3CKS

Urate oxidase complexed with 8-azaxanthine under 4.0 MPa oxygen pressure

3CKS の概要

• エントリーDOI: 10.2210/pdb3cks/pdb
• 関連するPDBエントリー: 2ZKA 2ZKB
• 分子名称: Uricase, SODIUM ION, 8-AZAXANTHINE, ... (5 entities in total)
• 機能のキーワード: uric acid degradation, gaz-protein complex, t-fold domain, acetylation, oxidoreductase, peroxisome, purine metabolism, tetramer
• 由来する生物種: Aspergillus flavus
• 細胞内の位置: Peroxisome: Q00511
• タンパク質・核酸の鎖数: 1
• 化学式量合計: 34391.68

構造登録者

Colloc'h, N.,Gabison, L.,Chiadmi, M.,Abraini, J.H.,Prange, T. (登録日: 2008-03-17, 公開日: 2008-10-07, 最終更新日: 2024-10-16)

主引用文献

Colloc'h, N.,Gabison, L.,Monard, G.,Altarsha, M.,Chiadmi, M.,Marassio, G.,Sopkova-de Oliveira Santos, J.,El Hajji, M.,Castro, B.,Abraini, J.H.,Prange, T.
Oxygen pressurized X-ray crystallography: probing the dioxygen binding site in cofactorless urate oxidase and implications for its catalytic mechanism.
Biophys.J., 95:2415-2422, 2008

PubMed Abstract: The localization of dioxygen sites in oxygen-binding proteins is a nontrivial experimental task and is often suggested through indirect methods such as using xenon or halide anions as oxygen probes. In this study, a straightforward method based on x-ray crystallography under high pressure of pure oxygen has been developed. An application is given on urate oxidase (UOX), a cofactorless enzyme that catalyzes the oxidation of uric acid to 5-hydroxyisourate in the presence of dioxygen. UOX crystals in complex with a competitive inhibitor of its natural substrate are submitted to an increasing pressure of 1.0, 2.5, or 4.0 MPa of gaseous oxygen. The results clearly show that dioxygen binds within the active site at a location where a water molecule is usually observed but does not bind in the already characterized specific hydrophobic pocket of xenon. Moreover, crystallizing UOX in the presence of a large excess of chloride (NaCl) shows that one chloride ion goes at the same location as the oxygen. The dioxygen hydrophilic environment (an asparagine, a histidine, and a threonine residues), its absence within the xenon binding site, and its location identical to a water molecule or a chloride ion suggest that the dioxygen site is mainly polar. The implication of the dioxygen location on the mechanism is discussed with respect to the experimentally suggested transient intermediates during the reaction cascade.

PubMed: 18375516
DOI: 10.1529/biophysj.107.122184

実験手法

X-RAY DIFFRACTION (1.7 Å)