2BFG

crystal structure of beta-xylosidase (fam GH39) in complex with dinitrophenyl-beta-xyloside and covalently bound xyloside

2BFG の概要

• エントリーDOI: 10.2210/pdb2bfg/pdb
• 関連するPDBエントリー: 1W91 2BS9
• 分子名称: BETA-XYLOSIDASE, SODIUM ION, 2,5-DINITROPHENOL, ... (7 entities in total)
• 機能のキーワード: hydrolase, family gh39, thermophilic enzyme
• 由来する生物種: BACILLUS STEAROTHERMOPHILUS
• タンパク質・核酸の鎖数: 8
• 化学式量合計: 466828.28

構造登録者

Czjzek, M.,Bravman, T.,Henrissat, B.,Shoham, Y. (登録日: 2004-12-07, 公開日: 2005-10-12, 最終更新日: 2025-10-01)

主引用文献

Czjzek, M.,David, A.B.,Bravman, T.,Shoham, G.,Henrissat, B.,Shoham, Y.
Enzyme-Substrate Complex Structures of a Gh39 Beta-Xylosidase from Geobacillus Stearothermophilus.
J.Mol.Biol., 353:838-, 2005

PubMed Abstract: Beta-D-Xylosidases are glycoside hydrolases that catalyse the release of xylose units from short xylooligosaccharides and are engaged in the final breakdown of plant cell-wall hemicelluloses. beta-D-Xylosidases are found in glycoside hydrolase families 3, 39, 43, 52 and 54. The first crystal structure of a GH39 beta-xylosidase revealed a multi-domain organization with the catalytic domain having the canonical (beta/alpha)8 barrel fold. Here, we report the crystal structure of the GH39 Geobacillus stearothermophilus beta-D-xylosidase, inactivated by a point mutation of the general acid-base residue E160A, in complex with the chromogenic substrate molecule 2,5-dinitrophenyl-beta-D-xyloside. Surprisingly, six of the eight active sites present in the crystallographic asymmetric unit contain the trapped covalent glycosyl-enzyme intermediate, while two of them still contain the uncleaved substrate. The structural characterization of these two critical species along the reaction coordinate of this enzyme identifies the residues forming its xyloside-binding pocket as well as those essential for its aglycone recognition.

PubMed: 16212978
DOI: 10.1016/J.JMB.2005.09.003

実験手法

X-RAY DIFFRACTION (2.4 Å)