May play a role in the biosynthesis of lipoic acid as well as longer chain fatty acids required for optimal mitochondrial function. a fatty acyl-[ACP] + H(+) + malonyl-[ACP] = a 3-oxoacyl-[ACP] + CO2 + holo-[ACP] butanoyl-[ACP] + H(+) + malonyl-[ACP] = 3-oxohexanoyl-[ACP] + CO2 + holo-[ACP] H(+) + hexanoyl-[ACP] + malonyl-[ACP] = 3-oxooctanoyl-[ACP] + CO2 + holo-[ACP] H(+) + malonyl-[ACP] + octanoyl-[ACP] = 3-oxodecanoyl-[ACP] + CO2 + holo-[ACP] decanoyl-[ACP] + H(+) + malonyl-[ACP] = 3-oxododecanoyl-[ACP] + CO2 + holo-[ACP] dodecanoyl-[ACP] + H(+) + malonyl-[ACP] = 3-oxotetradecanoyl-[ACP] + CO2 + holo-[ACP] H(+) + malonyl-[ACP] + tetradecanoyl-[ACP] = 3-oxohexadecanoyl-[ACP] + CO2 + holo-[ACP] Lipid metabolism; fatty acid biosynthesis. Belongs to the thiolase-like superfamily. Beta-ketoacyl-ACP synthases family.