title: Preliminary investigation of the three-dimensional structure of Salmonella typhimurium uridine phosphorylase in the crystalline state.
abstract: 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 A 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).
authors.affiliation: Institute of Protein Research, Russian Academy of Sciences, Pushchino, Russia.
authors.forename: Maria V
authors.initials: MV
authors.lastname: Dontsova
authors.forename: Azat G
authors.initials: AG
authors.lastname: Gabdoulkhakov
authors.forename: Olga K
authors.initials: OK
authors.lastname: Molchan
authors.forename: Alexandr A
authors.initials: AA
authors.lastname: Lashkov
authors.forename: Maria B
authors.initials: MB
authors.lastname: Garber
authors.forename: Alexandr S
authors.initials: AS
authors.lastname: Mironov
authors.forename: Nadegda E
authors.initials: NE
authors.lastname: Zhukhlistova
authors.forename: Ekaterina Yu
authors.initials: EY
authors.lastname: Morgunova
authors.forename: Wolfgang
authors.initials: W
authors.lastname: Voelter
authors.forename: Christian
authors.initials: C
authors.lastname: Betzel
authors.forename: Yang
authors.initials: Y
authors.lastname: Zhang
authors.forename: Steven E
authors.initials: SE
authors.lastname: Ealick
authors.forename: Al'bert M
authors.initials: AM
authors.lastname: Mikhailov
mesh_terms: D001665:Binding Sites; D018360:Crystallography, X-Ray; D004926:Escherichia coli / Q000201:enzymology; D006860:Hydrogen Bonding; D015394:Molecular Structure; D011487:Protein Conformation; D012486:Salmonella typhimurium / Q000201:enzymology*; D014543:Uridine Phosphorylase / Q000737:chemistry*
chemical_list: D014543:Uridine Phosphorylase