Reactome | BCKDHA:BCKDHB tetramer decarboxylates KIC, KMVA, KIV

BCKDHA:BCKDHB tetramer decarboxylates KIC, KMVA, KIV

Stable Identifier

R-HSA-9859148

Type

Reaction [transition]

Species

Homo sapiens

Compartment

mitochondrial matrix

Synonyms

3-methyl-2-oxobutanoate + H(+) + N(6)-((R)-lipoyl)-L-lysyl-(dihydrolipoyllysine-residue (2-methylpropanoyl)transferase) => CO2 + N(6)-((R)-S(8)-2-methylpropanoyldihydrolipoyl)-L-lysyl-(dihydrolipoyllysine-residue (2-methylpropanoyl)transferase)

ReviewStatus

5/5

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BCKDHA:BCKDHB tetramer decarboxylates KIC, KMVA, KIV

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The E1 subunit of the mitochondrial branched-chain alpha-ketoacid dehydrogenase (BKCDH) complex consists of a tetramer of BCKDHA and BCKDHB dimers. It catalyzes the decarboxylation of alpha-ketoisocaproate (KIC), alpha-keto-beta-methylvalerate (KMVA), or alpha-ketoisovalerate (KIV), at the same time transferring the resulting isovaleryl, alpha-methylbutyryl, or isobutyryl groups onto the lipoyl moiety of the E2 component (DBT) which gets reduced in the process. The tetramer binds two thiamin diphosphate molecules and four K+ ions as cofactors (AEvarsson et al., 2000).

Literature References

PubMed ID	Title	Journal	Year
10745006	Crystal structure of human branched-chain alpha-ketoacid dehydrogenase and the molecular basis of multienzyme complex deficiency in maple syrup urine disease. Hol, WG, Turley, S, Chuang, DT, Chuang, JL, Wynn, RM, Aevarsson, A	Structure Fold Des	2000