1QW9

Crystal structure of a family 51 alpha-L-arabinofuranosidase in complex with 4-nitrophenyl-Ara

1QW9 の概要

• エントリーDOI: 10.2210/pdb1qw9/pdb
• 関連するPDBエントリー: 1PZ2 1PZ3 1QW8
• 分子名称: Alpha-L-arabinofuranosidase, 4-nitrophenyl alpha-L-arabinofuranoside (3 entities in total)
• 機能のキーワード: hydrolase
• 由来する生物種: Geobacillus stearothermophilus
• タンパク質・核酸の鎖数: 2
• 化学式量合計: 114996.17

構造登録者

Hoevel, K.,Shallom, D.,Niefind, K.,Belakhov, V.,Shoham, G.,Bassov, T.,Shoham, Y.,Schomburg, D. (登録日: 2003-09-01, 公開日: 2003-10-07, 最終更新日: 2024-02-14)

主引用文献

Hoevel, K.,Shallom, D.,Niefind, K.,Belakhov, V.,Shoham, G.,Baasov, T.,Shoham, Y.,Schomburg, D.
Crystal structure and snapshots along the reaction pathway of a family 51 alpha-L-arabinofuranosidase
Embo J., 22:4922-4932, 2003

PubMed Abstract: High-resolution crystal structures of alpha-L-arabinofuranosidase from Geobacillus stearothermophilus T-6, a family 51 glycosidase, are described. The enzyme is a hexamer, and each monomer is organized into two domains: a (beta/alpha)8-barrel and a 12-stranded beta sandwich with jelly-roll topology. The structures of the Michaelis complexes with natural and synthetic substrates, and of the transient covalent arabinofuranosyl-enzyme intermediate represent two stable states in the double displacement mechanism, and allow thorough examination of the catalytic mechanism. The arabinofuranose sugar is tightly bound and distorted by an extensive network of hydrogen bonds. The two catalytic residues are 4.7 A apart, and together with other conserved residues contribute to the stabilization of the oxocarbenium ion-like transition state via charge delocalization and specific protein-substrate interactions. The enzyme is an anti-protonator, and a 1.7 A electrophilic migration of the anomeric carbon takes place during the hydrolysis.

PubMed: 14517232
DOI: 10.1093/emboj/cdg494

実験手法

X-RAY DIFFRACTION (1.2 Å)