3-oxotetradecanoyl-[acyl-carrier protein] [CPD:C05759];
The enzyme, characterized from mycobacteria, provides a link between the type I and type II fatty acid synthase systems (FAS-I and FAS-II, respectively) found in these organisms. The enzyme acts on medium- and long-chain acyl-CoAs (C12-C16) produced by the FAS-I system, condensing them with malonyl-[acyl-carrier protein] (malonyl-AcpM) and forming starter molecules for the FAS-II system, which elongates them into meromycolic acids. The enzyme has no activity with short-chain acyl-CoAs (e.g. acetyl-CoA), which are used by EC 188.8.131.52, beta-ketoacyl-[acyl-carrier-protein] synthase III, or branched-chain acyl-CoAs, which are used by EC 184.108.40.2060, branched-chain beta-ketoacyl-[acyl-carrier-protein] synthase.