Enzyme Nomenclature

EC 4.2.1 (continued)

Hydro-Lyases

Continued from EC 4.2.1.1 to EC 4.2.1.50

Continued with EC 4.2.1.101 to EC 4.2.1.175

Contents

EC 4.2.1.51 prephenate dehydratase
EC 4.2.1.52 now EC 4.3.3.7
EC 4.2.1.53 oleate hydratase
EC 4.2.1.54 lactoyl-CoA dehydratase
EC 4.2.1.55 3-hydroxybutyryl-CoA dehydratase
EC 4.2.1.56 itaconyl-CoA hydratase
EC 4.2.1.57 isohexenylglutaconyl-CoA hydratase
EC 4.2.1.58 deleted now covered by EC 4.2.1.59
EC 4.2.1.59 3-hydroxyacyl-[acyl-carrier-protein] dehydratase
EC 4.2.1.60 deleted now covered by EC 4.2.1.59
EC 4.2.1.61 deleted now covered by EC 4.2.1.59
EC 4.2.1.62 5α-hydroxysteroid dehydratase
EC 4.2.1.63 now EC 3.3.2.3
EC 4.2.1.64 now EC 3.3.2.3
EC 4.2.1.65 3-cyanoalanine hydratase
EC 4.2.1.66 cyanide hydratase
EC 4.2.1.67 D-fuconate dehydratase
EC 4.2.1.68 L-fuconate dehydratase
EC 4.2.1.69 cyanamide hydratase
EC 4.2.1.70 pseudouridylate synthase
EC 4.2.1.71 acetylenecarboxylate hydratase
EC 4.2.1.71 identical to EC 4.2.1.27
EC 4.2.1.72 now EC 4.1.1.78
EC 4.2.1.73 protoaphin-aglucone dehydratase (cyclizing)
EC 4.2.1.74 long-chain-enoyl-CoA hydratase
EC 4.2.1.75 uroporphyrinogen-III synthase
EC 4.2.1.76 UDP-glucose 4,6-dehydratase
EC 4.2.1.77 trans-L-3-hydroxyproline dehydratase
EC 4.2.1.78 (S)-norcoclaurine synthase
EC 4.2.1.79 2-methylcitrate dehydratase
EC 4.2.1.80 2-oxopent-4-enoate hydratase
EC 4.2.1.81 D(–)-tartrate dehydratase
EC 4.2.1.82 xylonate dehydratase
EC 4.2.1.83 4-oxalmesaconate hydratase
EC 4.2.1.84 nitrile hydratase
EC 4.2.1.85 dimethylmaleate hydratase
EC 4.2.1.86 deleted identical to EC 4.2.1.98
EC 4.2.1.87 octopamine dehydratase
EC 4.2.1.88 synephrine dehydratase
EC 4.2.1.89 deleted, due to EC 2.8.3.21 and EC 4.2.1.149
EC 4.2.1.90 L-rhamnonate dehydratase
EC 4.2.1.91 arogenate dehydratase
EC 4.2.1.92 hydroperoxide dehydratase
EC 4.2.1.93 ATP-dependent NAD(P)H-hydrate dehydratase
EC 4.2.1.94 scytalone dehydratase
EC 4.2.1.95 kievitone hydratase
EC 4.2.1.96 4a-hydroxytetrahydrobiopterin dehydratase
EC 4.2.1.97 phaseollidin hydratase
EC 4.2.1.98 16α-hydroxyprogesterone dehydratase
EC 4.2.1.99 2-methylisocitrate dehydratase
EC 4.2.1.100 cyclohexa-1,5-dienecarbonyl-CoA hydratase
See the following file for:
EC 4.2.1.101 to EC 4.2.1.175

Entries

EC 4.2.1.51

Accepted name: prephenate dehydratase

Reaction: prephenate = phenylpyruvate + H2O + CO2

For diagram click here.

Other name(s): prephenate hydro-lyase (decarboxylating)

Systematic name: prephenate hydro-lyase (decarboxylating; phenylpyruvate-forming)

Comments: This enzyme in the enteric bacteria also possesses chorismate mutase (EC 5.4.99.5) activity, and converts chorismate into prephenate.

Links to other databases: BRENDA, EXPASY, KEGG, Metacyc, PDB, CAS registry number: 9044-88-6

References:

1. Cerutti, P. and Guroff, G. Enzymatic formation of phenylpyruvic acid in Pseudomonas sp. (ATCC 11299A) and its regulation. J. Biol. Chem. 240 (1965) 3034-3048. [PMID: 14342329]

2. Cotton, R.G.H. and Gibson, F. The biosynthesis of phenylalanine and tyrosine; enzymes converting chorismic acid into prephenic acid and their relationships to prephenate dehydratase and prephenate dehydrogenase. Biochim. Biophys. Acta 100 (1965) 76-88.

3. Schmidt, J.C. and Zalkin, H. Chorismate mutase-prephenate dehydratase. Partial purification and properties of the enzyme from Salmonella typhimurium. Biochemistry 8 (1969) 174-181.

[EC 4.2.1.51 created 1972]

[EC 4.2.1.52 Transferred entry: dihydrodipicolinate synthase. Now EC 4.3.3.7, 4-hydroxy-2,3,4,5-tetrahydrodipicolinate synthase. (EC 4.2.1.52 created 1972, transferred 2012 to EC 4.3.3.7, deleted 2012)]

EC 4.2.1.53

Accepted name: oleate hydratase

Reaction: (R)-10-hydroxystearate = oleate + H2O

Other name(s): (R)-10-hydroxystearate 10-hydro-lyase

Systematic name: (R)-10-hydroxystearate 10-hydro-lyase (oleate-forming)

Comments: Acts on a number of 10-hydroxy acids.

Links to other databases: BRENDA, EXPASY, KEGG, Metacyc, CAS registry number: 9073-51-2

References:

1. Davis, E.N., Wallen, L.L., Goodwin, J.C., Rohwedder, W.K. and Rhodes, R.A. Microbial hydration of cis-9-alkenoic acids. Lipids 4 (1969) 356-362. [PMID: 5823715]

2. Gotouda, H., Takatori, T., Terazawa, K., Nagao, M. and Tarao, H. The mechanism of experimental adipocere formation: hydration and dehydrogenation in microbial synthesis of hydroxy and oxo fatty acids. Forensic Sci. Int. 37 (1988) 249-257. [PMID: 3410394]

3. Niehaus, W.G., Jr., Kisic, A., Torkelson, A., Bednarczyk, D.J. and Schroepfer, G.J., Jr., Stereospecific hydration of the δ9 double bond of oleic acid. J. Biol. Chem. 245 (1970) 3790-3797. [PMID: 5492948]

[EC 4.2.1.53 created 1972]

EC 4.2.1.54

Accepted name: lactoyl-CoA dehydratase

Reaction: (R)-lactoyl-CoA = acryloyl-CoA + H2O

Other name(s): lactoyl coenzyme A dehydratase; lactyl-coenzyme A dehydrase; lactyl CoA dehydratase; acrylyl coenzyme A hydratase; lactoyl-CoA hydro-lyase

Systematic name: (R)-lactoyl-CoA hydro-lyase (acryloyl-CoA-forming)

Comments: A bacterial enzyme that is involved in propanoate fermentation (also known as the acrylate pathway).

