The effect of chemical modification of DNA on its priming activity with RNA polymerase

Abstract

This chapter describes that induced mutations are a result of a number of chemical and enzymic processes in the presence of mutagenic agents and occurring during reproduction and realization of genetic information. For some mutagens, their influence on the cell metabolism, the main chemical reactions with nucleic acid and nucleoprotein components, and the chemical, physical and functional properties of modified residues are known. Comparison of such information with the genetic consequences allows one to elucidate the mechanisms and specificity of basic genetic processes, the structure of genetic macromolecules, and the role of various factors in the selection of mutants. In such investigations, mutagens inducing point mutations have proved to be the most handy tool. Among them, the most feasible are the hydroxylamines, which effectively induce transitions when they attack metabolizing and nonmetabolizing systems. The chapter also emphasizes that the genetic consequences of the action of mutagens vary over a wide range depending on the subject, its functional and physical state and the conditions of mutagenesis. Owing to the abundance of data on the mechanisms of the chemical and enzymic processes induced by hydroxylamines in metabolizing and nonmetabolizing systems and the functional properties of hydroxylamine-modified nucleoside residues, these reagents by right occupy a central position among a multitude of other mutagens and help to elucidate many important problems of molecular biology and molecular genetics.