INTERPRETATION OF HOT SPOTS OF ULTRAVOLETIC MUTAGENESIS FORMED ON A LAGGING STRAND OF DOUBLE-STRANDED DNA OF THE supF GENE

Abstract

At present, the mechanism of formation of hot and cold spots of ultraviolet mutagenesis is not clear. I developed a polymerase-tautomeric model of the mechanism of formation of hot and cold spots of ultraviolet mutagenesis and showed that the probability of mutation formation depends on the processes of propagation of excitation energy along the DNA molecule. In my proposed polymerase-tautomeric model of ultraviolet mutagenesis, it was shown that mutations are formed opposite only those cis-syn cyclobutane pyrimidine dimers, one or both of which are in rare tautomeric forms. In the polymerase-tautomeric model of the mechanism of formation of hot and cold spots of ultraviolet mutagenesis, I have shown that the hot spots of ultraviolet mutagenesis are those cis-syn cyclobutane pyrimidine dimers to which the most excitation energy is transferred. In a number of works, I calculated the relative probabilities of mutations formed opposite the DNA bases that are part of the cis-syn cyclobutane pyrimidine dimers that appeared upon irradiation of double-stranded DNA of the supF gene. In this article, based on the results of previous calculations, I interpret experimental data in which hot spots of ultraviolet mutagenesis are DNA regions consisting of three or more pyrimidine DNA bases arranged in a row.