title: Structural insight into glucose dehydrogenase from the thermoacidophilic archaeon Thermoplasma volcanium.
abstract: Glucose dehydrogenase from the thermoacidophilic archaeon Thermoplasma volcanium (tvGlcDH) is highly active towards D-glucose and D-galactose, but does not utilize aldopentoses such as D-xylose as substrates. In the present study, the crystal structures of substrate/cofactor-free tvGlcDH and of a tvGlcDH T277F mutant in a binary complex with NADP and in a ternary complex with D-glucose and nicotinic acid adenine dinucleotide phosphate, an NADP analogue, were determined at resolutions of 2.6, 2.25 and 2.33 Å, respectively. The overall structure of each monomer showed notable similarity to that of the enzyme from Sulfolobus solfataricus (ssGlcDH-1), which accepts a broad range of C5 and C6 sugars as substrates. However, the amino-acid residues of tvGlcDH involved in substrate binding markedly differed from those of ssGlcDH-1. Structural comparison revealed that a decreased number of interactions between the C3-hydroxyl group of the sugar and the enzyme are likely to be responsible for the lack of reactivity of tvGlcDH towards D-xylose.
authors.affiliation: Department of Applied Biological Science, Faculty of Agriculture, Kagawa University, 2393 Ikenobe, Miki-cho, Kita-gun, Kagawa 761-0795, Japan.
authors.forename: Yoshitaka
authors.initials: Y
authors.lastname: Kanoh
authors.affiliation: Department of Applied Biological Science, Faculty of Agriculture, Kagawa University, 2393 Ikenobe, Miki-cho, Kita-gun, Kagawa 761-0795, Japan.
authors.forename: Seiichiroh
authors.initials: S
authors.lastname: Uehara
authors.affiliation: Thermostable Enzyme Laboratory, 5-5-2 Minatojima-Minamimachi, Chuo-ku, Kobe 650-0047, Japan.
authors.forename: Hideyuki
authors.initials: H
authors.lastname: Iwata
authors.affiliation: Department of Bioscience, School of Agriculture, Tokai University, Aso, Kumamoto 869-1404, Japan.
authors.forename: Kazunari
authors.initials: K
authors.lastname: Yoneda
authors.affiliation: Department of Biomedical Engineering, Osaka Institute of Technology, 5-16-1 Ohmiya, Asahi-ku, Osaka 535-8585, Japan.
authors.forename: Toshihisa
authors.initials: T
authors.lastname: Ohshima
authors.affiliation: Department of Applied Biological Science, Faculty of Agriculture, Kagawa University, 2393 Ikenobe, Miki-cho, Kita-gun, Kagawa 761-0795, Japan.
authors.forename: Haruhiko
authors.initials: H
authors.lastname: Sakuraba
mesh_terms: D001483:Base Sequence; D001665:Binding Sites; D018360:Crystallography, X-Ray; D005947:Glucose / Q000737:chemistry / Q000378:metabolism; D042843:Glucose 1-Dehydrogenase / Q000737:chemistry* / Q000235:genetics / Q000302:isolation & purification / Q000378:metabolism*; D008958:Models, Molecular; D008969:Molecular Sequence Data; D009154:Mutation; D009249:NADP / Q000031:analogs & derivatives / Q000737:chemistry / Q000378:metabolism; D011487:Protein Conformation; D013379:Substrate Specificity; D048229:Sulfolobus solfataricus / Q000201:enzymology; D013822:Thermoplasma / Q000201:enzymology*
chemical_list: D009249:NADP; C024376:NAADP; D042843:Glucose 1-Dehydrogenase; D005947:Glucose
keywords: Thermoplasma volcanium; archaea; glucose dehydrogenase; thermophiles