Affiliation:
1. Laboratoire de Chimie Bactérienne, Marseille, France.
Abstract
A construction was carried out to obtain a high level of expression in Escherichia coli of the gene celCCA, coding for the endoglucanase A from Clostridium cellulolyticum (EGCCA). The enzyme was purified in two forms with different molecular weights, 51,000 and 44,000. The smaller protein was probably the result of proteolysis, although great care was taken to prevent this process from occurring. Evidence was found for the loss of the conserved reiterated domains which are characteristic of C. thermocellum and C. cellulolyticum cellulases. The two forms were extensively studied, and it was demonstrated that although they had the same pH and temperature optima, they differed in their catalytic properties. The truncated protein gave the more efficient catalytic parameters on carboxymethyl cellulose and showed improved endoglucanase characteristics, whereas the intact enzyme showed truer cellulase characteristics. The possible role of clostridial reiterated domains in the hydrolytic activity toward crystalline cellulose is discussed.
Publisher
American Society for Microbiology
Subject
Molecular Biology,Microbiology
Reference26 articles.
1. Aubert J.-P. P. Beguin and J. Millet. 1991. Genes and proteins involved in cellulose and xylan degradation by Clostridium thermocellum. In M. Sebald (ed) Genetics and molecular biology of anaerobic bacteria in press. Springer-Verlag New York.
2. Molecular biology of cellulose degradation. Annu;Beguin P.;Rev. Microbiol.,1990
3. Sequence of a cellulase gene of the thermophilic bacterium Clostridium thermocellum;Beguin P.;J. Bacteriol.,1985
4. Belaich J.-P. A. Belaich C. Gaudin and C. Bagnara. Genes and proteins involved in cellulose degradation by mesophilic Clostridia. In M. Sebald (ed.) Genetics and molecular biology of anaerobic bacteria in press. Springer-Verlag New York.
5. Calcium-binding affinity and calcium-enhanced activity of Clostridium thermocellum endoglucanase D;Chauvaux S.;Biochem. J.,1990
Cited by
98 articles.
订阅此论文施引文献
订阅此论文施引文献，注册后可以免费订阅5篇论文的施引文献，订阅后可以查看论文全部施引文献