title: Atomic structure at 2.5 A resolution of uridine phosphorylase from E. coli as refined in the monoclinic crystal lattice.
abstract: Uridine phosphorylase from E. coli (Upase) has been crystallized using vapor diffusion technique in a new monoclinic crystal form. The structure was determined by the molecular replacement method at 2.5 A resolution. The coordinates of the trigonal crystal form were used as a starting model and the refinement by the program XPLOR led to the R-factor of 18.6%. The amino acid fold of the protein was found to be the same as that in the trigonal crystals. The positions of flexible regions were refined. The conclusion about the involvement in the active site is in good agreement with the results of the biochemical experiments.
authors.affiliation: Institute of Crystallography of Russian Academy of Sciences, Moscow.
authors.lastname: Morgunova EYu
authors.forename: A M
authors.initials: AM
authors.lastname: Mikhailov
authors.forename: A N
authors.initials: AN
authors.lastname: Popov
authors.forename: E V
authors.initials: EV
authors.lastname: Blagova
authors.forename: E A
authors.initials: EA
authors.lastname: Smirnova
authors.forename: B K
authors.initials: BK
authors.lastname: Vainshtein
authors.forename: C
authors.initials: C
authors.lastname: Mao
authors.forename: Sh R
authors.initials: ShR
authors.lastname: Armstrong
authors.forename: S E
authors.initials: SE
authors.lastname: Ealick
authors.forename: A A
authors.initials: AA
authors.lastname: Komissarov
mesh_terms: D000595:Amino Acid Sequence; D001665:Binding Sites; D018360:Crystallography, X-Ray; D004926:Escherichia coli / Q000201:enzymology*; D006860:Hydrogen Bonding; D008958:Models, Molecular; D008969:Molecular Sequence Data; D011487:Protein Conformation; D017433:Protein Structure, Secondary; D014543:Uridine Phosphorylase / Q000737:chemistry*
chemical_list: D014543:Uridine Phosphorylase