine requires a glycyl radical enzyme. Proc. Natl. Acad. Sci. USA 109 (2012) 21307-21312. [PMID: 23151509]

[EC 4.3.99.4 created 2013]


Continued with EC 4.4.1.1 to EC 4.99.1.2
Return to EC 4 home page
Return to Enzymes home page
Return to IUBMB Biochemical Nomenclature home page