A hyperthermostable D-ribose-5-phosphate isomerase from Pyrococcus horikoshii characterization and three-dimensional structure.
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.
Ishikawa
Kazuhiko
K
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
Matsui
Ikuo
I
Payan
Francoise
F
Cambillau
Christian
C
Ishida
Hiroyasu
H
Kawarabayasi
Yutaka
Y
Kikuchi
Hisasi
H
Roussel
Alain
A
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
D011994:Recombinant Proteins; D019747:Aldose-Ketose Isomerases; C022548:ribosephosphate isomerase