DBT (gene)

• OMIM: 248 610
• UniProt: P11182

The dihydrolipoyl acyltransferase ( BCKAD -E2 ) (gene name: DBT ) is an enzyme found in all living things. It forms the E2 subunit of the branched-chain α -keto acid dehydrogenase enzyme complex that catalyzes an essential step in the degradation pathway of the branched chain amino acids valine, leucine and isoleucine. In this localized in the mitochondria in eukaryotes the complex BCKAD -E2 is contained together with its cofactor lipoic acid in 24x version. Mutations in the DBT gene can cause hereditary E2 enzyme deficiency, which is the cause of various types of rare maple syrup disease.

BCKAD -E2 catalyzes the transfer of the acyl group of the enzyme to belong Dihydrolipoyllysin -amino acid residue to a coenzyme A molecule. It acts thus analogous to dihydrolipoyl transacetylase in the pyruvate dehydrogenase complex (PDH -E2 ) or Dihydrolipoyl transsuccinylase in ketoglutarate dehydrogenase complex ( KGDH E2). As acyl 2- methylpropanoyl, but also isobutyryl, isovaleryl and acetyl accepted.