malonyl-CoA-acyl carrier protein transacylase
M-CSA #291
In Escherichia coli Fatty acid synthesis, FAS II includes a specific malonyl-CoA:ACP transacylase (MCAT), which catalyses specifically the elongation step. The initiation of each elongation step in the fatty acid synthesis cycle requires the transfer of a malonyl moiety from the respective CoA thioester to the -SH group of the phosphopantetheine arm of the acyl carrier protein (ACP), the central component of any FAS. MCAT, along with Acyl-carrier-protein S-acetyltransferase (EC 2.3.1.38), is essential for the initiation of fatty-acid biosynthesis in bacteria. This enzyme also provides the malonyl groups for polyketide biosynthesis.
Defined by 6 residues: GLN:A-11SER:A-92LEU:A-93ARG:A-117HIS:A-201GLN:A-250