Component of the pyruvate dehydrogenase (PDH) complex, that catalyzes the overall conversion of pyruvate to acetyl-CoA and CO(2). AceE has reductase activity with pyruvate but does not react with 2-oxoglutarate (By similarity). (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 AceE (E1), DlaT (E2) and Lpd (E3).