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1ivr
From Proteopedia
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| , resolution 2.4Å | |||||||
|---|---|---|---|---|---|---|---|
| Ligands: | |||||||
| Activity: | Aspartate transaminase, with EC number 2.6.1.1 | ||||||
| Resources: | FirstGlance, OCA, PDBsum, RCSB | ||||||
| Coordinates: | save as pdb, mmCIF, xml | ||||||
STRUCTURE OF ASPARTATE AMINOTRANSFERASE
Overview
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.
About this Structure
1IVR is a Single protein structure of sequence from Gallus gallus. Full crystallographic information is available from OCA.
Reference
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
Page seeded by OCA on Sun Mar 30 21:25:18 2008
