Broadening the Substrate Specificity of Cellobiose Phosphorylase from Clostridium thermocellum for Improved Transformation of Cellodextrin to Starch.

ABSTRACT: Cellobiose phosphorylase (CBP) catalyzes the reversible phosphorolysis of cellobiose into α-glucose 1-phosphate and glucose. A CBP with a broadened substrate specificity would be more desirable when utilized to convert cellulose into amylose (PNAS, 110: 7182-7187, 2013) and to construct yeast that can phosphorolytically use cellodextrin to produce ethanol. Based on the structure differences in the catalytic loops of CBP and cellodextrin phosphorylase from Clostridium thermocellum (named CtCBP and CtCDP, respectively), CtCBP was mutated to change its substrate specificity. A single-site mutant S497G was identified to exhibit a 5.7-fold higher catalytic efficiency with cellotriose as a substrate in the phosphorolytic reaction compared to the wild type, without any loss of catal

SUBMITTER: Zhang Y 

PROVIDER: S-EPMC10572201 | biostudies-literature | 2023 Sep

REPOSITORIES: biostudies-literature