Brun E, Gans P, Marion D, Barras F
LCB-CNRS, Marseille, France.
Eur J Biochem. 1995 Jul 1;231(1):142-8.
EGZ is the major endoglucanase secreted by Erwinia chrysanthemi. Functional characterization indicates that it is made of a catalytic N-terminal domain linked to a C-terminal cellulose-binding domain (CBD) by a Ser/Thr-rich linker. A chimeric plasmid, in which the CBD-encoding region was fused downstream of the ompA signal sequence, was constructed and introduced into Escherichia coli. This allowed for the production of processed and disulfide-bonded CBD, mostly recovered from the culture supernatant of E. coli. One-dimensional NMR analysis of the purified CBD reveals that it folds into a well-structured domain. Moreover, comparison with the one-dimensional NMR analysis of full-length EGZ strongly suggests that the CBD folds autonomously, providing experimental support for the existence of domains of EGZ.
EGZ是菊欧文氏菌分泌的主要内切葡聚糖酶。功能特性表明，它由一个催化性的N端结构域通过富含丝氨酸/苏氨酸的连接子与一个C端纤维素结合结构域（CBD）相连组成。构建了一个嵌合质粒，其中编码CBD的区域融合在ompA信号序列的下游，并将其导入大肠杆菌。这使得能够产生经过加工且形成二硫键的CBD，大部分从大肠杆菌的培养上清液中回收。对纯化的CBD进行的一维核磁共振分析表明，它折叠成一个结构良好的结构域。此外，与全长EGZ的一维核磁共振分析结果比较强烈表明，CBD能够自主折叠，为EGZ结构域的存在提供了实验支持。
