文献类型：期刊文献

英文题名：Structure-function analysis of Gynuella sunshinyii chitosanase uncovers the mechanism of substrate binding in GH family 46 members

作者：Wang, Yani[1];Qin, Zhen[2];Fan, Liqiang[1];Zhao, Liming[1,3]

机构：[1]East China Univ Sci & Technol, R&D Ctr Separat & Extract Technol Fermentat Ind, Sch Biotechnol, State Key Lab Bioreactor Engn, Shanghai 200237, Peoples R China;[2]Shanghai Univ, Sch Life Sci, Shanghai 200444, Peoples R China;[3]Shanghai Collaborat Innovat Ctr Biomfg Technol SC, Shanghai 200237, Peoples R China

年份：2020

卷号：165

起止页码：2038

外文期刊名：INTERNATIONAL JOURNAL OF BIOLOGICAL MACROMOLECULES

收录：;EI(收录号：20240915626928);WOS:【SCI-EXPANDED(收录号:WOS:000600773500043)】；

基金：This work was financially supported by the National Natural Science Foundation of China (31701537), the National Key R&D Program of China (2019YFD0901805), Shanghai Sailing Program (17YF1403500), "Chen Guang" (17CG28) project of ShanghaiMunicipal Education Commission and Shanghai Education Development Foundation, the 111 Project (B18022) and Research Program of State Key Laboratory of Bioreactor Engineering.

语种：英文

外文关键词：Chitooligosaccharides; Chitosanase; Complex structure; Substrate recognition; GH family 46

摘要：Chitooligosaccharides (COS) is a kind of functional carbohydrates with great application potential as its various biological functions in food, cosmetics, and pharmaceutical fields. Exploring the relationship between structure and function of chitosanase is essential for the controllable preparation of chitooligosaccharides with the specific degree of polymerization (DP). GsCsn46A is a cold-adapted glycosyl hydrolase (GH) family 46 chitosanase with application potential for the controllable preparation of chitooligosaccharides. Here, we present two complex structures with substrate chitopentaose and chitotetraose of GsCsn46A, respectively. The overall structure of GsCsn46A contains nine alpha-helices and two beta-strands that folds into two globular domainswith the substrate between them. The unique binding positions of both chitopentaose and chitotetraose revealed two novel sugar residues in the negatively-numbered subsites of GH family 46 chitosanases. The structure-function analysis of GsCsn46A uncovers the substrate binding and catalysis mechanism of GH family 46 chitosanases. Structural basis mutagenesis in GsCsn46A indicated that altering interactions near+3 subsite would help produce hydrolysis productswith higher DP. Specifically, themutant N21Wof GsCsn46A nearly eliminated the ability of hydrolyzing chitotetraose after long-time degradation. (C) 2020 Elsevier B.V. All rights reserved.