title: A glycoside hydrolase family 31 dextranase with high transglucosylation activity from Flavobacterium johnsoniae.
abstract: Glycoside hydrolase family (GH) 31 enzymes exhibit various substrate specificities, although the majority of members are α-glucosidases. Here, we constructed a heterologous expression system of a GH31 enzyme, Fjoh_4430, from Flavobacterium johnsoniae NBRC 14942, using Escherichia coli, and characterized its enzymatic properties. The enzyme hydrolyzed dextran and pullulan to produce isomaltooligosaccharides and isopanose, respectively. When isomaltose was used as a substrate, the enzyme catalyzed disproportionation to form isomaltooligosaccharides. The enzyme also acted, albeit inefficiently, on p-nitrophenyl α-D-glucopyranoside, and p-nitrophenyl α-isomaltoside was the main product of the reaction. In contrast, Fjoh_4430 did not act on trehalose, kojibiose, nigerose, maltose, maltotriose, or soluble starch. The optimal pH and temperature were pH 6.0 and 60 °C, respectively. Our results indicate that Fjoh_4430 is a novel GH31 dextranase with high transglucosylation activity.
authors.affiliation: a Department of Applied Biological Science , Tokyo University of Agriculture and Technology , Fuchu , Japan.
authors.forename: Yoshifumi
authors.initials: Y
authors.lastname: Gozu
authors.affiliation: a Department of Applied Biological Science , Tokyo University of Agriculture and Technology , Fuchu , Japan.
authors.forename: Yuichi
authors.initials: Y
authors.lastname: Ishizaki
authors.affiliation: a Department of Applied Biological Science , Tokyo University of Agriculture and Technology , Fuchu , Japan.
authors.forename: Yuhei
authors.initials: Y
authors.lastname: Hosoyama
authors.affiliation: a Department of Applied Biological Science , Tokyo University of Agriculture and Technology , Fuchu , Japan.
authors.forename: Takatsugu
authors.initials: T
authors.lastname: Miyazaki
authors.affiliation: a Department of Applied Biological Science , Tokyo University of Agriculture and Technology , Fuchu , Japan.
authors.forename: Atsushi
authors.initials: A
authors.lastname: Nishikawa
authors.affiliation: a Department of Applied Biological Science , Tokyo University of Agriculture and Technology , Fuchu , Japan.
authors.forename: Takashi
authors.initials: T
authors.lastname: Tonozuka
mesh_terms: D001426:Bacterial Proteins / Q000235:genetics / Q000378:metabolism*; D003910:Dextranase / Q000235:genetics / Q000378:metabolism*; D003911:Dextrans / Q000737:chemistry / Q000378:metabolism*; D004926:Escherichia coli / Q000201:enzymology* / Q000235:genetics; D005417:Flavobacterium / Q000201:enzymology* / Q000235:genetics; D005936:Glucans / Q000737:chemistry / Q000378:metabolism; D005964:Glucosyltransferases / Q000235:genetics / Q000378:metabolism*; D006863:Hydrogen-Ion Concentration; D006868:Hydrolysis; D007534:Isomaltose / Q000737:chemistry / Q000378:metabolism; D009844:Oligosaccharides / Q000737:chemistry / Q000378:metabolism; D015202:Protein Engineering; D011994:Recombinant Proteins / Q000235:genetics / Q000378:metabolism; D013379:Substrate Specificity; D013696:Temperature
chemical_list: D001426:Bacterial Proteins; D003911:Dextrans; D005936:Glucans; D009844:Oligosaccharides; D011994:Recombinant Proteins; C021705:maltooligosaccharides; D007534:Isomaltose; C009109:pullulan; D005964:Glucosyltransferases; D003910:Dextranase
keywords: Flavobacterium johnsoniae; GH31; dextran; glucosyltransferase; isomaltose