[Role of the beta-subunits of Escherichia coli RNA-polymerase in the regulation of gene activity].

The DNA-dependent RNA-polymerase from E. coli B/r and its rif-r mutant rpoB409 with pleiotropic effect has been studied. It was shown, that multiple forms of promotor sites in T4- and T7-DNA "early" regions are recognized with different efficiences by RNA-polymerases from E. coli B/r and rpoB409. The rif-r rpoB409 mutation has been reported to affect the beta-subunit. Thus, the present data indicates that the selection of promoter sites can be controlled by the beta-subunit of RNA-polymerase.