Crystal structure and identification of a key amino acid for glucose tolerance, substrate specificity and transglycosylation activity of metagenomic beta-glucosidase Td2F2
β-Glucosidase Td2F2 isolated from a compost metagenome has high glucose tolerance and transglycosylation activity. In this study, we determined the high-resolution crystal structure of Td2F2. It has a unique structure at the -1 subsite that is import ...
β-Glucosidase Td2F2 isolated from a compost metagenome has high glucose tolerance and transglycosylation activity. In this study, we determined the high-resolution crystal structure of Td2F2. It has a unique structure at the -1 subsite that is important for substrate specificity but not for glucose tolerance. To elucidate the mechanism(s) of glucose tolerance, we isolated a glucose-sensitive Td2F2 mutant using random mutagenesis. In this mutant, Asn223 residue located between subsites +1 and +2 was mutated. The Asn223 mutation resulted in reduced glucose tolerance and transglycosylation activity, and drastically changed substrate specificity. These results indicate that the structure between subsites +1 and +2 is critical for the glucose tolerance and substrate specificity of Td2F2. Our findings shed light on the glucose tolerance and transglycosylation activity mechanisms of glycoside hydrolase family 1 β-glucosidases.
Related Citations:
Characterization of a novel beta-glucosidase from a compost microbial metagenome with strong transglycosylation activity Uchiyama, T.,Miyazaki, K.,Yaoi, K. (2013) J.Biol.Chem. 288: 18325
Organizational Affiliation:
Department of Computational Biology and Medical Sciences, Graduate School of Frontier Sciences, The University of Tokyo, Chiba, Japan.,Bioproduction Research Institute, National Institute of Advanced Industrial Science and Technology (AIST), Tsukuba, Ibaraki, Japan.,Department of Biomaterial Sciences, Graduate School of Agricultural and Life Sciences, The University of Tokyo, Japan.,Department of Biotechnology, The University of Tokyo, Japan.
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