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Uridine Phosphorylase (uridine + phosphorylase)

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Chemistry100%

Selected Abstracts

Crystallization and preliminary X-ray diffraction analysis of Salmonella typhimurium uridine phosphorylase complexed with 5-fluorouracil

ACTA CRYSTALLOGRAPHICA SECTION F (ELECTRONIC), Issue 6 2009
A. A. Lashkov
Uridine phosphorylase (UPh; EC 2.4.2.3) catalyzes the phosphorolytic cleavage of the N-glycosidic bond of uridine to form ribose 1-phosphate and uracil. This enzyme also activates pyrimidine-containing drugs, including 5-fluorouracil (5-FU). In order to better understand the mechanism of the enzyme,drug interaction, the complex of Salmonella typhimurium UPh with 5-FU was cocrystallized using the hanging-drop vapour-diffusion method at 294,K. X-ray diffraction data were collected to 2.2,Å resolution. Analysis of these data revealed that the crystal belonged to space group C2, with unit-cell parameters a = 158.26, b = 93.04, c = 149.87,Å, , = , = 90, , = 90.65°. The solvent content was 45.85% assuming the presence of six hexameric molecules of the complex in the unit cell. [source]

Preliminary investigation of the three-dimensional structure of Salmonella typhimurium uridine phosphorylase in the crystalline state

ACTA CRYSTALLOGRAPHICA SECTION F (ELECTRONIC), Issue 4 2005
Olga K. Molchan
Uridine phosphorylase (UPh) catalyzes the phosphorolytic cleavage of the C,­N glycosidic bond of uridine to ribose 1-phosphate and uracil in the pyrimidine-salvage pathway. The crystal structure of the Salmonella typhimurium uridine phosphorylase (StUPh) has been determined at 2.5,Å resolution and refined to an R factor of 22.1% and an Rfree of 27.9%. The hexameric StUPh displays 32 point-group symmetry and utilizes both twofold and threefold non-crystallographic axes. A phosphate is bound at the active site and forms hydrogen bonds to Arg91, Arg30, Thr94 and Gly26 of one monomer and Arg48 of an adjacent monomer. The hexameric StUPh model reveals a close structural relationship to Escherichia coli uridine phosphorylase (EcUPh). [source]

Purification, crystallization and preliminary X-ray analysis of uridine phosphorylase from Salmonella typhimurium

ACTA CRYSTALLOGRAPHICA SECTION D, Issue 4 2004
Mariya V. Dontsova
The structural udp gene encoding uridine phosphorylase (UPh) was cloned from the Salmonella typhimurium chromosome and overexpressed in Escherichia coli cells. S. typhimurium UPh (StUPh) was purified to apparent homogeneity and crystallized. The primary structure of StUPh has high homology to the UPh from E. coli, but the enzymes differ substantially in substrate specificity and sensitivity to the polarity of the medium. Single crystals of StUPh were grown using hanging-drop vapor diffusion with PEG 8000 as the precipitant. X-ray diffraction data were collected to 2.9,Å resolution. Preliminary analysis of the diffraction data indicated that the crystal belonged to space group P61(5), with unit-cell parameters a = 92.3, c = 267.5,Å. The solvent content is 37.7% assuming the presence of one StUPh hexamer per asymmetric unit. [source]

Structure of Escherichia coli uridine phosphorylase at 2.0,Å

ACTA CRYSTALLOGRAPHICA SECTION D, Issue 1 2003
F. Temple Burling
The 2.0,Å crystal structure has been determined for Escherichia coli uridine phosphorylase (UP), an essential enzyme in nucleotide biosynthesis that catalyzes the phosphorolytic cleavage of the C,N glycosidic bond of uridine to ribose-1-phosphate and uracil. The structure determination of two independent monomers in the asymmetric unit revealed the residue composition and atomic details of the apo configurations of each active site. The native hexameric UP enzyme was revealed by applying threefold crystallographic symmetry to the contents of the asymmetric unit. The 2.0,Å model reveals a closer structural relationship to other nucleotide phosphorylase enzymes than was previously appreciated. [source]

Preliminary investigation of the three-dimensional structure of Salmonella typhimurium uridine phosphorylase in the crystalline state

ACTA CRYSTALLOGRAPHICA SECTION F (ELECTRONIC), Issue 4 2005
Olga K. Molchan
Uridine phosphorylase (UPh) catalyzes the phosphorolytic cleavage of the C,­N glycosidic bond of uridine to ribose 1-phosphate and uracil in the pyrimidine-salvage pathway. The crystal structure of the Salmonella typhimurium uridine phosphorylase (StUPh) has been determined at 2.5,Å resolution and refined to an R factor of 22.1% and an Rfree of 27.9%. The hexameric StUPh displays 32 point-group symmetry and utilizes both twofold and threefold non-crystallographic axes. A phosphate is bound at the active site and forms hydrogen bonds to Arg91, Arg30, Thr94 and Gly26 of one monomer and Arg48 of an adjacent monomer. The hexameric StUPh model reveals a close structural relationship to Escherichia coli uridine phosphorylase (EcUPh). [source]