Ornithine transcarbamylase
Ornithine transcarbamylase | ||
---|---|---|
Ribbon model of the trimer according to PDB 1OTH | ||
Properties of human protein | ||
Mass / length primary structure | 322 amino acids | |
Secondary to quaternary structure | Homotrimer | |
Identifier | ||
Gene name | OTC | |
External IDs | ||
Enzyme classification | ||
EC, category | 2.1.3.3 , transferase | |
Response type | Transfer of an aminocarbonyl residue | |
Substrate | Carbamoyl phosphate + ornithine | |
Products | Phosphate + citrulline | |
Occurrence | ||
Parent taxon | Creature |
Ornithine transcarbamylase (OTC) is the enzyme that catalyzes the conversion of ornithine to citrulline . This is a partial step in the urea cycle of vertebrates , but also in the biosynthesis of the amino acid arginine in all living things. In some bacteria , arginine is broken down in the reverse reaction . In humans, OTC is found primarily in the liver and small intestine . Mutations in the OTC - gene can and familial OTC deficiency, this to hyperammonemia lead.
At 1: 14,000, OTC deficiency is the most common urea cycle defect . Two OTC variants were associated with an increased risk of Alzheimer's disease in a French study . Furthermore, in the case of a congenital deficiency during therapy with valproic acid due to hyperammonaemia, valproic acid-associated encephalopathy can occur.
Catalyzed equilibrium
An aminocarbonyl residue is transferred from carbamoyl phosphate to L-ornithine and L-citrulline is formed.
Individual evidence
- ↑ Homologues at OMA
- ↑ InterPro entry
- ↑ UniProt P00480
- ↑ Hansmannel F, Lendon C, Pasquier F, et al. : Is the ornithine transcarbamylase gene a genetic determinant of Alzheimer's disease? . In: Neurosci. Lett. . 449, No. 1, January 2009, pp. 76-80. doi : 10.1016 / j.neulet.2008.10.081 . PMID 18983895 .
- ↑ Bensemain F, Hot D, Ferreira S, et al. : Evidence for induction of the ornithine transcarbamylase expression in Alzheimer's disease . In: Mol. Psychiatry . 14, No. 1, January 2009, pp. 106-16. doi : 10.1038 / sj.mp.4002089 . PMID 17893704 .