ornithine aminotransferase (Ornithine-oxo-acid aminotransferase, OAT)

Function

• amino-acid biosynthesis; L-proline biosynthesis
• L-glutamate 5-semialdehyde from L-ornithine: step 1/1
• catalyzes transfer of an amino group from ornithine to alpha-ketoglutarate yielding glutamic-5-semi-aldehyde & glutamic acid

L-ornithine + a 2-oxo acid
            <-->
L-glutamate 5-semialdehyde + an L-amino acid

Cofactor: pyridoxal phosphate

Structure

• homotetramer
• belongs to the class-3 pyridoxal-phosphate-dependent aminotransferase family

Compartment

mitochondrial matrix

Pathology

• defects in OAT are the cause of hyperornithinemia

More general terms

• aminotransferase
• mitochondrial protein

Database

• UniProt: http://www.uniprot.org/uniprot/P04181.html
• Kegg: http://www.genome.jp/dbget-bin/www_bget?hsa:4942
• OMIM: https://mirror.omim.org/entry/258870
• OMIM: https://mirror.omim.org/entry/311240
• OMIM: https://mirror.omim.org/entry/311241