Structural highlights
Function
[AATM_CHICK] Catalyzes the irreversible transamination of the L-tryptophan metabolite L-kynurenine to form kynurenic acid (KA). Plays a key role in amino acid metabolism. Important for metabolite exchange between mitochondria and cytosol. May facilitate cellular uptake of long-chain free fatty acids (By similarity).
Evolutionary Conservation
Check, as determined by ConSurfDB. You may read the explanation of the method and the full data available from ConSurf.
Publication Abstract from PubMed
The crystal structure of mitochondrial aspartate aminotransferase (mAAT) of chicken complexed with erythro-beta-hydroxyaspartate has been determined at 2.4 A resolution. Pregrown crystals of mAAT complexed with the inhibitor maleate (closed enzyme conformation, orthorhombic space group C222(1)) were soaked in solutions of erythro-beta-hydroxyaspartate. The ligand exchange was monitored by microspectrophotometry. The active site turned out to be predominantly occupied by the carbinolamine intermediate. The carbinolamine is a true intermediate of the catalytic cycle forming the last covalently bound enzyme:substrate complex before release of the keto acid product. Occupancies of approximately 80% for the carbinolamine and of approximately 20% for the quinonoid intermediate were obtained. Two hydrogen bonds were identified that are potentially relevant for the accumulation of the carbinolamine intermediate: one to the hydroxyl group of Tyr 70* and the other to the epsilon-NH2 group of Lys 258.
Aspartate aminotransferase complexed with erythro-beta-hydroxyaspartate: crystallographic and spectroscopic identification of the carbinolamine intermediate.,von Stosch AG Biochemistry. 1996 Dec 3;35(48):15260-8. PMID:8952476[1]
From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.
References
- ↑ von Stosch AG. Aspartate aminotransferase complexed with erythro-beta-hydroxyaspartate: crystallographic and spectroscopic identification of the carbinolamine intermediate. Biochemistry. 1996 Dec 3;35(48):15260-8. PMID:8952476 doi:10.1021/bi960994z
