Figure 2. Effects of ryhB, fur, rne701 and hfq mutations on msrB transcript stability.

msrB transcript stability in wild type (A), ryhB mutant (B), fur mutant (C), hfq mutant (D) and rne701 mutant (E) strains grown at 37°C to an O.D.₆₀₀ of 0.4, was assayed by Northern blot analysis. After 10 min of incubation with 2,2′dip, rifampicin was added. Samples were removed at the indicated time points after rifampicin addition and total RNA was extracted as described in Materials and Methods. For determination of msrB mRNA amount, 10 μg of total RNA samples were loaded onto a denaturating agarose gel. After migration, a Northern blot hybridization was performed with a specific oligoprobe for msrB and 5S as an internal control. Band intensity of msrB transcript was normalized to that of 5S RNA. Half-life (seconds) of msrB transcript and the ratio of msrB mRNA half-life ±2,2′dip are indicated for the different strains. Standard errors (SE) are shown.