The mitochondrial pyruvate dehydrogenase complex (PDHC) converts pyruvate to acetyl-CoA which is metabolized in the Krebs cycle. It is one of four human 2-oxoacid dehydrogenase complexes that generate CoA-activated carboxylic acids by oxidative decarboxylation of 2-oxoacids; the others are 2-oxoglutarate DH complex (OGDC, Krebs cycle), branched-chain 2-oxoacid DH complex (BCKDC, Val/Ile/Leu metabolism), and 2-oxoadipate DH complex (Lys metabolism). Some components are shared between all complexes; they include:
- Large core of multiple E2 proteins = dihydrolipoyl acyltransferase, in PDHC encoded by DLAT; PDHC also also requires E3 binding protein encoded by PDHX
- E1 heterotetramer = 2-oxoacid dehydrogenase/decarboxylase, in PDHC encoded by PDHA1 and PDH
- E3 dimer = dihydrolipoamid dehydrogenase, in all complexes encoded by DLD
All 2-oxoacid dehydrogenase complexes require the cofactors thiamine pyrophosphate (TPP), α-lipoic acid, FAD, NAD+, and coenzyme A.