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ISSN 2071-0186   Ukr. J. Phys. 2015, Vol. 60, N 8, p.748-756
doi:10.15407/ujpe60.08.0748    Paper

Brovarets O.O.1,2, Hovorun D.M.1,2

1 Institute of Molecular Biology and Genetics, Nat. Acad. of Sci. of Ukraine
(150, Academician Zabolotnyi Str., Kyiv 03680, Ukraine; e-mail: dhovorun@imbg.org.ua)
2 Institute of High Technologies, Taras Shevchenko National University of Kyiv
(2h, Academician Glushkov Ave., Kyiv 03022, Ukraine)

How Do Long Improper Purine-Purine Pairs of DNA Bases Adapt The Enzymatycally Competent Conformation? Structural Mechanism And Its Quantum-Mechanical Grounds

Section: Soft matter
Language: English

Abstract: Aimed at the answer the biophysically important question posed in the title of this article, we have first investigated, at the MP2/aug-cc-pVDZ//B3LYP/6–311++G(d,p) level of quantummechanical theory, the structural, energetic, and dynamic features of the acquisition of the enzymatically competent conformation by the incorrect А*·А(WC), G·A(WC), A*·G*(WC), and G*·G(WC) DNA base mispairs with the Watson–Crick (WC) geometry – active players on the field of spontaneous point mutagenesis. It is first shown that the characteristic time of these non-dissociative A*·A(WC)-A*·Asyn(TF), G·A(WC)-G·Asyn, A*·G*(WC)-A*·G* syn, and G·G*(WC)-G·G* syn conformational transitions is much less than the period of time that it is spent by a high-fidelity DNA-polymerase on the incorporation of one nucleotide into the DNA double helix.

Key words: DNA biosynthesis, spontaneous transversion, large-amplitude rearrangement, conformational transition, Watson–Crick-like mispair, purine-purine DNA mismatch, MP2 and B3LYP, QTAIM.