Substrate specificity of uridine and purine nucleoside phosphorylases of the whole cells of Escherichia coli
Zintchenko, A.I.; Eroshevskaya, L.A.; Barai, V.N.; Mikhailopulo, I.A.
Nucleic Acids Symposium Series 18: 137-140
1987
ISSN/ISBN: 0261-3166 PMID: 3122186 Document Number: 297688
Substrate specificity of uridine and purine nucleoside phosphorylases of the whole cells of Escherichia coli BM-11 has been studied. Both enzymes reveal similar requirements to the structure and stereochemistry of uracil nucleosides and of the pentofuranose-1-phosphates, respectively, viz, a) modifications at C-3' decreased the substrate activity to a greater extent as compared with the same modifications at C-2'; b) substitution of a methyl group for one of the 5'-CH2 protons does not lead to essential alterations of the substrate activity of such analogs vs. the natural substrates - uridine and ribofuranose-1-phosphate, respectively. PNP exhibits a very broad specificity for the purine acceptor.