title: A hyperthermostable D-ribose-5-phosphate isomerase from Pyrococcus horikoshii characterization and three-dimensional structure.
abstract: A gene homologous to D-ribose-5-phosphate isomerase (EC 5.3.1.6) was found in the genome of Pyrococcus horikoshii. D-ribose-5-phosphate isomerase (PRI) is of particular metabolic importance since it catalyzes the interconversion between the ribose and ribulose forms involved in the pentose phosphate cycle and in the process of photosynthesis. The gene consisting of 687 bp was overexpressed in Escherichia coli, and the resulting enzyme showed activity at high temperatures with an optimum over 90 degrees C. The crystal structures of the enzyme, free and in complex with D-4-phosphoerythronic acid inhibitor, were determined. PRI is a tetramer in the crystal and in solution, and each monomer has a new fold consisting of two alpha/beta domains. The 3D structures and the characterization of different mutants indicate a direct or indirect catalytic role for the residues E107, D85, and K98.
authors.affiliation: AFMB UMR-6098, CNRS et Universités d'Aix-Marseille I et II, 31 Chemin Joseph Aiguier, 13402 20, Marseille Cedex, France. kazu-ishikawa@aist.go.jp
authors.forename: Kazuhiko
authors.initials: K
authors.lastname: Ishikawa
authors.forename: Ikuo
authors.initials: I
authors.lastname: Matsui
authors.forename: Francoise
authors.initials: F
authors.lastname: Payan
authors.forename: Christian
authors.initials: C
authors.lastname: Cambillau
authors.forename: Hiroyasu
authors.initials: H
authors.lastname: Ishida
authors.forename: Yutaka
authors.initials: Y
authors.lastname: Kawarabayasi
authors.forename: Hisasi
authors.initials: H
authors.lastname: Kikuchi
authors.forename: Alain
authors.initials: A
authors.lastname: Roussel
mesh_terms: D019747:Aldose-Ketose Isomerases / Q000037:antagonists & inhibitors / Q000737:chemistry* / Q000378:metabolism; D000595:Amino Acid Sequence; D001665:Binding Sites; D002942:Circular Dichroism; D018360:Crystallography, X-Ray; D006358:Hot Temperature; D008969:Molecular Sequence Data; D020836:Protein Structure, Quaternary; D017433:Protein Structure, Secondary; D017434:Protein Structure, Tertiary; D019711:Pyrococcus / Q000201:enzymology* / Q000378:metabolism; D011994:Recombinant Proteins / Q000037:antagonists & inhibitors / Q000378:metabolism; D016415:Sequence Alignment
chemical_list: D011994:Recombinant Proteins; D019747:Aldose-Ketose Isomerases; C022548:ribosephosphate isomerase