InterPro domain: IPR034616

The branched-chain alpha-keto dehydrogenase complex catalyzes the overall conversion of alpha-keto acids to acyl-CoA and CO2. It is a multienzyme complex composed of 3 functional components: (E1) branched-chain alpha-keto acid decarboxylase or 2-oxoisovalerate dehydrogenase; (E2) lipoamide acyltransferase; (E3) lipoamide dehydrogenase. The E1 subunit contains two components, E1 alpha and E1 beta [ 1 ]. This entry represents the alpha chain of E1 from prokaryotes and eukaryotes [ 2 ].

The 2-oxoisovalerate dehydrogenase ( 1.2.4.4 ) of the branched-chain 2-oxo acid dehydrogenase complex is specific for 2-oxoisovalerate and related 2-oxo acids derived from the branched-chain amino acids valine, leucine and isoleucine [ 3 ].

1. Structural organization and chromosomal localization of the gene for the E1 beta subunit of human branched chain alpha-keto acid dehydrogenase. J. Biol. Chem. 266, 14686-91
2. Similarity of the E1 subunits of branched-chain-oxoacid dehydrogenase from Pseudomonas putida to the corresponding subunits of mammalian branched-chain-oxoacid and pyruvate dehydrogenases. Eur. J. Biochem. 176, 311-7
3. Crystal structure of 2-oxoisovalerate and dehydrogenase and the architecture of 2-oxo acid dehydrogenase multienzyme complexes. Nat. Struct. Biol. 6, 785-92