1QBB

BACTERIAL CHITOBIASE COMPLEXED WITH CHITOBIOSE (DINAG)

1QBB の概要

• エントリーDOI: 10.2210/pdb1qbb/pdb
• 分子名称: CHITOBIASE, 2-acetamido-2-deoxy-beta-D-glucopyranose-(1-4)-2-acetamido-2-deoxy-beta-D-glucopyranose, SULFATE ION, ... (4 entities in total)
• 機能のキーワード: glycosyl hydrolase, chitobiase, chitinolysis, ba8-barrel
• 由来する生物種: Serratia marcescens
• 細胞内の位置: Periplasm: Q54468
• タンパク質・核酸の鎖数: 1
• 化学式量合計: 96732.55

構造登録者

Tews, I.,Perrakis, A.,Oppenheim, A.,Dauter, Z.,Wilson, K.S.,Vorgias, C.E. (登録日: 1996-06-07, 公開日: 1997-02-12, 最終更新日: 2024-11-20)

主引用文献

Tews, I.,Perrakis, A.,Oppenheim, A.,Dauter, Z.,Wilson, K.S.,Vorgias, C.E.
Bacterial chitobiase structure provides insight into catalytic mechanism and the basis of Tay-Sachs disease.
Nat.Struct.Biol., 3:638-648, 1996

PubMed Abstract: Chitin, the second most abundant polysaccharide on earth, is degraded by chitinases and chitobiases. The structure of Serratia marcescens chitobiase has been refined at 1.9 A resolution. The mature protein is folded into four domains and its active site is situated at the C-terminal end of the central (beta alpha)8-barrel. Based on the structure of the complex with the substrate disaccharide chitobiose, we propose an acid-base reaction mechanism, in which only one protein carboxylate acts as catalytic acid, while the nucleophile is the polar acetamido group of the sugar in a substrate-assisted reaction. The structural data lead to the hypothesis that the reaction proceeds with retention of anomeric configuration. The structure allows us to model the catalytic domain of the homologous hexosaminidases to give a structural rationale to pathogenic mutations that underlie Tay-Sachs and Sandhoff disease.

PubMed: 8673609
DOI: 10.1038/nsb0796-638

実験手法

X-RAY DIFFRACTION (2 Å)