FIG. 2.

relA-independent transcriptional upregulation of the indicated genes of the tmRNA-directed peptide tagging and proteolysis system by inhibition of isoleucyl-tRNA synthetase or amino acid deprivation. (A) Northern hybridization of the precursor (pssrA) and processed form (ssrA) of tmRNA from mupirocin-treated (plus) and untreated (minus) control cells. (B) Slot blot hybridizations of RNA extracted from cells incubated in CDM deprived of isoleucine and valine (white columns) and control cells incubated in complete CDM (black columns).