Links to other databases: BRENDA, EXPASY, KEGG, Metacyc, UM-BBD, CAS registry number: 9031-12-3

References:

1. Baldwin, R.L., Wood, W.A. and Emery, R.S. Lactate metabolism by Peptostreptococcus elsdenii: evidence for lactyl coenzyme a dehydrase. Biochim. Biophys. Acta 97 (1965) 202-213. [PMID: 14292829]

2. Schweiger, G. and Buckel, W. On the dehydration of (R)-lactate in the fermentation of alanine to propionate by Clostridium propionicum. FEBS Lett 171 (1984) 79-84. [PMID: 6586495]

3. Kuchta, R.D. and Abeles, R.H. Lactate reduction in Clostridium propionicum. Purification and properties of lactyl-CoA dehydratase. J. Biol. Chem. 260 (1985) 13181-13189. [PMID: 4055736]

4. Kuchta, R.D., Hanson, G.R., Holmquist, B. and Abeles, R.H. Fe-S centers in lactyl-CoA dehydratase. Biochemistry 25 (1986) 7301-7307. [PMID: 3026450]

5. Hofmeister, A.E. and Buckel, W. (R)-lactyl-CoA dehydratase from Clostridium propionicum. Stereochemistry of the dehydration of (R)-2-hydroxybutyryl-CoA to crotonyl-CoA. Eur. J. Biochem. 206 (1992) 547-552. [PMID: 1597194]

[EC 4.2.1.54 created 1972, modified 2012]

EC 4.2.1.55

Accepted name: 3-hydroxybutyryl-CoA dehydratase

Reaction: (3R)-3-hydroxybutanoyl-CoA = crotonoyl-CoA + H2O

For diagram of reaction click here.

Other name(s): D-3-hydroxybutyryl coenzyme A dehydratase; D-3-hydroxybutyryl-CoA dehydratase; enoyl coenzyme A hydrase (D); (3R)-3-hydroxybutanoyl-CoA hydro-lyase

Systematic name: (3R)-3-hydroxybutanoyl-CoA hydro-lyase (crotonoyl-CoA-forming)

Comments: Also acts on crotonoyl thioesters of pantetheine and acyl-carrier protein.

Links to other databases: BRENDA, EXPASY, KEGG, Metacyc, PDB, CAS registry number: 37290-82-7

References:

1. Moskowitz, G.J. and Merrick, J.M. Metabolism of poly-β-hydroxybutyrate. II. Enzymatic synthesis of D-(–)-β hydroxybutyryl coenzyme A by an enoyl hydrase from Rhodospirillum rubrum. Biochemistry 8 (1969) 2748-2755. [PMID: 5808333]

[EC 4.2.1.55 created 1972]

EC 4.2.1.56

Accepted name: itaconyl-CoA hydratase

Reaction: citramalyl-CoA = itaconyl-CoA + H2O

Other name(s): itaconyl coenzyme A hydratase; citramalyl-CoA hydro-lyase

Systematic name: citramalyl-CoA hydro-lyase (itaconyl-CoA-forming)

Links to other databases: BRENDA, EXPASY, KEGG, Metacyc, CAS registry number: 37290-83-8

References:

1. Cooper, R.A. and Kornberg, H.L. The utilization of itaconate by Pseudomonas sp. Biochem. J. 91 (1964) 82-91. [PMID: 4284209]

[EC 4.2.1.56 created 1972]

EC 4.2.1.57

Accepted name: isohexenylglutaconyl-CoA hydratase

Reaction: 3-hydroxy-3-(4-methylpent-3-en-1-yl)glutaryl-CoA = 3-(4-methylpent-3-en-1-yl)pent-2-enedioyl-CoA + H2O

Other name(s): 3-hydroxy-3-isohexenylglutaryl-CoA-hydrolase; isohexenylglutaconyl coenzyme A hydratase; β-isohexenylglutaconyl-CoA-hydratase; 3-hydroxy-3-(4-methylpent-3-en-1-yl)glutaryl-CoA hydro-lyase

Systematic name: 3-hydroxy-3-(4-methylpent-3-en-1-yl)glutaryl-CoA hydro-lyase [3-(4-methylpent-3-en-1-yl)pent-2-enedioyl-CoA-forming]

Comments: Also acts on dimethylacryloyl-CoA and farnesoyl-CoA.

Links to other databases: BRENDA, EXPASY, KEGG, Metacyc, UM-BBD, CAS registry number: 37290-84-9

References:

1. Seubert, W. and Fass, E. Untersuchungen über den bakterielle Abbau von Isoprenoiden. IV. Reinigung und Eigenschaftender β-Isohexenylglutaconyl-CoA-hydratase und β-Hydroxy-β-isohexenylglutaryl-CoA-lyase. Biochem. Z. 341 (1964) 23-34.

[EC 4.2.1.57 created 1972]

[EC 4.2.1.58 Deleted entry: crotonoyl-[acyl-carrier-protein] hydratase. The reaction described is covered by EC 4.2.1.59. (EC 4.2.1.58 created 1972, deleted 2012)]

EC 4.2.1.59

Accepted name: 3-hydroxyacyl-[acyl-carrier-protein] dehydratase

Reaction: a (3R)-3-hydroxyacyl-[acyl-carrier protein] = a trans-2-enoyl-[acyl-carrier protein] + H2O

Other name(s): fabZ (gene name); fabA (gene name); D-3-hydroxyoctanoyl-[acyl carrier protein] dehydratase; D-3-hydroxyoctanoyl-acyl carrier protein dehydratase; β-hydroxyoctanoyl-acyl carrier protein dehydrase; β-hydroxyoctanoyl thioester dehydratase; β-hydroxyoctanoyl-ACP-dehydrase; (3R)-3-hydroxyoctanoyl-[acyl-carrier-protein] hydro-lyase; (3R)-3-hydroxyoctanoyl-[acyl-carrier-protein] hydro-lyase (oct-2-enoyl-[acyl-carrier protein]-forming); 3-hydroxyoctanoyl-[acyl-carrier-protein] dehydratase

Systematic name: (3R)-3-hydroxyacyl-[acyl-carrier protein] hydro-lyase (trans-2-enoyl-[acyl-carrier protein]-forming)

Comments: This enzyme is responsible for the dehydration step of the dissociated (type II) fatty-acid biosynthesis system that occurs in plants and bacteria. The enzyme uses fatty acyl thioesters of ACP in vivo. Different forms of the enzyme may have preferences for substrates with different chain length. For example, the activity of FabZ, the ubiquitous enzyme in bacteria, decreases with increasing chain length. Gram-negative bacteria that produce unsaturated fatty acids, such as Escherichia coli, have another form (FabA) that prefers intermediate chain length, and also catalyses EC 5.3.3.14, trans-2-decenoyl-[acyl-carrier protein] isomerase. Despite the differences both forms can catalyse all steps leading to the synthesis of palmitate (C16:0). FabZ, but not FabA, can also accept unsaturated substrates [4].

Links to other databases: BRENDA, EXPASY, KEGG, Metacyc, PDB, CAS registry number: 9030-85-7

References:

1. Mizugaki, M., Swindell, A.C. and Wkil, S.J. Intermediate- and long-chain β-hydroxyacyl-ACP dehydrases from E. coli fatty acid synthetase. Biochem. Biophys. Res. Commun. 33 (1968) 520-527. [PMID: 4881058]

2. Sharma, A., Henderson, B.S., Schwab, J.M. and Smith, J.L. Crystallization and preliminary X-ray analysis of β-hydroxydecanoyl thiol ester dehydrase from Escherichia coli. J. Biol. Chem. 265 (1990) 5110-5112. [PMID: 2180957]

3. Mohan, S., Kelly, T.M., Eveland, S.S., Raetz, C.R. and Anderson, M.S. An Escherichia coli gene (FabZ) encoding (3R)-hydroxymyristoyl acyl carrier protein dehydrase. Relation to fabA and suppression of mutations in lipid A biosynthesis. J. Biol. Chem. 269 (1994) 32896-32903. [PMID: 7806516]

