1IVR
STRUCTURE OF ASPARTATE AMINOTRANSFERASE
Summary for 1IVR
| Entry DOI | 10.2210/pdb1ivr/pdb |
| Descriptor | ASPARTATE AMINOTRANSFERASE, N-PYRIDOXYL-2,3-DIHYDROXYASPARTIC ACID-5-MONOPHOSPHATE (3 entities in total) |
| Functional Keywords | aspartate aminotransferase, erythro-beta-hydroxyaspartate, carbinolamine, aminotransferase |
| Biological source | Gallus gallus (chicken) |
| Total number of polymer chains | 1 |
| Total formula weight | 45388.73 |
| Authors | Graf Von Stosch, A. (deposition date: 1996-10-11, release date: 1997-07-23, Last modification date: 2024-02-07) |
| Primary citation | von Stosch, A.G. Aspartate aminotransferase complexed with erythro-beta-hydroxyaspartate: crystallographic and spectroscopic identification of the carbinolamine intermediate. Biochemistry, 35:15260-15268, 1996 Cited by PubMed Abstract: 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. PubMed: 8952476DOI: 10.1021/bi960994z PDB entries with the same primary citation |
| Experimental method | X-RAY DIFFRACTION (2.4 Å) |
Structure validation
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