3B9G

Crystal structure of loop deletion mutant of Trypanosoma vivax nucleoside hydrolase (3GTvNH) in complex with ImmH

3B9G の概要

• エントリーDOI: 10.2210/pdb3b9g/pdb
• 関連するPDBエントリー: 1HOZ 1HPO 1KIC 1KIE 1R4F 2MAS
• 分子名称: IAG-nucleoside hydrolase, CALCIUM ION, SODIUM ION, ... (5 entities in total)
• 機能のキーワード: rossmann fold, flexible loop deletion, transition state complex, hydrolase
• 由来する生物種: Trypanosoma vivax; 詳細
• タンパク質・核酸の鎖数: 2
• 化学式量合計: 73290.50

構造登録者

Vandemeulebroucke, A.,De Vos, S.,Van Holsbeke, E.,Steyaert, J.,Versees, W. (登録日: 2007-11-05, 公開日: 2008-04-22, 最終更新日: 2023-09-20)

主引用文献

Vandemeulebroucke, A.,De Vos, S.,Van Holsbeke, E.,Steyaert, J.,Versees, W.
A Flexible Loop as a Functional Element in the Catalytic Mechanism of Nucleoside Hydrolase from Trypanosoma vivax.
J.Biol.Chem., 283:22272-22282, 2008

PubMed Abstract: The nucleoside hydrolase of Trypanosoma vivax hydrolyzes the N-glycosidic bond of purine nucleosides. Structural and kinetic studies on this enzyme have suggested a catalytic role for a flexible loop in the vicinity of the active sites. Here we present the analysis of the role of this flexible loop via the combination of a proline scan of the loop, loop deletion mutagenesis, steady state and pre-steady state analysis, and x-ray crystallography. Our analysis reveals that this loop has an important role in leaving group activation and product release. The catalytic role involves the entire loop and could only be perturbed by deletion of the entire loop and not by single site mutagenesis. We present evidence that the loop closes over the active site during catalysis, thereby ordering a water channel that is involved in leaving group activation. Once chemistry has taken place, the loop dynamics determine the rate of product release.

PubMed: 18519562
DOI: 10.1074/jbc.M803705200

実験手法

X-RAY DIFFRACTION (1.4 Å)