title: 3-O-α-D-glucopyranosyl-L-rhamnose phosphorylase from Clostridium phytofermentans.
abstract: We found an unreported activity of phosphorylase catalyzed by a protein (Cphy1019) belonging to glycoside hydrolase family 65 (GH65) from Clostridium phytofermentans. The recombinant Cphy1019 produced in Escherichia coli did not phosphorolyze α-linked glucobioses, such as trehalose (α1-α1), kojibiose (α1-2), nigerose (α1-3), and maltose (α1-4), which are typical substrates for GH65 enzymes. In reverse phosphorolysis, Cphy1019 utilized only l-rhamnose as the acceptor among various sugars examined with β-d-glucose 1-phosphate as the donor. The reaction product was determined to be 3-O-α-d-glucopyranosyl-l-rhamnose, indicating strict α1-3 regioselectivity. We propose 3-O-α-d-glucopyranosyl-l-rhamnose: phosphate β-d-glucosyltransferase as the systematic name and 3-O-α-d-glucopyranosyl-l-rhamnose phosphorylase as the short name for this novel GH65 phosphorylase.
authors.affiliation: Faculty of Agriculture, Niigata University, Niigata, Japan.
authors.forename: Takanori
authors.initials: T
authors.lastname: Nihira
authors.forename: Hiroyuki
authors.initials: H
authors.lastname: Nakai
authors.forename: Motomitsu
authors.initials: M
authors.lastname: Kitaoka
mesh_terms: D003013:Clostridium / Q000201:enzymology*; D004187:Disaccharides / Q000737:chemistry / Q000378:metabolism*; D005964:Glucosyltransferases / Q000737:chemistry / Q000378:metabolism*; D006863:Hydrogen-Ion Concentration; D007700:Kinetics; D006005:Phosphorylases / Q000235:genetics / Q000302:isolation & purification / Q000378:metabolism*; D013237:Stereoisomerism; D013379:Substrate Specificity; D013696:Temperature
chemical_list: D004187:Disaccharides; C572446:3-O-alpha-D-glucopyranosyl-L-rhamnose phosphate beta-D-glucosyltransferase, Clostridium phytofermentans; D005964:Glucosyltransferases; D006005:Phosphorylases