Ornithine aminotransferase
| ornithine aminotransferase | |||||||||
|---|---|---|---|---|---|---|---|---|---|
ExPASy NiceZyme view | | ||||||||
| KEGG | KEGG entry | ||||||||
| MetaCyc | metabolic pathway | ||||||||
| PRIAM | profile | ||||||||
| PDB structures | RCSB PDB PDBe PDBsum | ||||||||
| Gene Ontology | AmiGO / QuickGO | ||||||||
| |||||||||
| ornithine aminotransferase | |||||||
|---|---|---|---|---|---|---|---|
| Identifiers | |||||||
| Symbol | OAT | ||||||
Chr. 10 q26 | |||||||
| |||||||
Ornithine aminotransferase (OAT) is an enzyme which is encoded in human by the OAT gene located on chromosome 10.
The OAT involved in the ultimate formation of the
Structure
The OAT gene encodes for a protein that is approximately 46 kDa in size. The OAT protein is expressed primarily in the liver and the kidney but also in the brain and the retina.[1] The OAT protein is localized to the mitochondrion within the cells where it is expressed.[2]
The structure of the OAT protein has been resolved using X-ray crystallography and shows similarity to other subgroup 2 aminotransferases such as
Function
Ornithine aminotransferase catalyzes the transfer of the delta-amino group from L-ornithine
- L-ornithine + a 2-oxo acid = L-glutamate 5-semialdehyde + an L-amino acid
The reaction requires
Clinical significance
Mutations in the OAT gene can lead to malfunctioning proteins, including both point mutations that abolish catalytic activities, large frame-shift mutations, as well as mutated proteins that are not properly targeted to the mitochondrion where its normal functionality occurs.[2] In the latter, abnormality of mitochondrial import causes ectopic accumulation of the OAT protein in the cytosol followed by rapid degradation by proteolysis. Deficiency of OAT activities causes ornithine aminotransferase deficiency, also known as gyrate atrophy of choroid and retina.[4][5][6][7]
The mechanism of gyrate atrophy of choroid and retina is thought to involve the toxicity of
See also
References
External links
- Ornithine+aminotransferase at the U.S. National Library of Medicine Medical Subject Headings (MeSH)
- Seiler N (September 2000). "Ornithine aminotransferase, a potential target for the treatment of hyperammonemias". Curr Drug Targets. 1 (2): 119–53. PMID 11465067.