4. Heath, R.J. and Rock, C.O. Roles of the FabA and FabZ β-hydroxyacyl-acyl carrier protein dehydratases in Escherichia coli fatty acid biosynthesis. J. Biol. Chem. 271 (1996) 27795-27801. [PMID: 8910376]

[EC 4.2.1.59 created 1972, modified 2012]

[EC 4.2.1.60 Deleted entry: 3-hydroxydecanoyl-[acyl-carrier-protein] dehydratase. The reaction described is covered by EC 4.2.1.59. (EC 4.2.1.60 created 1972, modified 2006, deleted 2012)]

[EC 4.2.1.61 Deleted entry: 3-hydroxypalmitoyl-[acyl-carrier-protein] dehydratase. The reaction described is covered by EC 4.2.1.59. (EC 4.2.1.61 created 1972, deleted 2012)]

EC 4.2.1.62

Accepted name: 5α-hydroxysteroid dehydratase

Reaction: 5α-ergosta-7,22-diene-3β,5-diol = ergosterol + H2O

Other name(s): 5α-ergosta-7,22-diene-3β,5-diol 5,6-hydro-lyase

Systematic name: 5α-ergosta-7,22-diene-3β,5-diol 5,6-hydro-lyase (ergosterol-forming)

Links to other databases: BRENDA, EXPASY, KEGG, Metacyc, CAS registry number: 9075-27-8

References:

1. Topham, R.W. and Gaylor, J.L. Isolation and purification of a 5α-hydroxysterol dehydrase of yeast. J. Biol. Chem. 245 (1970) 2319-2327. [PMID: 5442273]

[EC 4.2.1.62 created 1972]

[EC 4.2.1.63 Transferred entry: now EC 3.3.2.3 epoxide hydrolase (EC 4.2.1.63 created 1972, deleted 1978)]

[EC 4.2.1.64 Transferred entry: now EC 3.3.2.3 epoxide hydrolase (EC 4.2.1.64 created 1972, deleted 1978)]

EC 4.2.1.65

Accepted name: 3-cyanoalanine hydratase

Reaction: L-asparagine = 3-cyanoalanine + H2O

Other name(s): β-cyanoalanine hydrolase; β-cyanoalanine hydratase; β-CNAla hydrolase; β-CNA nitrilase; L-asparagine hydro-lyase

Systematic name: L-asparagine hydro-lyase (3-cyanoalanine-forming)

Links to other databases: BRENDA, EXPASY, KEGG, Metacyc, CAS registry number: 37259-64-6

References:

1. Castric, P.A., Farnden, K.J.F. and Conn, E.E. Cyanide metabolism in higher plants. V. The formation of asparagine from β-cyanoalanine. Arch. Biochem. Biophys. 152 (1972) 62-69. [PMID: 4627358]

[EC 4.2.1.65 created 1976]

EC 4.2.1.66

Accepted name: cyanide hydratase

Reaction: formamide = cyanide + H2O

Other name(s): formamide dehydratase; formamide hydro-lyase

Systematic name: formamide hydro-lyase (cyanide-forming)

Links to other databases: BRENDA, EXPASY, KEGG, Metacyc, CAS registry number: 37292-83-4

References:

1. Fry, W.E. and Millar, R.L. Cyanide degradion by an enzyme from Stemphylium loti. Arch. Biochem. Biophys. 151 (1972) 468-474. [PMID: 5065258]

[EC 4.2.1.66 created 1976]

EC 4.2.1.67

Accepted name: D-fuconate dehydratase

Reaction: D-fuconate = 2-dehydro-3-deoxy-D-fuconate + H2O

Other name(s): D-fuconate hydro-lyase

Systematic name: D-fuconate hydro-lyase (2-dehydro-3-deoxy-D-fuconate-forming)

Comments: Also acts on L-arabinonate.

Links to other databases: BRENDA, EXPASY, KEGG, Metacyc, CAS registry number: 9076-59-9

References:

1. Dahms, A.S. and Anderson, R.L. D-Fucose metabolism in a pseudomonad. 3. Conversion of D-fuconate to 2-keto-3-deoxy-D-fuconate by a dehydratase. J. Biol. Chem. 247 (1972) 2233-2237. [PMID: 4335868]

[EC 4.2.1.67 created 1976]

EC 4.2.1.68

Accepted name: L-fuconate dehydratase

Reaction: L-fuconate = 2-dehydro-3-deoxy-L-fuconate + H2O

Other name(s): L-fuconate hydro-lyase

Systematic name: L-fuconate hydro-lyase (2-dehydro-3-deoxy-L-fuconate-forming)

Comments: Also acts, slowly, on D-arabinonate.

Links to other databases: BRENDA, EXPASY, KEGG, Metacyc, PDB, CAS registry number: 37292-84-5

References:

1. Yuen, R. and Schachter, H. L-Fucose metabolism in mammals. I. Pork liver L-fuconate hydro-lyase. Can. J. Biochem. 50 (1972) 798-806. [PMID: 5050937]

[EC 4.2.1.68 created 1976]

EC 4.2.1.69

Accepted name: cyanamide hydratase

Reaction: urea = cyanamide + H2O

Other name(s): urea hydro-lyase

Systematic name: urea hydro-lyase (cyanamide-forming)

Links to other databases: BRENDA, EXPASY, KEGG, Metacyc, UM-BBD, CAS registry number: 50812-20-9

References:

1. Stransky, H. and Amberger, A. Isolation and properties of a cyanamide hydratase (EC 4.2.1) from Myrothecium verrucaria. Z. Pflanzenphysiol. 70 (1973) 74-87.

[EC 4.2.1.69 created 1976]

EC 4.2.1.70

Accepted name: pseudouridylate synthase

Reaction: uracil + D-ribose 5-phosphate = pseudouridine 5'-phosphate + H2O

Other name(s): pseudouridylic acid synthetase; pseudouridine monophosphate synthetase; 5-ribosyluracil 5-phosphate synthetase; pseudouridylate synthetase; upsilonUMP synthetase; uracil hydro-lyase (adding D-ribose 5-phosphate); YeiN; pseudouridine-5'-phosphate glycosidase

Systematic name: uracil hydro-lyase (adding D-ribose 5-phosphate; pseudouridine-5'-phosphate-forming)

Comments: The reaction it readily reversible. While the enzymes from Tetrahymena pyriformis and Agrobacterium tumefaciens produce pseudouridine 5'-phosphate the enzyme from Escherichia coli functions as a pseudouridine-5'-phosphate glycosidase in vivo [5].

Links to other databases: BRENDA, EXPASY, KEGG, Metacyc, PDB, CAS registry number: 9023-35-2

References:

1. Heinrikson, R.L. and Goldwasser, E. Studies on the biosynthesis of 5-ribosyluracil 5'-monophosphate in Tetrahymena pyriformis. J. Biol. Chem. 239 (1964) 1177-1187. [PMID: 14165924]

2. Matsushita, T. and Davis, F.F. Studies on pseudouridylic acid synthetase from various sources. Biochim. Biophys. Acta 238 (1971) 165-173. [PMID: 4936431]

3. Rensen, J.F., Matsushita, T., Chirikjian, J.G. and Davis, F.F. Enzymatic synthesis of deoxypseudouridylic acid and a study of certain of its properties. Biochim. Biophys. Acta 281 (1972) 481-487. [PMID: 4569284]

4. Suzuki, T. and Hochater, R.M. On the biosynthesis of pseudouridine and of pseudouridylic acid in Agrobacterium tumefaciens. Can. J. Biochem. 44 (1966) 259-272. [PMID: 5942965]

5. Preumont, A., Snoussi, K., Stroobant, V., Collet, J.F. and Van Schaftingen, E. Molecular identification of pseudouridine-metabolizing enzymes. J. Biol. Chem. 283 (2008) 25238-25246. [PMID: 18591240]

[EC 4.2.1.70 created 1978]

[EC 4.2.1.71 Deleted entry: acetylenecarboxylate hydratase. This enzyme is identical to EC 4.2.1.27, acetylenecarboxylate hydratase (EC 4.2.1.71 created 1978, modified 1989, modified 2000, deleted 2004)]

[EC 4.2.1.72 Transferred entry: acetylenedicarboxylate hydratase. Now EC 4.1.1.78, acetylenedicarboxylate decarboxylase (EC 4.2.1.72 created 1978, deleted 2000)]

EC 4.2.1.73

Accepted name: protoaphin-aglucone dehydratase (cyclizing)

Reaction: protoaphin aglucone = xanthoaphin + H2O

Other name(s): protoaphin dehydratase; protoaphin dehydratase (cyclizing); protoaphin-aglucone hydro-lyase (cyclizing)

Systematic name: protoaphin-aglucone hydro-lyase (cyclizing; xanthoaphin-forming)

Comments: The product is converted non-enzymically to erythroaphin, an aphid pigment.

