A link between streptomycin and rifampicin mutation.

Introduction of str A mutations frequently make "male" strains of Escherichia coli permissive to bacteriophage T7; certain rif mutations reverse the permissive effect of strA mutation. Permissiveness of the strA mutation is accompanied by enhanced transcription of bacteriophage T7 genome. Introduction of the nonpermissive rif allele to the permissive strA strain reduces or abolishes the transcription of T7 genome. Thus, a link is implied in the functioning of the ribosome and the RNA polymerase (RNA nucleotidyltransferase, EC 2.7.7.6).