STRUCTURAL-FUNCTIONAL DYNAMICS OF DNA AND RNA-POLYMERASES

The review deals with the current data on the structure and functions of the enzymes involved in template biocatalysis. Comparative analysis of the three-dimensional structure of different DNA and RNA polymeras es and spatial organization of polymerase domains in the presence and absence of polynucleotide duplexes and (d)NTP has been done. Structura l peculiarities of the polymerase active centers are analyzed. The pre sent-day ideas of the mechanism of multistep reaction of nucleotidyl t ransfer, such as criteria of (d)NTP selection, conformational alterati ons of the enzyme-polynucleotide complex during catalysis, the nucleot idyl transferase reaction, and models of enzyme translocation along th e DNA chain are discussed.