3B8S

Crystal structure of wild-type chitinase A from Vibrio harveyi

3B8S の概要

• エントリーDOI: 10.2210/pdb3b8s/pdb
• 関連するPDBエントリー: 3B9A 3B9D 3B9E
• 分子名称: Chitinase A (2 entities in total)
• 機能のキーワード: tim-barrel, glycosidase, hydrolase
• 由来する生物種: Vibrio harveyi
• タンパク質・核酸の鎖数: 2
• 化学式量合計: 127683.54

構造登録者

Songsiriritthigul, C.,Pantoom, S.,Aguda, A.H.,Robinson, R.C.,Suginta, W. (登録日: 2007-11-01, 公開日: 2008-04-01, 最終更新日: 2024-10-09)

主引用文献

Songsiriritthigul, C.,Pantoom, S.,Aguda, A.H.,Robinson, R.C.,Suginta, W.
Crystal structures of Vibrio harveyi chitinase A complexed with chitooligosaccharides: implications for the catalytic mechanism
J.Struct.Biol., 162:491-499, 2008

PubMed Abstract: This research describes four X-ray structures of Vibrio harveyi chitinase A and its catalytically inactive mutant (E315M) in the presence and absence of substrates. The overall structure of chitinase A is that of a typical family-18 glycosyl hydrolase comprising three distinct domains: (i) the amino-terminal chitin-binding domain; (ii) the main catalytic (alpha/beta)(8) TIM-barrel domain; and (iii) the small (alpha+beta) insertion domain. The catalytic cleft of chitinase A has a long, deep groove, which contains six chitooligosaccharide ring-binding subsites (-4)(-3)(-2)(-1)(+1)(+2). The binding cleft of the ligand-free E315M is partially blocked by the C-terminal (His)(6)-tag. Structures of E315M-chitooligosaccharide complexes display a linear conformation of pentaNAG, but a bent conformation of hexaNAG. Analysis of the final 2F(o)-F(c) omit map of E315M-NAG6 reveals the existence of the linear conformation of the hexaNAG at a lower occupancy with respect to the bent conformation. These crystallographic data provide evidence that the interacting sugars undergo conformational changes prior to hydrolysis by the wild-type enzyme.

PubMed: 18467126
DOI: 10.1016/j.jsb.2008.03.008

実験手法

X-RAY DIFFRACTION (2 Å)