Biopolymers and cell. 2005; 21 (6): 559 - 561

Mechanism of 6-azacytosine N1-glycosides interaction with catalytic site of phage T7 DNA-dependent RNA-polymerase: model quantum-chemical study

L. H. Palchikovska, M. O. Platonov, I. V. Alexeeva, A. D. Shved

By the quantum-chemistry approach at the HF/6-31G (d, p) theory level for the first time considerable increase in the charge value of the atom N6 of azanucleosides in the model of catalytic site of phage T7 DNA-dependent RNA-polymerase was recorded. The blocking of Mg²⁺ ion by the additional interaction with N6 atom in the azanucleoside─metal─Tyr639 complex seems to reduce the rate of elongation, that was confirmed experimentally by the significant decrease in the amount of synthesized RNA in a unit of time.

Key words: phage T7 DNA-dependent RNA polymerase, azanucleosides, 6-azacytosine N1-glycosides.