5GV1

Crystal structure of ENZbleach xylanase wild type

5GV1 の概要

• エントリーDOI: 10.2210/pdb5gv1/pdb
• 分子名称: Endo-1,4-beta-xylanase (2 entities in total)
• 機能のキーワード: endo-1, 4-beta-xylanase, gh11 xylanase, hydrolase
• 由来する生物種: termite gut metagenome
• タンパク質・核酸の鎖数: 1
• 化学式量合計: 35842.52

構造登録者

Chitnumsub, P.,Jaruwat, A.,Boonyapakorn, K.,Noytanom, K. (登録日: 2016-09-01, 公開日: 2017-08-30, 最終更新日: 2023-11-08)

主引用文献

Boonyapakron, K.,Jaruwat, A.,Liwnaree, B.,Nimchua, T.,Champreda, V.,Chitnumsub, P.
Structure-based protein engineering for thermostable and alkaliphilic enhancement of endo-beta-1,4-xylanase for applications in pulp bleaching
J. Biotechnol., 259:95-102, 2017

PubMed Abstract: In the pulp bleaching industry, enzymes with robust activity at high pH and temperatures are desirable for facilitating the pre-bleaching process with simplified processing and minimal use of chlorinated compounds. To engineer an enzyme for this purpose, we determined the crystal structure of the Xyn12.2 xylanase, a xylan-hydrolyzing enzyme derived from the termite gut symbiont metagenome, as the basis for structure-based protein engineering to improve Xyn12.2 stability in high heat and alkaline conditions. Engineered cysteine pairs that generated exterior disulfide bonds increased the k of Xyn12.2 variants and melting temperature at all tested conditions. These improvements led to up to 4.2-fold increases in catalytic efficiency at pH 9.0, 50°C for 1h and up to 3-fold increases at 60°C. The most effective variants, XynTT and XynTTTE, exhibited 2-3-fold increases in bagasse hydrolysis at pH 9.0 and 60°C compared to the wild-type enzyme. Overall, engineering arginines and phenylalanines for increased pK and hydrogen bonding improved enzyme catalytic efficiency at high stringency conditions. These modifications were the keys to enhancing thermostability and alkaliphilicity in our enzyme variants, with XynTT and XynTTTE being especially promising for their application to the pulp and paper industry.

PubMed: 28774672
DOI: 10.1016/j.jbiotec.2017.07.035

実験手法

X-RAY DIFFRACTION (1.5 Å)