Links to other databases: BRENDA, EXPASY, KEGG, Metacyc, CAS registry number: 64177-87-3

References:

1. Cameron, D.W., Sawyer, W.H. and Trikojus, V.M. Colouring matters of the Aphidoidea. XLII. Purification and properties of the cyclising enzyme [Protoaphin dehydratase (cyclising)] concerned with pigment transformation in the wooly aphid Eriosoma lanigerum Hausmann (Hemiptera: Insecta). Aust. J. Biol. Sci. 30 (1977) 173-181.

[EC 4.2.1.73 created 1978]

EC 4.2.1.74

Accepted name: long-chain-enoyl-CoA hydratase

Reaction: a long-chain (3S)-3-hydroxyacyl-CoA = a long-chain trans-2-enoyl-CoA + H2O

Glossary: a long-chain acyl-CoA = an acyl-CoA thioester where the acyl chain contains 13 to 22 carbon atoms.

Other name(s): long-chain enoyl coenzyme A hydratase

Systematic name: long-chain-(3S)-3-hydroxyacyl-CoA hydro-lyase

Comments: Acts in the reverse direction. The best substrate is oct-3-enoyl-CoA. Unlike EC 4.2.1.17 enoyl-CoA hydratase, it does not act on crotonoyl-CoA.

Links to other databases: BRENDA, EXPASY, KEGG, Metacyc, CAS registry number: 62009-81-8

References:

1. Fong, J.C. and Schulz, H. Purification and properties of pig heart crotonase and the presence of short chain and long chain enoyl coenzyme A hydratases in pig and guinea pig tissues. J. Biol. Chem. 252 (1977) 542-547. [PMID: 833142]

2. Schulz, H. Long chain enoyl coenzyme A hydratase from pig heart. J. Biol. Chem. 249 (1974) 2704-2709. [PMID: 4828315]

[EC 4.2.1.74 created 1981]

EC 4.2.1.75

Accepted name: uroporphyrinogen-III synthase

Reaction: hydroxymethylbilane = uroporphyrinogen III + H2O

For diagram of reaction click here (mechanism).

Other name(s): porphobilinogenase; uroporphyrinogen isomerase; uroporphyrinogen III cosynthase; URO-synthase; hydroxymethylbilane hydro-lyase (cyclizing)

Systematic name: hydroxymethylbilane hydro-lyase (cyclizing; uroporphyrinogen-III-forming)

Comments: In the presence of EC 2.5.1.61, hydroxymethylbilane synthase, the enzyme forms uroporphyrinogen III from porphobilinogen.

Links to other databases: BRENDA, EXPASY, KEGG, Metacyc, PDB, CAS registry number: 37340-55-9

References:

1. Battersby, A.R., Fookes, C.J.R., Matcham, G.W.J. and McDonald, E. Biosynthesis of the pigments of life: formation of the macrocycle. Nature 285 (1980) 17-21. [PMID: 6769048]

2. Tsai, S.-F., Bishop, D.F. and Desnick, R.J. Purification and properties of uroporphyrinogen III synthase from human erythrocytes. J. Biol. Chem. 262 (1987) 1268-1273. [PMID: 3805019]

[EC 4.2.1.75 created 1982]

EC 4.2.1.76

Accepted name: UDP-glucose 4,6-dehydratase

Reaction: UDP-α-D-glucose = UDP-4-dehydro-6-deoxy-α-D-glucose + H2O

For diagram of reaction click here.

Other name(s): UDP-D-glucose-4,6-hydrolyase; UDP-D-glucose oxidoreductase; UDP-glucose 4,6-hydro-lyase

Systematic name: UDP-α-D-glucose 4,6-hydro-lyase (UDP-4-dehydro-6-deoxy-α-D-glucose-forming)

Links to other databases: BRENDA, EXPASY, KEGG, Metacyc, CAS registry number: 68189-53-7

References:

1. Kamsteeg, J., van Brederode, J. and van Nigtevecht, G. The formation of UDP-L-rhamnose from UDP-D-glucose by an enzyme preparation of red campion (Silene dioica (L) Clairv) leaves. FEBS Lett. 91 (1978) 281-284. [PMID: 680134]

[EC 4.2.1.76 created 1984]

EC 4.2.1.77

Accepted name: trans-L-3-hydroxyproline dehydratase

Reaction: trans-L-3-hydroxyproline = Δ1-pyrroline 2-carboxylate + H2O

Other name(s): trans-L-3-hydroxyproline hydro-lyase

Systematic name: trans-L-3-hydroxyproline hydro-lyase (Δ1-pyrroline-2-carboxylate-forming)

Comments: Highly specific. 2,3-Dehydroproline is an intermediate.

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

References:

1. Ramaswamy, S.G. Conversion of 3-hydroxyproline to proline in the rat requires reduced pyridine-nucleotides. Fed. Proc. 42 (1983) 2232 only.

[EC 4.2.1.77 created 1984]

EC 4.2.1.78

Accepted name: (S)-norcoclaurine synthase

Reaction: 4-hydroxyphenylacetaldehyde + dopamine = (S)-norcoclaurine + H2O

For diagram click here.

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

Other name(s): (S)-norlaudanosoline synthase; 4-hydroxyphenylacetaldehyde hydro-lyase (adding dopamine)

Systematic name: 4-hydroxyphenylacetaldehyde hydro-lyase [adding dopamine; (S)-norcoclaurine-forming]

Comments: The reaction makes a six-membered ring by forming a bond between C-6 of the 3,4-dihydroxyphenyl group of the dopamine and C-1 of the aldehyde in the imine formed between the substrates. The product is the precursor of the benzylisoquinoline alkaloids in plants. The enzyme, formerly known as (S)-norlaudanosoline synthase, will also catalyse the reaction of 4-(2-aminoethyl)benzene-1,2-diol + (3,4-dihydroxyphenyl)acetaldehyde to form (S)-norlaudanosoline, but this alkaloid has not been found to occur in plants.

Links to other databases: BRENDA, EXPASY, KEGG, Metacyc, PDB, CAS registry number: 79122-01-3

References:

1. Stadler, R., Zenk, M.H. A revision of the generally accepted pathway for the biosynthesis of the benzyltetrahydroisoquinoline reticuline. Liebigs Ann. Chem. (1990) 555-562.

2. Stadler, R., Kutchan, T.M., Zenk, M.H. (S)-Norcoclaurine is the central intermediate in benzylisoquinoline alkaloid biosynthesis. Phytochemistry 28 (1989) 1083-1086.

