Expression, purification and subunit‐binding properties of cohesins 2 and 3 of the Clostridium thermocellum cellulosome

FEBS Letters

Lamed, Raphael³  Bayer, Edward A²  Shoham, Yuval¹  Yaron, Sima¹  Morag, Ely² 

[1] Department of Food Engineering and Biotechnology, Technion-Israel Institute of Technology, Haifa, Israel;Department of Biophysics, The Weizmann Institute of Science, Rehovot, Israel;Department of Molecular Microbiology and Biotechnology, Tel Aviv University, Ramat Aviv, Israel

关键词: Cellulosome (Clostridium thermocellum);    Cellulase;    Multi-enzyme complex;    Scaffoldin;    Cohesin domain;    Subunit-integrating domain;   

DOI  :  10.1016/0014-5793(95)00074-J

学科分类：生物化学/生物物理

来源: John Wiley & Sons Ltd.

【 摘 要 】

The enzymatic subunits of the cellulosome of Clostridium thermocellum are integrated into the complex by a major non-catalytic polypeptide, called scaffoldin. Its numerous functional domains include a single cellulose-binding domain (CBD) and nine subunit-binding domains, or cohesin domains. Two of the cohesin domains, together with the adjacent CBD, have been cloned and expressed in Escherichia coli, and the recombinant constructs were purified by affinity chromatography on a cellulosic matrix. Both cohesin domains, which differ by about 30% in their primary structure, showed a similar binding profile to the cellulosomal subunits. Calcium ions enhanced dramatically this binding. Under the conditions of the assay, only one major catalytic subunit of the cellulosome failed to bind to either cohesin domain. The results indicate a lack of selectivity in the binding of cohesin domains to the catalytic subunits and also suggest that additional mechanisms may be involved in cellulosome assembly.

【 授权许可】

Unknown