Reaction: 2-oxoglutarate + [dihydrolipoyllysine-residue succinyltransferase] lipoyllysine = [dihydrolipoyllysine-residue succinyltransferase] S-succinyldihydrolipoyllysine + CO2
For diagram of reaction click here and for mechanism click here.
Glossary: dihydrolipoyl group
thiamine diphosphate
Other name(s): 2-ketoglutarate dehydrogenase; 2-oxoglutarate dehydrogenase; 2-oxoglutarate: lipoate oxidoreductase; 2-oxoglutarate:lipoamide 2-oxidoreductase (decarboxylating and acceptor-succinylating); α-ketoglutarate dehydrogenase; alphaketoglutaric acid dehydrogenase; α-ketoglutaric dehydrogenase; α-oxoglutarate dehydrogenase; AKGDH; OGDC; ketoglutaric dehydrogenase; oxoglutarate decarboxylase (misleading); oxoglutarate dehydrogenase; oxoglutarate dehydrogenase (lipoamide)
Systematic name: 2-oxoglutarate:[dihydrolipoyllysine-residue succinyltransferase]-lipoyllysine 2-oxidoreductase (decarboxylating, acceptor-succinylating)
Comments: Contains thiamine diphosphate. It is a component of the multienzyme 2-oxoglutarate dehydrogenase complex, EC 1.2.1.105, in which multiple copies of it are bound to a core of molecules of EC 2.3.1.61, dihydrolipoyllysine-residue succinyltransferase, which also binds multiple copies of EC 1.8.1.4, dihydrolipoyl dehydrogenase. It does not act on free lipoamide or lipoyllysine, but only on the lipoyllysine residue in EC 2.3.1.61.
Links to other databases: BRENDA, EXPASY, KEGG, Metacyc, PDB, CAS registry number: 9031-02-1
References:
1. Massey, V. The composition of the ketoglutarate dehydrogenase complex. Biochim. Biophys. Acta 38 (1960) 447-460.
2. Ochoa, S. Enzymic mechanisms in the citric acid cycle. Adv. Enzymol. Relat. Subj. Biochem. 15 (1954) 183-270.
3. Sanadi, D.R., Littlefield, J.W. and Bock, R.M. Studies on α-ketoglutaric oxidase. II. Purification and properties. J. Biol. Chem.,197 (1952) 851-862.
4. Perham, R.N. Swinging arms and swinging domains in multifunctional enzymes: catalytic machines for multistep reactions. Annu. Rev. Biochem., 69, (2000) 961-1004. [PMID: 10966480]