Directed Evolution of Clostridium thermocellum β-Glucosidase A Towards Enhanced Thermostability.

ABSTRACT: β-Glucosidases are key enzymes in the process of cellulose utilization. It is the last enzyme in the cellulose hydrolysis chain, which converts cellobiose to glucose. Since cellobiose is known to have a feedback inhibitory effect on a variety of cellulases, β-glucosidase can prevent this inhibition by hydrolyzing cellobiose to non-inhibitory glucose. While the optimal temperature of the Clostridium thermocellum cellulosome is 70 °C, C. thermocellum β-glucosidase A is almost inactive at such high temperatures. Thus, in the current study, a random mutagenesis directed evolutionary approach was conducted to produce a thermostable mutant with K_cat and K_m, similar to those of the wild-type enzyme. The resultant mutant contained two mutations, A17S and K268N,

SUBMITTER: Yoav S 

PROVIDER: S-EPMC6801902 | biostudies-literature | 2019 Sep

REPOSITORIES: biostudies-literature