[Kinetic determination of the non-specific constants for the binding of Escherichia coli RNA polymerase to T7 phage DNA].

The kinetics of promoter complex formation of E. coli RNA polymerase with T7 phage DNA was studied under different ionic strengths at DNA concentrations 0.15, 1.5 and 20 microns/ml. Based on the results obtained the non-specific binding constants, Keq, and the promoter complex formation rate constants, kp, were estimated. Within ionic strength range 0 + 125 mM NaCl the Keq and kp vary from 5.10(6) to 9.10(5) M-1 and from 0.8 x 0.26 x 10(9) M-1 S-1, respectively. The results are discussed from the view point of the one-dimensional diffusion sliding of the enzyme along DNA in the process of phomoter site selection.