DEGRADATION OF RIBOSOMAL-RNA IN SALMONELLA STRAINS - A NOVEL MECHANISM TO REGULATE THE CONCENTRATIONS OF RIBOSOMAL-RNA AND RIBOSOMES

We have previously shown that the 23S rRNA of Salmonella strains is hi ghly fragmented by specific enzyme cleavages. In this article, we repo rt that 23S rRNA of Salmonella strains is rapidly degraded as the cell s enter the stationary phase. More than 90% of the 23S rRNA is degrade d when the cells reach the stationary phase. The rate of degradation o f 23S rRNA correlated with its degree of fragmentation, This degradati on is probably mediated by newly synthesized protein factor(s), since treatment with chloramphenicol or rifampin inhibits the rRNA degradati on, We propose that degradation of 23S rRNA is a novel mechanism in th e regulation of the bacterial 23S rRNA and ribosome concentration and that this additional regulatory mechanism provides some selective adva ntage to cells.