1u1c
Structure of E. coli uridine phosphorylase complexed to 5-benzylacyclouridine (BAU)Structure of E. coli uridine phosphorylase complexed to 5-benzylacyclouridine (BAU)
Structural highlights
Function[UDP_ECOLI] Catalyzes the reversible phosphorylytic cleavage of uridine and deoxyuridine to uracil and ribose- or deoxyribose-1-phosphate. The produced molecules are then utilized as carbon and energy sources or in the rescue of pyrimidine bases for nucleotide synthesis. Evolutionary Conservation Check, as determined by ConSurfDB. You may read the explanation of the method and the full data available from ConSurf. Publication Abstract from PubMedUridine phosphorylase (UP) catalyzes the reversible phosphorolysis of uridine to uracil and ribose 1-phosphate and is a key enzyme in the pyrimidine-salvage pathway. Escherichia coli UP is structurally homologous to E. coli purine nucleoside phosphorylase and other members of the type I family of nucleoside phosphorylases. The structures of 5-benzylacyclouridine, 5-phenylthioacyclouridine, 5-phenylselenenylacyclouridine, 5-m-benzyloxybenzyl acyclouridine and 5-m-benzyloxybenzyl barbituric acid acyclonucleoside bound to the active site of E. coli UP have been determined, with resolutions ranging from 1.95 to 2.3 A. For all five complexes the acyclo sugar moiety binds to the active site in a conformation that mimics the ribose ring of the natural substrates. Surprisingly, the terminal hydroxyl group occupies the position of the nonessential 5'-hydroxyl substituent of the substrate rather than the 3'-hydroxyl group, which is normally required for catalytic activity. Until recently, inhibitors of UP were designed with limited structural knowledge of the active-site residues. These structures explain the basis of inhibition for this series of acyclouridine analogs and suggest possible additional avenues for future drug-design efforts. Furthermore, the studies can be extended to design inhibitors of human UP, for which no X-ray structure is available. Structural basis for inhibition of Escherichia coli uridine phosphorylase by 5-substituted acyclouridines.,Bu W, Settembre EC, el Kouni MH, Ealick SE Acta Crystallogr D Biol Crystallogr. 2005 Jul;61(Pt 7):863-72. Epub 2005, Jun 24. PMID:15983408[1] From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. See AlsoReferences
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