**4. Conclusions**

Reported results are crucial for understanding the microstructural mechanisms of the spontaneous transitions and transversions, since they allow us to explain, on one side, the origin of the mutagenic tautomers at the separation of the DNA strands before DNA replication and, on the other side, how incorrect purine·pyrimidine, purine·purine and pyrimidine·pyrimidine wobble mispairs adapt to enzymatically competent sizes in the recognition pocket of the highfidelity DNA polymerase.

Obtained results allow us to explain biological experiments available in the literature, which still remain without proper theoretical justification:


These data clarify the nature of genome variability and reveals new facets of the Watson-Crick hypothesis of the spontaneous point mutagenesis arising during DNA replication and significantly expands the possibilities for rational design of chemical mutagens with targeted action, which could be interesting for synthetic biology and biotechnology.

Finally, authors believe that these principles could be extended without any constrains to the processes determining the protein synthesis.

In view of the prominent role, that play parallel and antiparallel Hoogsteen pairings in DNA:RNA helices, as it was reliably established by Prof. Seligmann [95, 96] for mitochondrial genomes, it is important to explore in future mutagenic tautomerization of these classical base pairs by the quantum-chemical methods.