3. Samanani, N. and Facchini, P.J. Purification and characterization of norcoclaurine synthase. The first committed enzyme in benzylisoquinoline alkaloid biosynthesis in plants. J. Biol. Chem. 277 (2002) 33878-33883. [PMID: 12107162]

[EC 4.2.1.78 created 1984, modified 1999]

EC 4.2.1.79

Accepted name: 2-methylcitrate dehydratase

Reaction: (2S,3S)-2-hydroxybutane-1,2,3-tricarboxylate = (Z)-but-2-ene-1,2,3-tricarboxylate + H2O

Glossary: (2S,3S)-2-methylcitrate = (2S,3S)-2-hydroxybutane-1,2,3-tricarboxylate
cis-2-methylaconitate = (Z)-but-2-ene-1,2,3-tricarboxylate

Other name(s): 2-methylcitrate hydro-lyase; PrpD; 2-hydroxybutane-1,2,3-tricarboxylate hydro-lyase

Systematic name: (2S,3S)-2-hydroxybutane-1,2,3-tricarboxylate hydro-lyase [(Z)-but-2-ene-1,2,3-tricarboxylate-forming]

Comments: The enzyme is specific for (2S,3S)-methylcitrate, showing no activity with (2R,3S)-methylcitrate [2]. The enzyme can also use cis-aconitate as a substrate but more slowly [2]. Both this enzyme and EC 4.2.1.3, aconitate hydratase, are required to complete the isomerization of (2S,3S)-methylcitrate to (2R,3S)-2-methylisocitrate [2].

Links to other databases: BRENDA, EXPASY, KEGG, Metacyc, PDB, CAS registry number: 80891-26-5

References:

1. Aoki, H. and Tabuchi, T. Purification and properties of 2-methylcitrate dehydratase from Yarrowia lipolytica. Agric. Biol. Chem. 45 (1981) 2831-2837.

2. Brock, M., Maerker, C., Schütz, A., Völker, U. and Buckel, W. Oxidation of propionate to pyruvate in Escherichia coli. Involvement of methylcitrate dehydratase and aconitase. Eur. J. Biochem. 269 (2002) 6184-6194. [PMID: 12473114]

[EC 4.2.1.79 created 1984, modified 2007]

EC 4.2.1.80

Accepted name: 2-oxopent-4-enoate hydratase

Reaction: 4-hydroxy-2-oxopentanoate = 2-oxopent-4-enoate + H2O

For diagram of reaction click here and another click here and another.

Other name(s): 2-keto-4-pentenoate hydratase; OEH; 2-keto-4-pentenoate (vinylpyruvate) hydratase; 4-hydroxy-2-oxopentanoate hydro-lyase

Systematic name: 4-hydroxy-2-oxopentanoate hydro-lyase (2-oxopent-4-enoate-forming)

Comments: Also acts, more slowly, on cis-2-oxohex-4-enoate, but not on the trans-isomer.

Links to other databases: BRENDA, EXPASY, KEGG, Metacyc, PDB, UM-BBD, CAS registry number: 64427-80-1

References:

1. Kunz, D.A., Ribbons, D.W. and Chapman, P.J. Metabolism of allylglycine and cis-crotylglycine by Pseudomonas putida (arvilla) mt-2 harboring a TOL plasmid. J. Bacteriol. 148 (1981) 72-82. [PMID: 7287632]

[EC 4.2.1.80 created 1984]

EC 4.2.1.81

Accepted name: D(–)-tartrate dehydratase

Reaction: (S,S)-tartrate = oxaloacetate + H2O

Other name(s): D-tartrate dehydratase; (S,S)-tartrate hydro-lyase

Systematic name: (S,S)-tartrate hydro-lyase (oxaloacetate-forming)

Comments: Requires Fe2+ or Mn2+. cf. EC 4.2.1.32 L(+)-tartrate dehydratase.

Links to other databases: BRENDA, EXPASY, KEGG, Metacyc, CAS registry number: 82532-88-5

References:

1. Rode, H. and Giffhorn, F. D-(–)-Tartrate dehydratase of Rhodopseudomonas sphaeroides: purification, characterization, and application to enzymatic determination of D-(–)-tartrate.J. Bacteriol. 150 (1982) 1061-1068. [PMID: 6978882]

2. Rode, H. and Giffhorn, F. Ferrous- or cobalt ion-dependent D-(–)-tartrate dehydratase of pseudomonads: purification and properties. J. Bacteriol. 151 (1982) 1602-1604. [PMID: 7107563]

[EC 4.2.1.81 created 1986]

EC 4.2.1.82

Accepted name: xylonate dehydratase

Reaction: D-xylonate = 2-dehydro-3-deoxy-D-arabinonate + H2O

Glossary: 2-dehydro-3-deoxy-D-arabinonate = 2-dehydro-3-deoxy-D-xylonate = 3-deoxy-L-glycero-pent-2-ulonate

Other name(s): D-xylo-aldonate dehydratase; D-xylonate dehydratase; D-xylonate hydro-lyase

Systematic name: D-xylonate hydro-lyase (2-dehydro-3-deoxy-D-arabinonate-forming)

Links to other databases: BRENDA, EXPASY, KEGG, Metacyc, CAS registry number: 84788-77-2

References:

1. Dahms, A.S. and Donald, A. D-xylo-Aldonate dehydratase. Methods Enzymol. 90 (1982) 302-305. [PMID: 7154961]

2. Donald, A. Sibley, D., Lyons, D.E. and Dahms, A.S. D-Galactonate dehydrase. Purification and properties. J. Biol. Chem. 254 (1979) 2132-2137. [PMID: 422572]

[EC 4.2.1.82 created 1986]

EC 4.2.1.83

Accepted name: 4-oxalomesaconate hydratase

Reaction: 2-hydroxy-4-oxobutane-1,2,4-tricarboxylate = (1E,3E)-4-hydroxybuta-1,3-diene-1,2,4-tricarboxylate + H2O

For diagram of reaction click here.

Other name(s): 4-carboxy-2-oxohexenedioate hydratase; 4-carboxy-2-oxobutane-1,2,4-tricarboxylate 2,3-hydro-lyase; oxalmesaconate hydratase; γ-oxalmesaconate hydratase; 2-hydroxy-4-oxobutane-1,2,4-tricarboxylate 2,3-hydro-lyase; LigJ; GalB; 4-oxalmesaconate hydratase

Systematic name: (1E,3E)-4-hydroxybuta-1,3-diene-1,2,4-tricarboxylate 1,2-hydro-lyase (2-hydroxy-4-oxobutane-1,2,4-tricarboxylate-forming)

Comments: This enzyme participates in the degradation of protocatechuate (via the meta-cleavage pathway), syringate and gallate, catalysing the reaction in the opposite direction [1-3]. It accepts the enol-form of 4-oxalomesaconate, 2-hydroxy-4-carboxy-hexa-2,4-dienedioate [4].

Links to other databases: BRENDA, EXPASY, KEGG, Metacyc, CAS registry number: 85204-95-1

References:

1. Maruyama, K. Enzymes responsible for degradation of 4-oxalmesaconic acid in Pseudomonas ochraceae. J. Biochem. 93 (1983) 567-574. [PMID: 6841354]

2. Maruyama, K. Purification and properties of γ-oxalomesaconate hydratase from Pseudomonas ochraceae grown with phthalate. Biochem. Biophys. Res. Commun. 128 (1985) 271-277. [PMID: 3985968]

3. Hara, H., Masai, E., Katayama, Y. and Fukuda, M. The 4-oxalomesaconate hydratase gene, involved in the protocatechuate 4,5-cleavage pathway, is essential to vanillate and syringate degradation in Sphingomonas paucimobilis SYK-6. J. Bacteriol. 182 (2000) 6950-6957. [PMID: 11092855]

4. Nogales, J., Canales, A., Jimenez-Barbero, J., Serra, B., Pingarron, J.M., Garcia, J.L. and Diaz, E. Unravelling the gallic acid degradation pathway in bacteria: the gal cluster from Pseudomonas putida. Mol. Microbiol. 79 (2011) 359-374. [PMID: 21219457]

[EC 4.2.1.83 created 1986, modified 2011]

EC 4.2.1.84

Accepted name: nitrile hydratase

Reaction: An aliphatic amide = a nitrile + H2O

Other name(s): nitrilase; 3-cyanopyridine hydratase; NHase; L-NHase; H-NHase; acrylonitrile hydratase; aliphatic nitrile hydratase

Systematic name: aliphatic-amide hydro-lyase (nitrile-forming)

Comments: Acts on short-chain aliphatic nitriles, converting them into the corresponding acid amides. Does not act on these amides or on aromatic nitriles. cf. EC 3.5.5.1 nitrilase.

