Ketoacyl-acyl carrier protein synthase III (KASIII) initiates the elongation in type II fatty acid synthase systems. It is found in bacteria and plants. Elongation of fatty acids in the type II systems occurs by Claisen condensation of malonyl-acyl carrier protein (ACP) with acyl-ACP. KASIII initiates this process by specifically using acetyl-CoA over acyl-CoA.
Jiyao W et al.(2023). "The conserved domain database in 2023.",