SOME ASPECTS OF PROTEIN-DNA RECOGNITION IN TRANSCRIPTION INITIATION

The temperature-dependent conformational transitions of E. coil RNA po lymerase complexes with the bacteriophage T7 D promoter were studied. The topology of two types of conformers was assessed by DNase I footpr inting. Enzymatic testing of the promoter structure revealed structura l changes in the temperature range considered. The data obtained testi fy that the physicochemical properties of the promoter DNA may be the basis of the structural-conformational rearrangements in the transcrip tional complex and, therefore, be important for the differentiated reg ulation of gene activity.