Lipoamide dehydrogenase is a component of the alpha-ketoacid dehydrogenase complexes. This includes the pyruvate dehydrogenase complex, which catalyzes the overall conversion of pyruvate to acetyl-CoA and CO(2). Acts also as component of the glycine cleavage system (glycine decarboxylase complex), which catalyzes the degradation of glycine. (R)-N(6)-dihydrolipoyl-L-lysyl-[protein] + NAD(+) = (R)-N(6)-lipoyl-L-lysyl-[protein] + H(+) + NADH Binds 1 FAD per subunit. LPD1 is a homodimer. 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. LPD1 is a component of the glycine decarboxylase complex (GDC), which is composed of four proteins: P, T, L and H. The active site is a redox-active disulfide bond. Present with 24600 molecules/cell in log phase SD medium. Belongs to the class-I pyridine nucleotide-disulfide oxidoreductase family.