title: A mechanism of glucose tolerance and stimulation of GH1 β-glucosidases.
abstract: β-Glucosidases are enzymes that hydrolyze β-glycosidic bonds to release non-reducing terminal glucosyl residues from glycosides and oligosaccharides, and thus have significant application potential in industries. However, most β-glucosidases are feedback inhibited by the glucose product, which restricts their application. Remarkably, some β-glucosidases of the glycoside hydrolase (GH) 1 family are tolerant to or even stimulated by glucose. Elucidation of the mechanisms of glucose tolerance and stimulation of the GH1 β-glucosidases will be crucial to improve their application through enzyme engineering. In this study, by comparing the primary and tertiary structures of two GH1 β-glucosidases with distinct glucose dependence, some putative glucose-dependence relevant sites were mutated to investigate their exact roles. Both biochemical and structural characterization of the mutants suggested that some sites at the entrance and middle of the substrate channel regulate the effects of glucose, and the relative binding affinity/preference of these sites to glucose modulates the glucose dependence. A mechanism was therefore proposed to interpret the glucose dependence of GH1 β-glucosidases. This research provides fresh insight into our current understanding of the properties and mechanisms of GH1 β-glycosidases and related enzymes that modulate their activity via feedback control mechanism.
authors.affiliation: School of Life Sciences, Anhui University, Hefei, Anhui 230601, China.|Anhui Provincial Engineering Technology Research Center of Microorganisms and Biocatalysis, Hefei, Anhui 230601, China.
authors.forename: Yang
authors.initials: Y
authors.lastname: Yang
authors.affiliation: School of Life Sciences, Anhui University, Hefei, Anhui 230601, China.|Anhui Provincial Engineering Technology Research Center of Microorganisms and Biocatalysis, Hefei, Anhui 230601, China.
authors.forename: Xinxin
authors.initials: X
authors.lastname: Zhang
authors.affiliation: School of Life Sciences, Anhui University, Hefei, Anhui 230601, China.|Anhui Provincial Engineering Technology Research Center of Microorganisms and Biocatalysis, Hefei, Anhui 230601, China.
authors.forename: Qiang
authors.initials: Q
authors.lastname: Yin
authors.affiliation: School of Life Sciences, Anhui University, Hefei, Anhui 230601, China.|Anhui Provincial Engineering Technology Research Center of Microorganisms and Biocatalysis, Hefei, Anhui 230601, China.
authors.forename: Wei
authors.initials: W
authors.lastname: Fang
authors.affiliation: School of Life Sciences, Anhui University, Hefei, Anhui 230601, China.|Anhui Provincial Engineering Technology Research Center of Microorganisms and Biocatalysis, Hefei, Anhui 230601, China.
authors.forename: Zemin
authors.initials: Z
authors.lastname: Fang
authors.affiliation: Department of Chemistry &Biochemistry, Florida International University, Miami, Florida 33199, United States.
authors.forename: Xiaotang
authors.initials: X
authors.lastname: Wang
authors.affiliation: School of Life Sciences, Anhui University, Hefei, Anhui 230601, China.|Anhui Provincial Engineering Technology Research Center of Microorganisms and Biocatalysis, Hefei, Anhui 230601, China.
authors.forename: Xuecheng
authors.initials: X
authors.lastname: Zhang
authors.affiliation: School of Life Sciences, Anhui University, Hefei, Anhui 230601, China.|Anhui Provincial Engineering Technology Research Center of Microorganisms and Biocatalysis, Hefei, Anhui 230601, China.
authors.forename: Yazhong
authors.initials: Y
authors.lastname: Xiao
mesh_terms: D000595:Amino Acid Sequence; D001665:Binding Sites; D030562:Databases, Protein; D000068536:Bacillota / Q000201:enzymology; D005947:Glucose / Q000737:chemistry / Q000378:metabolism*; D006026:Glycoside Hydrolases / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D006031:Glycosylation; D007700:Kinetics; D062105:Molecular Docking Simulation; D016297:Mutagenesis, Site-Directed; D056507:Paenibacillus / Q000201:enzymology; D017434:Protein Structure, Tertiary; D013379:Substrate Specificity; D013816:Thermodynamics
chemical_list: D006026:Glycoside Hydrolases; D005947:Glucose