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MetaCyc Reaction:

Superclasses: Reactions Classified By Conversion TypeSimple ReactionsChemical Reactions
Reactions Classified By SubstrateSmall-Molecule Reactions

EC Number:

Enzymes and Genes:

Arabidopsis thaliana col: very-long-chain 3-oxoacyl-CoA reductaseInferred from experiment: KCR1
Saccharomyces cerevisiae: very-long-chain 3-oxoacyl-CoA reductaseInferred from experiment: IFA38

In Pathway: very long chain fatty acid biosynthesis II

Supersedes EC number:

Note that this reaction equation differs from the official Enzyme Commission reaction equation for this EC number, which can be found here .

The direction shown, i.e. which substrates are on the left and right sides, is in accordance with the Enzyme Commission system.

Most BioCyc compounds have been protonated to a reference pH value of 7.3. Please see the PGDB Concepts Guide for more information.

Mass balance status: Balanced.

Direct generic reaction:
a very-long-chain (3R)-3-hydroxyacyl-CoA + NADP+ ← a very-long-chain oxoacyl-CoA + NADPH + H+ (

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): -0.1663208Inferred by computational analysis [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, very-long-chain 3-oxoacyl-CoA synthase, EC, very-long-chain (3R)-3-hydroxyacyl-[acyl-carrier protein] dehydratase, and EC, very-long-chain enoyl-CoA reductase.

Citations: [Wakil62, Beaudoin02, Han02a, Beaudoin09 ]

Gene-Reaction Schematic

Gene-Reaction Schematic

Instance reactions of [a very-long-chain (3R)-3-hydroxyacyl-CoA → a very-long-chain trans-2,3-dehydroacyl-CoA + H2O] (
i9: (3R)-3-hydroxy-lignoceroyl-CoA → trans-lignocer-2-enoyl-CoA + H2O (

i10: (3R)-3-hydroxy-behenoyl-CoA → trans-docos-2-enoyl-CoA + H2O (

i11: (3R)-3-hydroxy-cerotoyl-CoA → trans-cerot-2-enoyl-CoA + H2O (

Instance reactions of [a very-long-chain (3R)-3-hydroxyacyl-CoA + NADP+ ← a very-long-chain oxoacyl-CoA + NADPH + H+] (
i12: (3R)-3-hydroxy-lignoceroyl-CoA + NADP+ ← 3-oxo-lignoceroyl-CoA + NADPH + H+ (

i13: (3R)-3-hydroxy-behenoyl-CoA + NADP+ ← 3-oxo-behenoyl-CoA + NADPH + H+ (
i14: (3R)-3-hydroxy-cerotoyl-CoA + NADP+ ← 3-oxo-cerotoyl-CoA + NADPH + H+ (

Relationship Links: BRENDA:EC:, ENZYME:EC:, IUBMB-ExplorEnz:EC:

Created 05-Apr-2012 by Caspi R, SRI International


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

Han02a: 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

Latendresse13: Latendresse M. (2013). "Computing Gibbs Free Energy of Compounds and Reactions in MetaCyc."

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

Report Errors or Provide Feedback
Please cite the following article in publications resulting from the use of MetaCyc: Caspi et al, Nucleic Acids Research 42:D459-D471 2014
Page generated by Pathway Tools version 19.5 (software by SRI International) on Wed Feb 10, 2016, biocyc12.