[Nucleotide analogs with modified sugar residue, in the RNA synthesis reaction of RNA polymerase from Escherichia coli].

Influence of NTP analogs with the modified sugar residue on RNA synthesis catalyzed by E. coli RNA polymerase was studied. It was shown that analog with ribose residue substituted by hydrocarbon chain (-CH2-)2,3,4 as well as the analogs with opened ribose ring do not incorporate into the RNA chain. These compounds imped RNA elongation (Ki = 1.5--2.0 . 10(-3) M) due to their ability for reversible binding with the enzyme. These analogs inhibit the incorporation of all four natural NTP into RNA to the same extent, independently on the nature of the bases. In contrast, 3'-substituted analogs of NTP compete only with the homologous substrate for incorporation into RNA. The 3'-OMe-NTP incorporate into 3'-end of RNA and stop RNA propagation. The rate of 3'-OMe-NTP incorporation into RNA is 50--100 times lower, than that of the natural substrates.