|Superclasses:||Reactions Classified By Conversion Type → Simple Reactions → Chemical Reactions|
|Reactions Classified By Substrate → Small-Molecule Reactions|
EC Number: 126.96.36.1990
In Pathway: very long chain fatty acid biosynthesis II
Supersedes EC number: 188.8.131.52
Note that this reaction equation differs from the official Enzyme Commission reaction equation for this EC number, which can be found here .
The reaction direction shown, that is, A + B ↔ C + D versus C + D ↔ A + B, is in accordance with the Enzyme Commission system.
Most BioCyc compounds have been protonated to a reference pH value of 7.3, and some reactions have been computationally balanced for hydrogen by adding free protons. Please see the PGDB Concepts Guide for more information.
Mass balance status: Balanced.
Enzyme Commission Primary Name: very-long-chain 3-oxoacyl-CoA reductase
Enzyme Commission Synonyms: very-long-chain 3-ketoacyl-CoA reductase, very-long-chain β-ketoacyl-CoA reductase, KCR (gene name), IFA38 (gene name)
Standard Gibbs Free Energy (ΔrG'° in kcal/mol): -0.1663208 [Latendresse13]
Enzyme Commission Summary:
The second component of the elongase, a microsomal protein complex responsible for extending palmitoyl-CoA and stearoyl-CoA (and modified forms thereof) to very-long-chain fatty acyl CoAs. The enzyme is active with substrates with chain length of C16 to C34, depending on the species. cf. EC 184.108.40.206, very-long-chain 3-oxoacyl-CoA synthase, EC 220.127.116.11, very-long-chain (3R)-3-hydroxyacyl-[acyl-carrier protein] dehydratase, and EC 18.104.22.168, very-long-chain enoyl-CoA reductase.
Instance reactions of [a very-long-chain (3R)-3-hydroxyacyl-CoA → a very-long-chain trans-2,3-dehydroacyl-CoA + H2O] (22.214.171.124):
i8: (3R)-3-hydroxy-cerotoyl-CoA → trans-cerot-2-enoyl-CoA + H2O (126.96.36.199)
i10: (3R)-3-hydroxy-behenoyl-CoA → trans-docos-2-enoyl-CoA + H2O (188.8.131.52)
Instance reactions of [a 2,3,4-saturated fatty acyl CoA + NADP+ = a trans-2-enoyl-CoA + NADPH + H+] (184.108.40.206):
i1: icosanoyl-CoA + NADP+ ← trans-arachido-2-enoyl-CoA + NADPH + H+ (220.127.116.11)
i3: docosanoyl-CoA + NADP+ ← trans-docos-2-enoyl-CoA + NADPH + H+ (18.104.22.168)
i4: cerotoyl-CoA + NADP+ ← trans-cerot-2-enoyl-CoA + NADPH + H+ (22.214.171.124)
i5: lignoceroyl-CoA + NADP+ ← trans-lignocer-2-enoyl-CoA + NADPH + H+ (126.96.36.199)
i7: a very-long-chain 2,3,4-saturated fatty acyl CoA + NADP+ ← a very-long-chain trans-2,3-dehydroacyl-CoA + NADPH + H+ (188.8.131.52)
Instance reaction of [a (3S)-3-hydroxyacyl-CoA ← a trans-2-enoyl-CoA + H2O] (184.108.40.206):
i9: (3R)-3-hydroxy-lignoceroyl-CoA → trans-lignocer-2-enoyl-CoA + H2O (220.127.116.11)
Instance reactions of [a very-long-chain (3R)-3-hydroxyacyl-CoA + NADP+ ← a very-long-chain oxoacyl-CoA + NADPH + H+] (18.104.22.1680):
i11: (3R)-3-hydroxy-lignoceroyl-CoA + NADP+ ← 3-oxo-lignoceroyl-CoA + NADPH + H+ (22.214.171.1240)
i12: (3R)-3-hydroxy-cerotoyl-CoA + NADP+ ← 3-oxo-cerotoyl-CoA + NADPH + H+ (126.96.36.1990)
i13: (3R)-3-hydroxy-behenoyl-CoA + NADP+ ← 3-oxo-behenoyl-CoA + NADPH + H+ (188.8.131.520)
Beaudoin02: Beaudoin F, Gable K, Sayanova O, Dunn T, Napier JA (2002). "A Saccharomyces cerevisiae gene required for heterologous fatty acid elongase activity encodes a microsomal beta-keto-reductase." J Biol Chem 277(13);11481-8. PMID: 11792704
Beaudoin09: Beaudoin F, Wu X, Li F, Haslam RP, Markham JE, Zheng H, Napier JA, Kunst L (2009). "Functional characterization of the Arabidopsis beta-ketoacyl-coenzyme A reductase candidates of the fatty acid elongase." Plant Physiol 150(3);1174-91. PMID: 19439572
Han02: Han G, Gable K, Kohlwein SD, Beaudoin F, Napier JA, Dunn TM (2002). "The Saccharomyces cerevisiae YBR159w gene encodes the 3-ketoreductase of the microsomal fatty acid elongase." J Biol Chem 277(38);35440-9. PMID: 12087109
Wakil62: Wakil, S, Bressler, R (1962). "Studies on the mechanism of fatty acid synthesis. X. Reduced triphosphopyridine nucleotide-acetoacetyl coenzyme A reductase." J Biol Chem 237;687-93. PMID: 14004466
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