Figure 1

Geometrical structures of the stationary points on the reaction pathways of the discovered conformational transitions of the four biologically important А·Т DNA bps. Electronic energies of the interaction ΔE_int (MP2/6-311++G(2df,pd)//B3LYP/6-311++G(d,p) level of theory, in kcal∙mol⁻¹), relative Gibbs free energies ∆G and electronic energies ∆E (in kcal∙mol⁻¹), imaginary frequencies ν_i at the TSs of the conformational transitions (MP2/aug-cc-pVDZ//B3LYP/6-311++G(d,p) level of theory in the continuum with ε = 4 at T = 298.15 К) are presented below complexes in brackets. Dotted lines indicate AH···B H-bonds and attractive A···B van der Waals contacts – their lengths are presented in angstroms (for their more detailed physico-chemical characteristics see Table 2); carbon atoms are in light-blue, nitrogen – in dark-blue, hydrogen – in grey and oxygen – in red. Exclusively enantiomers of one type are presented.