title: Structural insights into the substrate recognition properties of beta-glucosidase.
abstract: Beta-glucosidase enzymes (EC 3.2.1-3.2.3) hydrolyze sugars and are implicated in a wide spectrum of biological processes. Recently, we reported that beta-glucosidase has varied kinetic parameters for the natural and synthetic substrates [K.H Nam, S.J. Kim, M.Y. Kim, J.H. Kim, T.S. Yeo, C.M. Lee, H.K Jun, K.Y. Hwang. Crystal structure of engineered beta-glucosidase from a soil metagenome, Proteins 73 (2008) 788-793]. However, an understanding of the kinetic values of beta-glucosidase has not yet enabled the elucidation of its molecular function. Here, we report the X-ray crystal structure of beta-glucosidase with a glucose and cellobiose fragment from uncultured soil metagenome. From the various crystals, we obtained the pre-reaction (native), intermediate (disaccharide cleavage) and post-reaction (glucose binding) states of the active site pocket. These structures provide snapshots of the catalytic processing of beta-glucosidase. In addition, the intermediate state of the crystal structure provides insight into the substrate specificity of beta-glucosidase. These structural studies will facilitate elucidation of the architectural mechanism responsible for the substrate recognition of beta-glucosidase.
authors.affiliation: Division of Biotechnology, College of Life Sciences & Biotechnology, Korea University, Seoul 136-701, South Korea.
authors.forename: Ki Hyun
authors.initials: KH
authors.lastname: Nam
authors.forename: Min Woo
authors.initials: MW
authors.lastname: Sung
authors.forename: Kwang Yeon
authors.initials: KY
authors.lastname: Hwang
mesh_terms: D002384:Catalysis; D020134:Catalytic Domain; D002475:Cellobiose / Q000737:chemistry; D018360:Crystallography, X-Ray; D005947:Glucose / Q000737:chemistry; D054892:Metagenome; D011487:Protein Conformation; D012988:Soil Microbiology; D013379:Substrate Specificity; D001617:beta-Glucosidase / Q000737:chemistry* / Q000235:genetics
chemical_list: D002475:Cellobiose; D001617:beta-Glucosidase; D005947:Glucose