Substrate specificity of uridine and purine nucleoside phosphorylases of the whole cells of Escherichia coli.
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.
D000241:Adenosine / Q000031:analogs & derivatives*; D004926:Escherichia coli / Q000201:enzymology*; D010430:Pentosyltransferases / Q000378:metabolism*; D011683:Purine-Nucleoside Phosphorylase / Q000378:metabolism*; D013379:Substrate Specificity; D014529:Uridine / Q000031:analogs & derivatives*; D014543:Uridine Phosphorylase / Q000378:metabolism*
D010430:Pentosyltransferases; D011683:Purine-Nucleoside Phosphorylase; D014543:Uridine Phosphorylase; D000241:Adenosine; D014529:Uridine