MetaCyc Reaction:

Superclasses: Reactions Classified By Conversion Type Simple Reactions Chemical Reactions Protein-Modification Reactions
Reactions Classified By Substrate Macromolecule Reactions Protein-Reactions Protein-Modification Reactions

EC Number: , ,

Enzymes and Genes:

Arabidopsis thaliana col : 3-oxoacyl-[acyl-carrier-protein] reductase, chloroplastic Inferred from experiment : AT1G24360
Escherichia coli K-12 substr. MG1655 : 3-oxoacyl-[acyl-carrier-protein] reductase : fabG
Homo sapiens : fatty acid synthase : FASN
Mycobacterium tuberculosis H37Rv : fatty acid synthase Inferred by computational analysis : fas
Pseudomonas aeruginosa : NADPH-dependent β-ketoacyl reductase : rhlG
Saccharomyces cerevisiae : fatty acid synthase, α subunit : FAS2

In Pathway: palmitate biosynthesis I (animals and fungi) , palmitate biosynthesis II (bacteria and plants)

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.

Direct generic reaction:
a (3R)-3-hydroxyacyl-[acyl-carrier protein] + NADP+ ← a 3-oxoacyl-[acp] + NADPH + H+ (

Enzyme Commission Primary Name for 3-oxoacyl-[acyl-carrier-protein] reductase

Enzyme Commission Synonyms for β-ketoacyl-[acyl-carrier protein](ACP) reductase, β-ketoacyl acyl carrier protein (ACP) reductase, β-ketoacyl reductase, β-ketoacyl thioester reductase, β-ketoacyl-ACP reductase, β-ketoacyl-acyl carrier protein reductase, 3-ketoacyl acyl carrier protein reductase, NADPH-specific 3-oxoacyl-[acylcarrier protein]reductase, 3-oxoacyl-[ACP]reductase, (3R)-3-hydroxyacyl-[acyl-carrier-protein]:NADP+ oxidoreductase

Enzyme Commission Primary Name for fatty-acid synthase

Enzyme Commission Synonyms for FASN (gene name)

Enzyme Commission Primary Name for fatty-acyl-CoA synthase

Enzyme Commission Synonyms for yeast fatty acid synthase, FAS1 (gene name), FAS2 (gene name)

Standard Gibbs Free Energy (ΔrG in kcal/mol): 20.375793 Inferred by computational analysis [Latendresse13]

Enzyme Commission Summary for
Exhibits a marked preference for acyl-carrier-protein derivatives over CoA derivatives as substrates.

Enzyme Commission Summary for
The animal enzyme is a multi-functional protein catalysing the reactions of EC, [acyl-carrier-protein] S-acetyltransferase, EC, [acyl-carrier-protein] S-malonyltransferase, EC, β-ketoacyl-[acyl-carrier-protein] synthase I, EC, 3-oxoacyl-[acyl-carrier-protein] reductase, EC, 3-hydroxyacyl-[acyl-carrier-protein] dehydratase, EC, enoyl-[acyl-carrier-protein] reductase (NADPH, Re-specific) and EC, oleoyl-[acyl-carrier-protein] hydrolase. cf. EC, fatty-acyl-CoA synthase.

Enzyme Commission Summary for
The enzyme from yeasts (Ascomycota and Basidiomycota) is a multi-functional protein complex composed of two subunits. One subunit catalyses the reactions EC, 3-oxoacyl-[acyl-carrier-protein] reductase and EC, β-ketoacyl-[acyl-carrier-protein] synthase I, while the other subunit catalyses the reactions of EC, [acyl-carrier-protein] S-acetyltransferase, EC, [acyl-carrier-protein] S-malonyltransferase, EC, 3-hydroxyacyl-[acyl-carrier-protein] dehydratase, EC, enoyl-[acyl-carrier-protein] reductase (NADPH, Si-specific) and EC, (R)-3-hydroxyacid-ester dehydrogenase. The enzyme differs from the animal enzyme (EC in that the enoyl reductase domain requires FMN as a cofactor, and the ultimate product is an acyl-CoA (usually palmitoyl-CoA) instead of a free fatty acid.

Citations: [Prescott72, Shimakata82, Toomey66, Stoops79, Wakil83, Schweizer73, Tehlivets07]

Gene-Reaction Schematic: ?

Gene-Reaction Schematic

Instance reaction of [a (3R)-3-hydroxyacyl-[acyl-carrier protein] + NADP+ ← a 3-oxoacyl-[acp] + NADPH + H+] (
i1: a (3R)-3-hydroxyoctanoyl-[acp] + NADP+ ← a 3-oxo-octanoyl-[acp] + NADPH + H+ (

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


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

Prescott72: Prescott DJ, Vagelos PR (1972). "Acyl carrier protein." Adv Enzymol Relat Areas Mol Biol 36;269-311. PMID: 4561013

Schweizer73: Schweizer E, Kniep B, Castorph H, Holzner U (1973). "Pantetheine-free mutants of the yeast fatty-acid-synthetase complex." Eur J Biochem 39(2);353-62. PMID: 4590449

Shimakata82: Shimakata T, Stumpf PK (1982). "Purification and characterizations of beta-Ketoacyl-[acyl-carrier-protein] reductase, beta-hydroxyacyl-[acyl-carrier-protein] dehydrase, and enoyl-[acyl-carrier-protein] reductase from Spinacia oleracea leaves." Arch Biochem Biophys 218(1);77-91. PMID: 6756317

Stoops79: Stoops JK, Ross P, Arslanian MJ, Aune KC, Wakil SJ, Oliver RM (1979). "Physicochemical studies of the rat liver and adipose fatty acid synthetases." J Biol Chem 254(15);7418-26. PMID: 457689

Tehlivets07: Tehlivets O, Scheuringer K, Kohlwein SD (2007). "Fatty acid synthesis and elongation in yeast." Biochim Biophys Acta 1771(3);255-70. PMID: 16950653

Toomey66: Toomey RE, Wakil SJ (1966). "Studies on the mechanism of fatty acid synthesis. XV. Preparation and general properties of beta-ketoacyl acyl carrier protein reductase from Escherichia coli." Biochim Biophys Acta 116(2);189-97. PMID: 4381013

Wakil83: Wakil SJ, Stoops JK, Joshi VC (1983). "Fatty acid synthesis and its regulation." Annu Rev Biochem 52;537-79. PMID: 6137188

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 SRI International Pathway Tools version 19.0 on Sat Apr 18, 2015, biocyc13.