Fatty acid synthase

1XKT, 2CG5, 2JFD, 2JFK, 2PX6, 3HHD, 3TJM, 4PIV, 4W82, 4W9N, 4Z49, 5C37219414104ENSG00000169710ENSMUSG00000025153P49327P19096NM_004104NM_007988NP_004095NP_032014Fatty acid synthase (FAS) is an enzyme that in humans is encoded by the FASN gene.1xkt: Human fatty acid synthase: Structure and substrate selectivity of the thioesterase domain2cg5: STRUCTURE OF AMINOADIPATE-SEMIALDEHYDE DEHYDROGENASE-PHOSPHOPANTETHEINYL TRANSFERASE IN COMPLEX WITH CYTOSOLIC ACYL CARRIER PROTEIN AND COENZYME A2jfd: STRUCTURE OF THE MAT DOMAIN OF HUMAN FAS2jfk: STRUCTURE OF THE MAT DOMAIN OF HUMAN FAS WITH MALONYL-COA 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).