1q8f
Crystal Structure of the E.coli pyrimidine nucleoside hydrolase yeiK
Structural highlights
FunctionRIHB_ECOLI Hydrolyzes cytidine or uridine to ribose and cytosine or uracil, respectively. Has a clear preference for cytidine over uridine. Strictly specific for ribonucleosides. Has a low but significant activity for the purine nucleoside xanthosine.[HAMAP-Rule:MF_01433] 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 PubMedEnzymes with nucleoside hydrolase (NH) activity are crucial for salvaging nucleic acid components in purine auxotrophic protozoan parasites, but are also present in prokaryotes and higher eukaryotes. Here we analyze the distribution of genes encoding for putative NH proteins and characterize the yeiK gene product from Escherichia coli as a pyrimidine-specific NH. The crystal structure of YeiK to 1.7 A defines the structural basis for its substrate specificity and identifies residues involved in the catalytic mechanism that differ from both nonspecific and purine-specific NHs. Large differences in the tetrameric quaternary structure compared to nonspecific protozoan NHs are brought forth by minor differences in the interacting surfaces. The first structural and functional characterization of a nonparasitic, pyrimidine nucleoside-specific NH suggests a possible role for these enzymes in the metabolism of tRNA nucleosides. The high catalytic efficiency of YeiK toward 5-fluorouridine could be exploited for suicide gene therapy in cancer treatment. Crystal structure to 1.7 a of the Escherichia coli pyrimidine nucleoside hydrolase YeiK, a novel candidate for cancer gene therapy.,Giabbai B, Degano M Structure. 2004 May;12(5):739-49. PMID:15130467[1] From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. References
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