Structural insight into potential cold adaptation mechanism through a psychrophilic glycoside hydrolase family 10 endo-β-1,4-xylanase.

Yingying Zheng, Yujie Li, Weidong Liu, Chun-Chi Chen, Tzu-Ping Ko, Miao He, Zhongxia Xu, Meixia Liu, Huiying Luo, Rey-Ting Guo, Bin Yao, Yanhe Ma

Index: J. Struct. Biol. 193 , 206-11, (2016)

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Abstract

The cold-adapted xylanases can catalyze at low temperature and hold great potential in food industry applications. Here we describe the first crystal structure of a cold-adapted glycoside hydrolase (GH) family 10 xylanase XynGR40 and its complex with xylobiose at 2.15 and 2.50Å resolution. The enzyme folds into a typical GH10 (β/α)8 TIM-barrel, with E132 and E243 serving as the catalytic residues. The xylobiose was observed to occupy the -1 and -2 subsites. Structural comparison with a thermophilic GH10 xylanase highlighting various parameters that may explain the cold adaptation features were analyzed. Synergistic effects of the increased exposure of hydrophobic residues, the higher flexibility of substrate-binding residues, more flexible loops, and the ratios of special amino acid residues, may result in the cold adaptation of XynGR40. Copyright © 2015 Elsevier Inc. All rights reserved.