VIOMYCIN RESISTANCE - ALTERATIONS OF EITHER RIBOSOMAL-SUBUNIT AFFECT THE BINDING OF THE ANTIBIOTIC TO THE PAIR SUBUNIT AND THE ENTIRE RIBOSOME BECOMES RESISTANT TO THE DRUG

Viomycin inhibited polypeptide synthesis and translocation of peptidyl-tRNA on ribosomes derived from a sensitive strain of M. smegmatis (R-15), but not significantly on ribosomes from viomycin-resistant mutants (R-31 and R-43). The binding of [14C]tuberactinomycin O, a viomycin analog, to ribosomal particles was studied by Millipore filter method. The sensitive ribosome exhibited higher affinity for the antibiotic than the resistant ribosomes. The resistance was localized on the large ribosomal subunit in a mutant (R-31), and on the small subunit in another mutant (R-43). The binding of the drug to the sensitive ribosomal subunit was markedly reduced by combination with the resistant pair subunit, and the entire ribosome became resistant to the antibiotic. © 1979.