Involved in the biosynthesis of methyl-branched alkylpyrones. Pks11 catalyzes the extension of medium- and long-chain aliphatic acyl-CoA substrates by using malonyl-CoA and methylmalonyl-CoA as extender molecules to synthesize polyketide products. Palmitoyl-CoA or a similar long chain fatty acid derivative is the likely substrate in vivo. Lipid metabolism; fatty acid biosynthesis. Homodimer. Belongs to the thiolase-like superfamily. Chalcone/stilbene synthases family.