Authors : M. BELJANSKI, P. BOURGAREL, M.S. BELJANSKI
Annales Institut Pasteur, 1970, 118, pp. 253-276
Available in French only
Summary in English
ABSTRACT: Showdomycin, even at concentrations which do not affect bacterial growth, causes in E. coli, B. cereux and A. faecalis, a massive biosynthesis of rapidly labelled RNAs, which are no longer complementary to DNA. In addition in E. coli, the more thoroughly investigated organism, even non-inhibitory concentrations of the antibiotic provoke the synthesis of ribosomal 23 S RNA with a base ratio very different (excess of A and G nucleotides), from that of 16 S RNA and 4 S RNA. A similar change in RNA composition is observed in a showdomycin resistant mutant of E. coli, the growth rate of which is not lower than that of the wild type. RNA polymerase DNA dependent from the mutant has a very reduced specific activity; polynucleotide phosphorylase from the same mutant has new properties. Polynucleotide phosphorylase could in vivo be responsible for the synthesis of the modified RNAs.