The pyruvate dehydrogenase complex catalyzes the overall conversion of pyruvate to acetyl-CoA and CO(2). (R)-N(6)-lipoyl-L-lysyl-[dihydrolipoyllysine-residue acetyltransferase] + H(+) + pyruvate = (R)-N(6)-(S(8)-acetyldihydrolipoyl)-L-lysyl-[dihydrolipoyllysine-residue acetyltransferase] + CO2 Pyruvate dehydrogenase (E1) is a tetramer of 2 alpha and 2 beta subunits. Eukaryotic pyruvate dehydrogenase (PDH) complexes are organized as a core consisting of the oligomeric dihydrolipoamide acetyl-transferase (E2), around which are arranged multiple copies of pyruvate dehydrogenase (E1), dihydrolipoamide dehydrogenase (E3) and protein X (E3BP) bound by non-covalent bonds. Present with 9970 molecules/cell in log phase SD medium.