A multi-enzyme complex that catalyzes the oxidative decarboxylation of branched-chain alpha-ketoacids derived from L-leucine, L-isoleucine, and L-valine to branched-chain acyl-CoAs. The complex comprises multiple copies of three enzymes referred to as E1, E2 and E3: branched-chain alpha-ketoacid dehydrogenase (E1, a heterotetramer of two alpha and two beta subunits), dihydrolipoyl transacylase (E2), and dihydrolipoamide dehydrogenase (E3). Additional proteins may also be present.
BKDH complex