In enzymology, a [acyl-carrier-protein] S-acetyltransferase () is an enzyme that catalyzes the reversible chemical reaction
Thus, the two substrates of this enzyme are acetyl-CoA and acyl carrier protein, whereas its two products are CoA and acetyl-acyl-carrier-protein.
This enzyme belongs to the family of transferases, specifically those acyltransferases transferring groups other than aminoacyl groups. The systematic name of this enzyme class is acetyl-CoA:[acyl-carrier-protein] S-acetyltransferase. Other names in common use include acetyl coenzyme A-acyl-carrier-protein transacylase, acetyl-CoA:ACP transacylase, [acyl-carrier-protein]acetyltransferase, [ACP]acetyltransferase, and ACAT. This enzyme participates in fatty acid biosynthesis.
As of late 2007, only one structure has been solved for this class of enzymes, with the PDB accession code .