6JGO

Crystal structure of barley exohydrolaseI W434H mutant in complex with 4I,4III,4V-S-trithiocellohexaose

6JGO の概要

• エントリーDOI: 10.2210/pdb6jgo/pdb
• 関連するBIRD辞書のPRD_ID: PRD_900034
• 分子名称: BETA-D-GLUCAN GLUCOHYDROLASE ISOENZYME EXO1, beta-D-glucopyranose-(1-4)-4-thio-beta-D-glucopyranose, 2-acetamido-2-deoxy-beta-D-glucopyranose, ... (8 entities in total)
• 機能のキーワード: barley exohydrolasei, hydrolase, enzyme function
• 由来する生物種: Hordeum vulgare subsp. vulgare (Domesticated barley)
• タンパク質・核酸の鎖数: 1
• 化学式量合計: 68519.61

構造登録者

Luang, S.,Streltsov, V.A.,Hrmova, M. (登録日: 2019-02-14, 公開日: 2020-08-19, 最終更新日: 2024-11-06)

主引用文献

Luang, S.,Fernandez-Luengo, X.,Nin-Hill, A.,Streltsov, V.A.,Schwerdt, J.G.,Alonso-Gil, S.,Ketudat Cairns, J.R.,Pradeau, S.,Fort, S.,Marechal, J.D.,Masgrau, L.,Rovira, C.,Hrmova, M.
The evolutionary advantage of an aromatic clamp in plant family 3 glycoside exo-hydrolases.
Nat Commun, 13:5577-5577, 2022

PubMed Abstract: In the barley β-D-glucan glucohydrolase, a glycoside hydrolase family 3 (GH3) enzyme, the Trp286/Trp434 clamp ensures β-D-glucosides binding, which is fundamental for substrate hydrolysis during plant growth and development. We employ mutagenesis, high-resolution X-ray crystallography, and multi-scale molecular modelling methods to examine the binding and conformational behaviour of isomeric β-D-glucosides during substrate-product assisted processive catalysis that operates in GH3 hydrolases. Enzyme kinetics reveals that the W434H mutant retains broad specificity, while W434A behaves as a strict (1,3)-β-D-glucosidase. Investigations of reactant movements on the nanoscale reveal that processivity is sensitive to mutation-specific alterations of the tryptophan clamp. While wild-type and W434H utilise a lateral cavity for glucose displacement and sliding of (1,3)-linked hydrolytic products through the catalytic site without dissociation, consistent with their high hydrolytic rates, W434A does not adopt processive catalysis. Phylogenomic analyses of GH3 hydrolases disclose the evolutionary advantage of the tryptophan clamp that confers broad specificity, high catalytic efficiency, and processivity.

PubMed: 36151080
DOI: 10.1038/s41467-022-33180-5

実験手法

X-RAY DIFFRACTION (1.95 Å)