CATH Classification

Domain Context

CATH Clusters

Superfamily E3-binding domain
Functional Family Dihydrolipoamide acetyltransferase component of pyruvate dehydrogenase complex

Enzyme Information

2.3.1.168
Dihydrolipoyllysine-residue (2-methylpropanoyl)transferase.
based on mapping to UniProt P11182
2-methylpropanoyl-CoA + enzyme N(6)-(dihydrolipoyl)lysine = CoA + enzyme N(6)-(S-(2-methylpropanoyl)dihydrolipoyl)lysine.
-!- A multimer (24-mer) of this enzyme forms the core of the multienzyme 3-methyl-2-oxobutanoate dehydrogenase complex, and binds tightly both EC 1.2.4.4 and EC 1.8.1.4. -!- The lipoyl group of this enzyme is reductively 2-methylpropanoylated by EC 1.2.4.4, and the only observed direction catalyzed by EC 2.3.1.168 is that where this 2-methylpropanoyl is passed to coenzyme A. -!- In addition to the 2-methylpropanoyl group, formed when EC 1.2.4.4 acts on the oxoacid that corresponds with valine, this enzyme also transfers the 3-methylbutanoyl and S-2-methylbutanoyl groups, donated to it when EC 1.2.4.4 acts on the oxo acids corresponding with leucine and isoleucine.

UniProtKB Entries (1)

P09622
DLDH_HUMAN
Homo sapiens
Dihydrolipoyl dehydrogenase, mitochondrial

PDB Structure

PDB 3RNM
External Links
Method X-RAY DIFFRACTION
Organism
Primary Citation
Structural and Thermodynamic Basis for Weak Interactions between Dihydrolipoamide Dehydrogenase and Subunit-binding Domain of the Branched-chain {alpha}-Ketoacid Dehydrogenase Complex.
Brautigam, C.A., Wynn, R.M., Chuang, J.L., Naik, M.T., Young, B.B., Huang, T.H., Chuang, D.T.
J.Biol.Chem.