Updated BioCyc iOS App now
available in iTunes store
Updated BioCyc iOS App now
available in iTunes store
Updated BioCyc iOS App now
available in iTunes store
Updated BioCyc iOS App now
available in iTunes store
Updated BioCyc iOS App now
available in iTunes store

MetaCyc Reaction:

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

EC Number:

Enzymes and Genes:

Saccharomyces cerevisiae: fatty acid synthaseInferred from experiment: FAS2, FAS1

In Pathway: fatty acids biosynthesis (yeast)

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: Marked as unbalanced.

Enzyme Commission Primary Name: fatty-acyl-CoA synthase

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

Enzyme Commission Summary:
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: [Schweizer73, Wakil83, Tehlivets07]

Gene-Reaction Schematic

Gene-Reaction Schematic

Instance reactions of [a (3R)-3-hydroxyacyl-[acyl-carrier protein] + NADP+ ← a 3-oxoacyl-[acp] + NADPH + H+] (
i1: a (3R)-3-hydroxy-docosapentaenoyl-[acp] + NADP+ = a 3-oxo-docosapentaenoyl [acp] + NADPH + H+ (

i2: a (3R)-3-hydroxyoctanoyl-[acp] + NADP+ ← a 3-oxo-octanoyl-[acp] + NADPH + H+ (

i3: a (3R)-3-hydroxybutanoyl-[acp] + NADP+ ← an acetoacetyl-[acp] + NADPH + H+ (

i4: a (3R)-3-hydroxydecanoyl-[acp] + NADP+ ← a 3-oxo-decanoyl-[acp] + NADPH + H+ (

i5: a (3R)-3-hydroxypalmitoyl-[acp] + NADP+ ← a 3-oxo-palmitoyl-[acp] + NADPH + H+ (

i6: a (3R)-3-hydroxyarachidoyl-[acp] + NADP+ ← a 3-oxo-arachidoyl-[acp] + NADPH + H+ (

i7: a (3R)-3-hydroxybehenoyl-[acp] + NADP+ = a 3-oxo-behenoyl-[acp] + NADPH + H+ (

i8: a (3R)-3-hydroxycerotoyl-[acp] + NADP+ ← a 3-oxo-cerotoyl-[acp] + NADPH + H+ (

i9: a (3R)-3-hydroxydodecanoyl-[acp] + NADP+ ← a 3-oxo-dodecanoyl-[acp] + NADPH + H+ (

i10: a (3R)-3-hydroxyhexanoyl-[acp] + NADP+ ← a 3-oxo-hexanoyl-[acp] + NADPH + H+ (

i11: a (3R)-3-hydroxylignoceroyl-[acp] + NADP+ ← a 3-oxo-lignoceroyl-[acp] + NADPH + H+ (

i12: a (3R)-3-hydroxymyristoyl-[acp] + NADP+ ← a 3-oxo-myristoyl-[acp] + NADPH + H+ (

i13: a (3R)-3-hydroxystearoyl-[acp] + NADP+ ← a 3-oxo-stearoyl-[acp] + NADPH + H+ (

Instance reactions of [a 2,3,4-saturated fatty acyl-[acp] + NADP+ ← a trans-2-enoyl-[acyl-carrier protein] + NADPH + H+] (
i14: a decanoyl-[acp] + NADP+ ← a (2E)-dec-2-enoyl-[acp] + NADPH + H+ (

i15: a dodecanoyl-[acp] + NADP+ ← a (2E)-dodec-2-enoyl-[acp] + NADPH + H+ (

i16: a hexanoyl-[acyl-carrier-protein] + NADP+ ← a trans hex-2-enoyl-[acp] + NADPH + H+ (

i17: a myristoyl-[acp] + NADP+ ← a trans tetradec-2-enoyl-[acp] + NADPH + H+ (

i18: an octanoyl-[acp] + NADP+ ← a trans oct-2-enoyl-[acp] + NADPH + H+ (

i19: a palmitoyl-[acp] + NADP+ ← a trans hexadecenoyl-[acp] + NADPH + H+ (

i20: a stearoyl-[acp] + NADP+ ← a trans-octadec-2-enoyl-[acp] + NADPH + H+ (

Unification Links: KEGG:R05190

Relationship Links: BRENDA:EC:, ENZYME:EC:, IUBMB-ExplorEnz:EC:, UniProt:RELATED-TO:P07149, UniProt:RELATED-TO:P34229, UniProt:RELATED-TO:P34731, UniProt:RELATED-TO:Q9UUG0

Revised 27-Sep-2012 by Caspi R, SRI International


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

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

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 Pathway Tools version 19.5 (software by SRI International) on Mon Feb 8, 2016, biocyc13.