In enzymology and molecular biology, a holo-[acyl-carrier-protein] synthase (ACPS, EC 2.7.8.7) is an enzyme that catalyzes the chemical reaction: CoA-[4'-phosphopantetheine] + apo-acyl carrier protein adenosine 3',5'-bisphosphate + holo-acyl carrier protein This enzyme belongs to the family of transferases, specifically those transferring non-standard substituted phosphate groups. It is also known as 4'-phosphopantetheinyl transferase after the group it transfers.