1opr
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THE CRYSTAL STRUCTURE OF THE OROTATE PHOSPHORIBOSYLTRANSFERASE COMPLEXED WITH OROTATE AND ALPHA-D-5-PHOSPHORIBOSYL-1-PYROPHOSPHATE
OverviewOverview
The three-dimensional structure of Salmonella typhimurium orotate, phosphoribosyltransferase (OPRTase) in complex with the ribose 5-phosphate, donor alpha-D-5--phosphoribosyl-1-pyrophosphate (PRPP) and the nitrogenous, base orotic acid has been solved and refined with X-ray diffraction data, extending to 2.3 A resolution to a crystallographic R-factor of 18.7%. The, complex was generated by carrying out catalysis in the crystal. Comparison, of this structure with the previously reported structure of the orotidine, 5'-monophosphate (OMP) complex [Scapin, G., Grubmeyer, C., and, Sacchettini, J. C. (1994) Biochemistry 33, 1287-1294] revealed that the, enzyme backbone undergoes only small movements. The most significant, differences occur near the active site, at Ala71-Gly74, with the largest, difference involving the side chains of Lys73, Val127-Ala133, the, 5'-phosphate binding loop, and a long, solvent-exposed loop at the dimer, interface. The position of the ribose moiety is, on the other hand, very, different in the OMP and PRPP.orotate complexes, with its anomeric carbon, moving approximately 7 A across the binding cavity. In the PRPP.orotate, complex the highly conserved acidic side chain of Asp124 interacts with, the ribose of PRPP, whereas there are no interactions of this aspartate, with the substrate in the OMP complex.
About this StructureAbout this Structure
1OPR is a Single protein structure of sequence from Salmonella typhimurium with MG, ORO and PRP as ligands. Active as Orotate phosphoribosyltransferase, with EC number 2.4.2.10 Full crystallographic information is available from OCA.
ReferenceReference
The crystal structure of the orotate phosphoribosyltransferase complexed with orotate and alpha-D-5-phosphoribosyl-1-pyrophosphate., Scapin G, Ozturk DH, Grubmeyer C, Sacchettini JC, Biochemistry. 1995 Aug 29;34(34):10744-54. PMID:7545004
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