1OPR

THE CRYSTAL STRUCTURE OF THE OROTATE PHOSPHORIBOSYLTRANSFERASE COMPLEXED WITH OROTATE AND ALPHA-D-5-PHOSPHORIBOSYL-1-PYROPHOSPHATE

Summary for 1OPR

• Entry DOI: 10.2210/pdb1opr/pdb
• Descriptor: OROTATE PHOSPHORIBOSYLTRANSFERASE, MAGNESIUM ION, OROTIC ACID, ... (5 entities in total)
• Functional Keywords: transferase
• Biological source: Salmonella typhimurium
• Total number of polymer chains: 1
• Total formula weight: 24162.44

Authors

Scapin, G.,Sacchettini, J.C. (deposition date: 1995-01-06, release date: 1996-01-06, Last modification date: 2024-02-14)

Primary citation

Scapin, G.,Ozturk, D.H.,Grubmeyer, C.,Sacchettini, J.C.
The crystal structure of the orotate phosphoribosyltransferase complexed with orotate and alpha-D-5-phosphoribosyl-1-pyrophosphate.
Biochemistry, 34:10744-10754, 1995

PubMed Abstract: 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.

PubMed: 7545004
DOI: 10.1021/bi00034a006

Experimental method

X-RAY DIFFRACTION (2.3 Å)