[Regulatory properties of RNA polymerase from rifampicin-resistant E. coli strain rpoB403]

Activities of RNA polymerases from wild type B/r strain of E. coli and its pleiotropic rpoB403 rif-r mutant were studied using five various DNA matrices and various groups of early region promotors of T4 and T7 phage DNA. The mutation differentially affects RNA polymerase-catalyzed RNA synthesis depending on the promotor used. Relative efficiency of A3 promotor of T7 phage DNA is enhanced in case of the mutant enzyme. rpoB403 mutation can be used for the classification analysis of promotors differing in their interaction with the enzyme.