3A3V

Crystal structure of reducing-end-xylose releasing exo-oligoxylanase Y198F mutant

3A3V の概要

• エントリーDOI: 10.2210/pdb3a3v/pdb
• 分子名称: Xylanase Y, NICKEL (II) ION, GLYCEROL, ... (4 entities in total)
• 機能のキーワード: hydrolase, xylan degradation
• 由来する生物種: Bacillus halodurans
• タンパク質・核酸の鎖数: 1
• 化学式量合計: 46539.87

構造登録者

Hidaka, M.,Fushinobu, S.,Honda, Y.,Kitaoka, M. (登録日: 2009-06-22, 公開日: 2009-11-03, 最終更新日: 2023-11-01)

主引用文献

Hidaka, M.,Fushinobu, S.,Honda, Y.,Wakagi, T.,Shoun, H.,Kitaoka, M.
Structural explanation for the acquisition of glycosynthase activity
J.Biochem., 147:237-244, 2010

PubMed Abstract: Glycosynthases are engineered glycoside hydrolases (GHs) that catalyse the synthesis of glycoside from glycosyl-fluoride donors and suitable acceptors. We have determined five crystal structures of the glycosynthase mutants reducing-end xylose-releasing exo-oligoxylanase, an inverting GH, that exhibit various levels of glycosynthetic activities. At the active site of the Y198F mutant, the most efficient glycosynthase, a water molecule is observed at the same position as nucleophilic water (NW) in the parent enzyme, and the loss of the fixation of the direction of the lone pair of water molecules in the mutant drastically decreases hydrolytic activity. Water molecules were also observed at each active site of the general base mutant, but they were shifted 1.0-3.0 A from the NW in the wild type. Their positions exhibited a strong correlation with the strength of glycosynthase activity. Here, we propose that a structural prerequisite for the sufficient glycosynthase reaction is the presence of a water molecule at the NW position, and mutation at the NW holder provides a general strategy for inverting GHs. The idea on the position of a water molecule may also be applicable to the design of efficient glycosynthases from retaining GHs.

PubMed: 19819900
DOI: 10.1093/jb/mvp159

実験手法

X-RAY DIFFRACTION (1.39 Å)