title: An inverting β-1,2-mannosidase belonging to glycoside hydrolase family 130 from Dyadobacter fermentans.
abstract: The glycoside hydrolase family (GH) 130 is composed of inverting phosphorylases that catalyze reversible phosphorolysis of β-D-mannosides. Here we report a glycoside hydrolase as a new member of GH130. Dfer_3176 from Dyadobacter fermentans showed no synthetic activity using α-D-mannose 1-phosphate but it released α-D-mannose from β-1,2-mannooligosaccharides with an inversion of the anomeric configuration, indicating that Dfer_3176 is a β-1,2-mannosidase. Mutational analysis indicated that two glutamic acid residues are critical for the hydrolysis of β-1,2-mannotriose. The two residues are not conserved among GH130 phosphorylases and are predicted to assist the nucleophilic attack of a water molecule in the hydrolysis of the β-D-mannosidic bond.
authors.affiliation: Faculty of Agriculture, Niigata University, Niigata 950-2181, Japan.
authors.forename: Takanori
authors.initials: T
authors.lastname: Nihira
authors.affiliation: Faculty of Agriculture, Niigata University, Niigata 950-2181, Japan.
authors.forename: Kazuhiro
authors.initials: K
authors.lastname: Chiku
authors.affiliation: Faculty of Agriculture, Niigata University, Niigata 950-2181, Japan.
authors.forename: Erika
authors.initials: E
authors.lastname: Suzuki
authors.affiliation: National Food Research Institute, National Agriculture and Food Research Organization, Tsukuba, Ibaraki 305-8642, Japan.
authors.forename: Mamoru
authors.initials: M
authors.lastname: Nishimoto
authors.affiliation: Department of Biotechnology, The University of Tokyo, 1-1-1 Yayoi, Bunkyo-ku, Tokyo 113-8657, Japan.
authors.forename: Shinya
authors.initials: S
authors.lastname: Fushinobu
authors.affiliation: National Food Research Institute, National Agriculture and Food Research Organization, Tsukuba, Ibaraki 305-8642, Japan.
authors.forename: Motomitsu
authors.initials: M
authors.lastname: Kitaoka
authors.affiliation: Faculty of Agriculture, Niigata University, Niigata 950-2181, Japan.
authors.forename: Ken'ichi
authors.initials: K
authors.lastname: Ohtsubo
authors.affiliation: Faculty of Agriculture, Niigata University, Niigata 950-2181, Japan. Electronic address: nakai@agr.niigata-u.ac.jp.
authors.forename: Hiroyuki
authors.initials: H
authors.lastname: Nakai
mesh_terms: D055162:Biocatalysis; D020134:Catalytic Domain; D041964:Cytophagaceae / Q000201:enzymology*; D006868:Hydrolysis; D007700:Kinetics; D008358:Mannose / Q000737:chemistry / Q000378:metabolism; D008361:Mannosidases / Q000737:chemistry* / Q000235:genetics / Q000302:isolation & purification / Q000378:metabolism*; D008958:Models, Molecular; D009154:Mutation; D010802:Phylogeny; D013237:Stereoisomerism; D013379:Substrate Specificity
chemical_list: D008361:Mannosidases; D008358:Mannose
keywords: Glycoside hydrolase family 130; β-1,2-Mannooligosaccharide; β-1,2-Mannosidase