A multi-enzyme complex that catalyzes the oxidative decarboxylation of an alpha-ketoacid - pyruvate, a branched-chain alpha-ketoacid or alpha-ketoglutarate (also known as 2-oxoglutarate). The complex comprises multiple copies of three enzymes referred to as E1, E2 and E3: a dihydrolipoyl transacylase (E2) forms the core of the complex, with an alpha-ketoacid dehydrogenase (E1) and a dihydrolipoamide dehydrogenase (E3) attached through non-covalent bonds. The E1 and E2 components are specific to different alpha-ketoacid dehydrogenase complexes, whereas the E3 component is the same. Additional proteins may also be present.
dihydrolipoyl dehydrogenase complex