FIG. 5.

rpoS mRNA and RpoS levels in a Δrnc mutant strain in the presence and absence of DsrA. CM1000 (rnc⁺ rne wild type), CM1010 [rnc⁺ rne(Ts)], CM1050 (Δrnc-1223::cat rne wild type), and CM1052 [Δrnc-1223::cat rne(Ts)] with the pNM12 vector or pBAD-dsrA were grown at 30°C in LB Ap to mid-exponential phase; sRNA expression was induced with 0.02% arabinose for 20 min. Samples were collected for protein and RNA isolation, as described in Materials and Methods (O.D.₆₀₀, optical density at 600 nm). (A) Northern blot analysis of RNA samples was performed using the oligonucleotide probe RpoS-N3 to detect rpoS mRNA. (B) Western blot analysis of protein samples was performed using the anti-RpoS antibody to detect RpoS. Graphical analyses show the mean accumulation of the full-length rpoS mRNA or RpoS protein ± the standard deviation (n = 3) relative to that of CM1000 with the vector control. Samples were also tested by Western blotting for EF-Tu, which was close to identical in each sample. Values over the bars indicate the mean fold change.