Links to other databases: BRENDA, EXPASY, KEGG, UM-BBD, Metacyc, PDB, UM-BBD, CAS registry number: 82391-37-5

References:

1. Asano, Y., Fujishiro, K., Tani, Y. and Yamada, H. Microbial degradation of nitrile compounds. 5. Aliphatic nitrile hydratase from Arthrobacter sp J-1. Purification and characterization. Agric. Biol. Chem. 46 (1982) 1165-1174.

[EC 4.2.1.84 created 1989]

EC 4.2.1.85

Accepted name: dimethylmaleate hydratase

Reaction: (2R,3S)-2,3-dimethylmalate = dimethylmaleate + H2O

For diagram click here.

Other name(s): (2R,3S)-2,3-dimethylmalate hydro-lyase

Systematic name: (2R,3S)-2,3-dimethylmalate hydro-lyase (dimethylmaleate-forming)

Comments: Requires Fe2+. Inhibited by oxygen.

Links to other databases: BRENDA, EXPASY, GTD, KEGG, Metacyc, CAS registry number: 93229-56-2

References:

1. Kollmann-Koch, A. and Eggerer, H. Nicotinic acid metabolism. Dimethylmaleate hydratase. Hoppe-Seyler's Z. Physiol. Chem. 365 (1984) 847-857. [PMID: 6489933]

[EC 4.2.1.85 created 1989]

[EC 4.2.1.86 Deleted entry: 16-dehydroprogesterone hydratase (reaction is identical to that of EC 4.2.1.98, 16α-hydroxyprogesterone dehydratase) (EC 4.2.1.86 created 1989, deleted 2004)]

EC 4.2.1.87

Accepted name: octopamine dehydratase

Reaction: 1-(4-hydroxyphenyl)-2-aminoethanol = (4-hydroxyphenyl)acetaldehyde + NH3

Other name(s): octopamine hydrolyase; octopamine hydro-lyase (deaminating)

Systematic name: 1-(4-hydroxyphenyl)-2-aminoethanol hydro-lyase [deaminating; (4-hydroxyphenyl)acetaldehyde-forming]

Comments: The enzyme-catalysed reaction is believed to be dehydration to an enamine, which is spontaneously hydrolysed to an aldehyde and ammonia.

Links to other databases: BRENDA, EXPASY, KEGG, Metacyc, CAS registry number: 109456-55-5

References:

1. Cuskey, S.M., Peccoraro, V. and Olsen, R.H. Initial catabolism of aromatic biogenic amines by Pseudomonas aeruginosa PAO: pathway description, mapping of mutations, and cloning of essential genes. J. Bacteriol. 169 (1987) 2398-2404. [PMID: 3034855]

[EC 4.2.1.87 created 1989]

EC 4.2.1.88

Accepted name: synephrine dehydratase

Reaction: (R)-synephrine = (4-hydroxyphenyl)acetaldehyde + methylamine

Glossary: (R)-synephrine = D-(–)-synephrine = 4-[(1R)-1-hydroxy-2-(methylamino)ethyl]phenol

Other name(s): syringinase

Systematic name: (R)-synephrine hydro-lyase (methylamine-forming)

Comments: Removal of H2O from (R)-synephrine produces a 2,3-enamine, which hydrolyses to the products shown in the reaction above. The enzyme from Arthrobacter synephrinum is highly specific [1].

Links to other databases: BRENDA, EXPASY, KEGG, Metacyc, CAS registry number: 104118-54-9

References:

1. Veeraswamy, M., Devi, N.A., Krishnan Kutty, R. and Subba Rao, P.V. Conversion of (±) synephrine into p-hydroxyphenylacetaldehyde by Arthrobacter synephrinum. A novel enzymic reaction. Biochem. J. 159 (1976) 807-809. [PMID: 1008837]

2. Manne, V., Kutty, K.R. and Pillarisetti, S.R. Purification and properties of synephrinase from Arthrobacter synephrinum. Arch. Biochem. Biophys. 248 (1986) 324-334. [PMID: 3729420]

[EC 4.2.1.88 created 1989, modified 2012]

[EC 4.2.1.89 Deleted entry: carnitine dehydratase. The activity has now been shown to be due to EC 2.8.3.21, L-carnitine CoA-transferase and EC 4.2.1.149, crotonobetainyl-CoA hydratase. (EC 4.2.1.89 created 1989, deleted 2013)]

EC 4.2.1.90

Accepted name: L-rhamnonate dehydratase

Reaction: L-rhamnonate = 2-dehydro-3-deoxy-L-rhamnonate + H2O

For diagram of reaction click here.

Other name(s): L-rhamnonate hydro-lyase

Systematic name: L-rhamnonate hydro-lyase (2-dehydro-3-deoxy-L-rhamnonate-forming)

Links to other databases: BRENDA, EXPASY, KEGG, Metacyc, PDB, CAS registry number: 99533-47-8

References:

1. Rigo, L.U., Maréchal, L.R., Vieira, M.M. and Veiga, L.A. Oxidative pathway for L-rhamnose degradation in Pullularia pullulans. Can. J. Microbiol. 31 (1985) 817-822.

[EC 4.2.1.90 created 1989]

EC 4.2.1.91

Accepted name: arogenate dehydratase

Reaction: L-arogenate = L-phenylalanine + H2O + CO2

For diagram click here.

Other name(s): carboxycyclohexadienyl dehydratase; L-arogenate hydro-lyase (decarboxylating)

Systematic name: L-arogenate hydro-lyase (decarboxylating; L-phenylalanine-forming)

Comments: Also acts on prephenate and D-prephenyllactate. cf. EC 4.2.1.51, prephenate dehydratase.

Links to other databases: BRENDA, EXPASY, KEGG, Metacyc, PDB, CAS registry number: 76600-70-9

References:

1. Fischer, R. and Jensen, R. Arogenate dehydratase. Methods Enzymol. 142 (1987) 495-502. [PMID: 3600377]

2. Zamir, L.O., Tiberio, R., Devor, K.A., Sauriol, F., Ahmad, S. and Jensen, R.A. Structure of D-prephenyllactate. A carboxycyclohexadienyl metabolite from Neurospora crassa. J. Biol. Chem. 263 (1988) 17284-17290. [PMID: 2972718]

3. Siehl, D.L. and Conn, E.E. Kinetic and regulatory properties of arogenate dehydratase in seedlings of Sorghum bicolor (L.) Moench. Arch. Biochem. Biophys. 260 (1988) 822-829. [PMID: 3124763]

[EC 4.2.1.91 created 1992, modified 2005]

EC 4.2.1.92

Accepted name: hydroperoxide dehydratase

Reaction: (9Z,11E,15Z)-(13S)-hydroperoxyoctadeca-9,11,15-trienoate = (9Z,15Z)-(13S)-12,13-epoxyoctadeca-9,11,15-trienoate + H2O

Glossary: 13-hydroperoxylinolenoate = (9Z,11E,15Z)-(13S)-hydroperoxyoctadeca-9,11,15-trienoate

