Biopolymers and cell. 2003; 19 (4): 382 - 385

Is the complementarity of canonical nucleotide bases in DNA their inherent physical-chemical characteristics? Results of the non-empirical quantum-chemical investigation

O. M. Krechkivska, D. A. Kosach, O. O. Sudakov, D. M. Hovorim

Using ab initio Quantum-chemical calculation at the B3LYP/6-31++G(d, p) level in t/ie framework of «hydrophobic scenarios, authors arrived at the conclusion that complementarity of nucleotide hoses in DNA is not their intrinsic property, and their prototropir tautomerism — transition of Gua from keto to enolic form and Cyt — from amino to imino form — is a source of point mutations during the DNA biosynthesis. The obtained sequence of thermo-dynamic stability of quasi-isomorphous pairs GuccCyt > Thy:Gua (enolic) > Ade:Cyt(imino) > Ade:Thy enables us to explain the so-called asymmetry of point mutations in the course of the DNA biosynthesis. This, in its turn, evidences the adequacy of assumptions and conclusions made in this work.