α-ketoglutarate dehydrogenase E1

α-ketoglutarate dehydrogenase E1
	Ribbon / surface model of the KDH-E1 dimer from Escherichia coli with thiamine analog as a calotte, according to PDB 2GDJ
Properties of human protein
Mass / length primary structure	983 amino acids
Cofactor	TPP
Identifier
Gene name	OGDH
External IDs	OMIM : 613022 ; UniProt : Q02218 ;
Enzyme classification
EC, category	1.2.4.2 , oxidoreductases
Response type	Decarboxylation, succinylation
Substrate	2-ketoglutarate + lipoyllysine DLST
Products	Succinyl lipoyl lysine DLST + CO 2
Occurrence
Parent taxon	Bacteria , eukaryotes
	Orthologue

α-Ketoglutarate dehydrogenase E1 is the enzyme in bacteria and eukaryotes which, as an E1 subunit of the α-ketoglutarate dehydrogenase complex, catalyzes the decarboxylation of α-ketoglutarate . This reaction is part of the citric acid cycle . In addition, α-ketoadipate can be decarboxylated, which is necessary for the breakdown of the amino acid lysine . The protein complex is located in the mitochondria . Rare mutations in OGDH - gene can and E1 deficiency of the rare Ketoglutarazidurie lead.

Catalyzed reaction

The decarboxylation of ketoglutarate place on thiamine as catalytic center instead of forming an atomic bond with ketoglutarate, so succinyl thiamine - pyrophosphate with elimination of CO ₂ is produced.

+ + CO ₂ (R = OOC-CH ₂ -CH ₂ -) ${\ displaystyle \ longrightarrow}$
${\ displaystyle \ longrightarrow}$

This succinyl residue (syn. Succinic acid ) of the TPP is taken over by the α-lipoic acid ( oxidation ). It is covalently bound to the Lipoat DSLT subunit. S-succinyl hydrolip (oat / onamide) is formed.

+ + (R = OOC-CH ₂ -CH ₂ -) ${\ displaystyle \ longrightarrow}$

The reaction is thus equivalent to the decarboxylation of pyruvate by pyruvate dehydrogenase E1 .

literature

Bunik V, Kaehne T, Degtyarev D, Shcherbakova T, Reiser G: Novel isoenzyme of 2-oxoglutarate dehydrogenase is identified in brain, but not in heart . In: FEBS J . . 275, No. 20, October 2008, pp. 4990-5006. doi : 10.1111 / j.1742-4658.2008.06632.x . PMID 18783430 .

Individual evidence

↑ UniProt Q02218
↑ Orphanet: Oxoglutaric aciduria

Web links

Wikibooks: Biochemistry and Pathobiochemistry: Alpha-Ketoglutarate Dehydrogenase - Learning and Teaching Materials

Wikibooks: Biochemistry and Pathobiochemistry: Keto Acid Dehydrogenase Complexes - Learning and Teaching Materials

reactome: alpha-ketoglutarate + CoASH + NAD + ⇒ succinyl-CoA + CO2 + NADH + H +

[1] UniProt Q02218

[2] Orphanet: Oxoglutaric aciduria