Dihydrolipoyllysine-residue acyltransferase component of branched-chain alpha-ketoacid dehydrogenase complex (EC 2.3.1.168) (Branched-chain alpha-ketoacid dehydrogenase complex component E2) (BCKADH E2) (Dihydrolipoyllysine-residue (2-methylpropanoyl)transferase)