Other name(s): hydroperoxide isomerase; linoleate hydroperoxide isomerase; linoleic acid hydroperoxide isomerase; HPI; (9Z,11E,14Z)-(13S)-hydroperoxyoctadeca-9,11,14-trienoate 12,13-hydro-lyase; (9Z,11E,14Z)-(13S)-hydroperoxyoctadeca-9,11,14-trienoate 12,13-hydro-lyase [(9Z)-(13S)-12,13-epoxyoctadeca-9,11-dienoate-forming]; allene oxide synthase; AOS

Systematic name: (9Z,11E,15Z)-(13S)-hydroperoxyoctadeca-9,11,15-trienoate 12,13-hydro-lyase [(9Z,15Z)-(13S)-12,13-epoxyoctadeca-9,11,15-trienoate-forming]

Comments: Acts on a number of unsaturated fatty-acid hydroperoxides, forming the corresponding allene oxides. The product of the above reaction is unstable and is acted upon by EC 5.3.99.6, allene-oxide cyclase, to form the cyclopentenone derivative (15Z)-12-oxophyto-10,15-dienoate (OPDA), which is the first cyclic and biologically active metabolite in the jasmonate biosynthesis pathway [3]. The enzyme from many plants belongs to the CYP-74 family of P450 monooxygenases [4].

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

References:

1. Esselman, W.J. and Clagett, C.O. Products of linoleic hydroperoxide-decomposing enzyme of alfalfa seed. J. Lipid Res. 15 (1974) 173-178. [PMID: 4208994]

2. Hamberg, M. Mechanism of corn hydroperoxide isomerase - detection of 12,13(S)-oxido-9(Z),11-octadecadienoic acid. Biochim. Biophys. Acta 920 (1987) 76-84.

3. Hamberg, M. Biosynthesis of 12-oxo-10,15(Z)-phytodienoic acid: identification of an allene oxide cyclase. Biochem. Biophys. Res. Commun. 156 (1988) 543-550. [PMID: 3178850]

4. Laudert, D., Pfannschmidt, U., Lottspeich, F., Holländer-Czytko, H. and Weiler, E.W. Cloning, molecular and functional characterization of Arabidopsis thaliana allene oxide synthase (CYP 74), the first enzyme of the octadecanoid pathway to jasmonates. Plant Mol. Biol. 31 (1996) 323-335. [PMID: 8756596]

[EC 4.2.1.92 created 1992, modified 2008]

EC 4.2.1.93

Accepted name: ATP-dependent NAD(P)H-hydrate dehydratase

Reaction: (1) ATP + (6S)-6β-hydroxy-1,4,5,6-tetrahydronicotinamide-adenine dinucleotide = ADP + phosphate + NADH
(2) ATP + (6S)-6β-hydroxy-1,4,5,6-tetrahydronicotinamide-adenine dinucleotide phosphate = ADP + phosphate + NADPH

For diagram of reaction click here

Glossary: (6S)-6β-hydroxy-1,4,5,6-tetrahydronicotinamide-adenine dinucleotide = (S)-NADH-hydrate = (S)-NADHX
(6S)-6β-hydroxy-1,4,5,6-tetrahydronicotinamide-adenine dinucleotide phosphate = (S)-NADPH-hydrate = (S)-NADPHX

Other name(s): reduced nicotinamide adenine dinucleotide hydrate dehydratase; ATP-dependent H4NAD(P)+OH dehydratase; (6S)-β-6-hydroxy-1,4,5,6-tetrahydronicotinamide-adenine-dinucleotide hydro-lyase(ATP-hydrolysing); (6S)-6-β-hydroxy-1,4,5,6-tetrahydronicotinamide-adenine-dinucleotide hydro-lyase (ATP-hydrolysing; NADH-forming)

Systematic name: (6S)-6β-hydroxy-1,4,5,6-tetrahydronicotinamide-adenine-dinucleotide hydro-lyase (ATP-hydrolysing; NADH-forming)

Comments: Acts equally well on hydrated NADH and hydrated NADPH. NAD(P)H spontaneously hydrates to both the (6S)- and (6R)- isomers, and these are interconverted by EC 5.1.99.6, NAD(P)H-hydrate epimerase, to a 60:40 ratio [4]. Hence EC 4.2.1.93 together with EC 5.1.99.6 can restore the mixture of hydrates into NAD(P)H [3,4]. The enzyme from eukaryotes has no activity with ADP, contrary to the enzyme from bacteria (cf. EC 4.2.1.136, ADP-dependent NAD(P)H-hydrate dehydratase) [4].

Links to other databases: BRENDA, EXPASY, KEGG, Metacyc, CAS registry number: 116669-08-0

References:

1. Meinhart, J.O., Chaykin, S. and Krebs, E.G. Enzymatic conversion of a reduced diphosphopyridine nucleotide derivative to reduced diphosphopyridine nucleotide. J. Biol. Chem. 220 (1956) 821-829. [PMID: 13331940]

2. Regueiro Varela, B., Amelunxen, R. and Grisolia, S. Synthesis and degradation of monohydroxytetrahydronicotinamide adenine dinucleotide phosphate. Physiol. Chem. Phys. 2 (1970) 445-454.

3. Acheson, S.A., Kirkman, H.N. and Wolfenden, R. Equilibrium of 5,6-hydration of NADH and mechanism of ATP-dependent dehydration. Biochemistry 27 (1988) 7371-7375. [PMID: 3061454]

4. 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]

[EC 4.2.1.93 created 1992, modified 2012]

EC 4.2.1.94

Accepted name: scytalone dehydratase

Reaction: scytalone = 1,3,8-trihydroxynaphthalene + H2O

Other name(s): scytalone 7,8-hydro-lyase

Systematic name: scytalone 7,8-hydro-lyase (1,3,8-trihydroxynaphthalene-forming)

Comments: Involved, with EC 1.1.1.252 tetrahydroxynaphthalene reductase, in the biosynthesis of melanin in pathogenic fungi.

Links to other databases: BRENDA, EXPASY, KEGG, Metacyc, PDB, CAS registry number: 118901-79-4

References:

1. Butler, M.J., Lazarovits, G., Higgins, V.J. and Lachance, M.-A. Partial-purification and characterization of a dehydratase associated with the pentaketide melanogenesis pathway of Phaeococcomyces sp and other fungi. Exp. Mycol. 12 (1988) 367-376.

2. Tajima, S., Kubo, Y., Furusawa, I. and Shishiyama, J. Purification of a melanin biosynthetic enzyme converting scytalone to 1,3,8-trihydroxynaphthalene from Cochliobolus miyabeanus. Exp. Mycol. 13 (1989) 69.

3. Wheeler, M.H. and Greenblatt, G.A. The inhibition of melanin biosynthetic reactions in Pyricularia oryzae by compounds that prevent rice blast disease. Exp. Mycol. 12 (1988) 151-160.

[EC 4.2.1.94 created 1992]

EC 4.2.1.95

Accepted name: kievitone hydratase

Reaction: kievitone hydrate = kievitone + H2O

Other name(s): KHase; kievitone-hydrate hydro-lyase

Systematic name: kievitone-hydrate hydro-lyase (kievitone-forming)

Comments: The enzyme from Fusarium sp. hydrates the methylbutenyl sidechain of the isoflavonoid phytoalexins, thus reducing their toxicity.

