Component of the pyruvate dehydrogenase (PDH) complex, that 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 Homodimer. Part of the PDH complex, consisting of multiple copies of pyruvate dehydrogenase (E1), dihydrolipoamide acetyltransferase (E2) and lipoamide dehydrogenase (E3).