Fatty acid synthase

FASN
Identifiers
AliasesFASN, fatty acid synthase, Fasn, A630082H08Rik, FAS, OA-519, SDR27X1, Fatty acid synthase
External IDsOMIM: 600212; MGI: 95485; HomoloGene: 55800; GeneCards: FASN; OMA:FASN - orthologs
Orthologs
SpeciesHumanMouse
Entrez

2194

14104

Ensembl

ENSG00000169710

ENSMUSG00000025153

UniProt

P49327

P19096

RefSeq (mRNA)

NM_004104

NM_007988

RefSeq (protein)

n/a

NP_032014

Location (UCSC)Chr 17: 82.08 – 82.1 MbChr 11: 120.7 – 120.72 Mb
PubMed search
Wikidata
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Fatty acid synthase
Identifiers
EC no.2.3.1.85
CAS no.9045-77-6
Databases
IntEnzIntEnz view
BRENDABRENDA entry
ExPASyNiceZyme view
KEGGKEGG entry
MetaCycmetabolic pathway
PRIAMprofile
PDB structuresRCSB PDB PDBe PDBsum
Gene OntologyAmiGO / QuickGO
Search
PMCarticles
PubMedarticles
NCBIproteins

Fatty acid synthase (FAS) is an enzyme that in humans is encoded by the FASN gene.

Fatty acid synthase is a multi-enzyme protein that catalyzes fatty acid synthesis. It is not a single enzyme but a whole enzymatic system composed of two identical 272 kDa multifunctional polypeptides, in which substrates are handed from one functional domain to the next.

Its main function is to catalyze the synthesis of palmitate (C16:0, a long-chain saturated fatty acid) from acetyl-CoA and malonyl-CoA, in the presence of NADPH.

The fatty acids are synthesized by a series of decarboxylative Claisen condensation reactions from acetyl-CoA and malonyl-CoA. Following each round of elongation the beta keto group is reduced to the fully saturated carbon chain by the sequential action of a ketoreductase (KR), dehydratase (DH), and enoyl reductase (ER). The growing fatty acid chain is carried between these active sites while attached covalently to the phosphopantetheine prosthetic group of an acyl carrier protein (ACP), and is released by the action of a thioesterase (TE) upon reaching a carbon chain length of 16 (palmitic acid).