Links to other databases: BRENDA, EXPASY, KEGG, Metacyc, PDB, CAS registry number: 70431-10-6

References:

1. Turbek, C.S., Li, D., Choi, G.H., Schardl, C.L. and Smith, D.A. Induction and purification of kievitone hydratase from Fusarium solani f. sp. phaseoli. Phytochemistry 29 (1990) 2841-2846. [PMID: 1366757]

[EC 4.2.1.95 created 1992]

EC 4.2.1.96

Accepted name: 4a-hydroxytetrahydrobiopterin dehydratase

Reaction: (6R)-6-(L-erythro-1,2-dihydroxypropyl)-5,6,7,8-tetrahydro-4a-hydroxypterin = (6R)-6-(L-erythro-1,2-dihydroxypropyl)-7,8-dihydro-6H-pterin + H2O

For diagram click here.

Glossary: 4a-hydroxytetrahydrobiopterin = (6R)-6-(L-erythro-1,2-dihydroxypropyl)-5,6,7,8-tetrahydro-4a-hydroxypterin

Other name(s): 4α-hydroxy-tetrahydropterin dehydratase; pterin-4α-carbinolamine dehydratase; 4a-hydroxytetrahydrobiopterin hydro-lyase

Systematic name: (6R)-6-(L-erythro-1,2-dihydroxypropyl)-5,6,7,8-tetrahydro-4a-hydroxypterin hydro-lyase [(6R)-6-(L-erythro-1,2-dihydroxypropyl)-7,8-dihydro-6H-pterin-forming]

Comments: Catalyses the dehydration of 4a-hydroxytetrahydrobiopterins

Links to other databases: BRENDA, EXPASY, KEGG, Metacyc, PDB, CAS registry number: 87683-70-3

References:

1. Hauer, C.R., Rebrin, I., Thöny, B., Neuheiser, F., Curtius, H.C., Hunziker, P., Blau, N., Ghisla, S., Heizmann, C.W. Phenylalanine hydroxylase-stimulating protein: pterin-4α-carbinolamine dehydratase from rat and human liver. J. Biol. Chem. 268 (1993) 4828-4831. [PMID: 8444860]

[EC 4.2.1.96 created 1999]

EC 4.2.1.97

Accepted name: phaseollidin hydratase

Reaction: phaseollidin hydrate = phaseollidin + H2O

Other name(s): phaseollidin-hydrate hydro-lyase

Systematic name: phaseollidin-hydrate hydro-lyase (phaseollidin-forming)

Comments: the enzyme from Fusarium solani, which is distinct from kievitone hydratase (EC 4.2.1.95), hydrates the methylbutenyl side-chain of the isoflavonoid phytoalexin, phaseollidin.

Links to other databases: BRENDA, EXPASY, KEGG, Metacyc, CAS registry number: 143597-34-6

References:

1. Turbek, C.S., Smith, D.A., Schardl, C.L. An extracellular enzyme from Fusarium solani f.sp. phaseoli, which catalyses hydration of the isoflavonoid phytoalexin, phaseollidin. FEMS Microbiol. Lett. 94 (1992) 187-190. [PMID: 1521768]

[EC 4.2.1.97 created 1999]

EC 4.2.1.98

Accepted name: 16α-hydroxyprogesterone dehydratase

Reaction: 16α-hydroxyprogesterone = 16,17-didehydroprogesterone + H2O

For diagram click here.

Other name(s): hydroxyprogesterone dehydroxylase; 16α-hydroxyprogesterone dehydroxylase; 16α-dehydroxylase; 16α-hydroxyprogesterone hydro-lyase

Systematic name: 16α-hydroxyprogesterone hydro-lyase (16,17-didehydroprogesterone-forming)

Comments: 16α-Hydroxypregnenolone is also a substrate.

Links to other databases: BRENDA, EXPASY, KEGG, Metacyc, CAS registry number: 89287-36-5

References:

1. Glass, T.L. and Lamppa, R.S. Purification and properties of 16α-hydroxyprogesterone dehydroxylase from Eubacterium sp. strain 144. Biochim. Biophys. Acta 837 (1985) 103-110. [PMID: 4052439]

[EC 4.2.1.98 created 1999, modified 2004 (EC 4.2.1.86 created 1989, incorporated 2004)]

EC 4.2.1.99

Accepted name: 2-methylisocitrate dehydratase

Reaction: (2S,3R)-3-hydroxybutane-1,2,3-tricarboxylate = (Z)-but-2-ene-1,2,3-tricarboxylate + H2O

Glossary: cis-2-methylaconitate = (Z)-but-2-ene-1,2,3-tricarboxylate
(2S,3R)-2-methylisocitrate = (2S,3R)-3-hydroxybutane-1,2,3-tricarboxylate = threo-Ds-2-methylisocitrate

Other name(s): (2S,3R)-3-hydroxybutane-1,2,3-tricarboxylate hydro-lyase

Systematic name: (2S,3R)-3-hydroxybutane-1,2,3-tricarboxylate hydro-lyase [(Z)-but-2-ene-1,2,3-tricarboxylate-forming]

Comments: The enzyme from the fungus Yarrowia lipolytica (Saccharomycopsis) does not act on isocitrate.

Links to other databases: BRENDA, EXPASY, KEGG, Metacyc, PDB, CAS registry number: 170780-51-5

References:

1. Aoki, H., Uchiyama, H., Umetsu, H., Tabuchi, T. Isolation of 2-methylisocitrate dehydratase, a new enzyme serving in the methylcitric acid cycle for propionate metabolism, from Yarrowia lipolytica. Biosci. Biotechnol. Biochem. 59 (1995) 1825-1828

2. Tabuchi, T., Umetsu, H., Aoki, H., Uchiyama, H. Characteristics of 2-methylisocitrate dehydratase, isolated from Yarrowia lipolytica, in comparison to aconitase. Biosci. Biotechnol. Biochem. 59 (1995) 2013-2017.

[EC 4.2.1.99 created 1999]

EC 4.2.1.100

Accepted name: cyclohexa-1,5-dienecarbonyl-CoA hydratase

Reaction: 6-hydroxycyclohex-1-ene-1-carbonyl-CoA = cyclohexa-1,5-diene-1-carbonyl-CoA + H2O

For diagram of reaction click here.

Other name(s): cyclohexa-1,5-diene-1-carbonyl-CoA hydratase; dienoyl-CoA hydratase; cyclohexa-1,5-dienecarbonyl-CoA hydro-lyase (incorrect)

Systematic name: 6-hydroxycyclohex-1-ene-1-carbonyl-CoA hydro-lyase (cyclohexa-1,5-diene-1-carbonyl-CoA-forming)

Comments: Forms part of the anaerobic benzoate degradation pathway, which also includes EC 1.3.8.6 (glutaryl-CoA dehydrogenase), EC 1.3.7.8 (benzoyl-CoA reductase) and EC 4.2.1.55 (3-hydroyxbutyryl-CoA dehydratase).

Links to other databases: BRENDA, EXPASY, KEGG, Metacyc, UM-BBD, CAS registry number: 214355-79-0

References:

1. Laempe, D., Eisenreich, W., Bacher, A. and Fuchs, G. Cyclohexa-1,5-diene-1-carboxyl-CoA hydratase, an enzyme involved in anaerobic metabolism of benzoyl-CoA in the denitrifying bacterium Thauera aromatica. Eur. J. Biochem. 255 (1998) 618-627. [PMID: 9738901] [Erratum Eur. J. Biochem. 257 (1998) 528 only]

2. Harwood, C.S. and Gibson, J. Shedding light on anaerobic benzene ring degradation: a process unique to prokaryotes? J. Bacteriol. 179 (1997) 301-309. [PMID: 8990279]

3. Koch, J., Eisenreich, W., Bacher, A. and Fuchs, G. Products of enzymatic reduction of benzoyl-CoA, a key reaction in anaerobic aromatic metabolism. Eur. J. Biochem. 211 (1993) 649-661. [PMID: 8436125]

[EC 4.2.1.100 created 2000, modified 2001]


Continued with EC 4.2.1.101 to EC 4.2.1.175
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