Fatty acid synthetase catalyzes the formation of long-chain fatty acids from acetyl-CoA, malonyl-CoA and NADPH. The alpha subunit contains domains for: acyl carrier protein, 3-oxoacyl-[acyl-carrier-protein] reductase, and 3-oxoacyl-[acyl-carrier-protein] synthase. This subunit coordinates the binding of the six beta subunits to the enzyme complex. acetyl-CoA + 2n H(+) + n malonyl-CoA + 2n NADPH = a long-chain fatty acyl-CoA + n CO2 + n CoA + H2O + 2n NADP(+) a fatty acyl-[ACP] + H(+) + malonyl-[ACP] = a 3-oxoacyl-[ACP] + CO2 + holo-[ACP] a (3R)-hydroxyacyl-[ACP] + NADP(+) = a 3-oxoacyl-[ACP] + H(+) + NADPH Inhibited by cerulenin by covalent binding to active site of the ketoacyl synthase (KS) region. [Alpha(6)beta(6)] hexamers of two multifunctional subunits (alpha and beta). 4'-phosphopantetheine is transferred from CoA to a specific serine of the Acyl carrier domain by the C-terminal PPT domain. This modification is essential for activity because fatty acids are bound in thioester linkage to the sulfhydryl of the prosthetic group. Present with 17000 molecules/cell in log phase SD medium. Belongs to the thiolase-like superfamily. Fungal fatty acid synthetase subunit alpha family.