Ribonucleic Acid Synthesis in Chloramphenicol-treated Shigella

Abstract

CHLORAMPHENICOL markedly inhibits protein synthesis by bacteria. The organisms, however, continue to produce ribonucleic acid (RNA) at an unaltered rate or at one higher than that of cells not under the influence of the drug^1,2. Several groups of investigators have examined extracts of chloramphenicol-treated Escherichia coli to determine the cellular fraction in which the newly formed RNA was located. Pardee et al.³ concluded from their findings that the RNA was either of a low molecular weight or was easily degraded during extraction from the cells. The latter explanation appears likely since the authors did not extract the RNA with a medium containing magnesium ions to minimize the breakdown of ribosomal particles. Using such a medium, Dagley and Sykes⁴ and Nomura and Watson⁵ detected the appearance of a new ribosomal component in the extracts of treated cells. The latter investigators also noted that soluble or low-molecular-weight RNA continued to be synthesized in the presence of the antibiotic.