Essential role of the family-22 carbohydrate-binding modules for β-1,3-1,4-glucanase activity of Clostridium stercorarium Xyn10B

被引：33

作者：

Araki, R ^{[1
]}

Ali, MK ^{[1
]}

Sakka, M ^{[1
]}

Kimura, T ^{[1
]}

Sakka, K ^{[1
]}

Ohmiya, K ^{[1
]}

机构：

[1] Mie Univ, Fac Bioresources, Tsu, Mie 5148507, Japan

来源：

FEBS LETTERS | 2004年 / 561卷 / 1-3期

关键词：

xylanase; carbohydrate-binding module; substrate specificity; thermostabilizing module; Clostridium stercorarium;

D O I：

10.1016/S0014-5793(04)00160-7

中图分类号：

Q5 [生物化学]; Q7 [分子生物学];

学科分类号：

071010 ; 081704 ;

摘要：

Clostridium stercorarium Xyn10B is a modular enzyme comprising two family-22 carbohydrate-binding modules (CBMs), a family-10 catalytic module of glycoside hydrolases, a family-9 CBM, and two S-layer homologous modules consecutively from the N-terminus. To investigate the role of the family-22 CBMs, truncated proteins were constructed: a recombinant catalytic module polypeptide (rCD), a CBM polypeptide composed of two family-22 CBMs (rCBM) and a polypeptide composed of the family-22 CBMs and the catalytic module (rCBM-CD). We found that rCBM-CD was highly active toward beta-1,3-1,4-glucan; however, rCD was negligibly active toward the same substrate. The V-max/K-m value of rCBM-CD for beta-1,3-1,4-glucan was 7.8 times larger than that for oat-spelt xylan, indicating that rCBM-CD should be specified as a beta-1,3-1,4-glucanase rather than a xylanase despite the fact that family-10 catalytic modules are well-known xylanase modules. These results indicate that the family-22 CBMs in rCBM-CD are essential for hydrolysis of beta-1,3-1,4-glucan. (C) 2004 Federation of European Biochemical Societies. Published by Elsevier B.V. All rights reserved.

引用

页码：155 / 158

页数：4

共 22 条

[1] Importance of the carbohydrate-binding module of Clostridium stercorarium Xyn10B to xylan hydrolysis [J].