Fig 3.

Stability of csrB and csrC in WT (A) and nhaR mutant (B) of E. coli MG1655, grown for 18 h at 26°C in LB pH 8.4 TAPS. RNA synthesis was inhibited by rifampicin (300μg/ml) and RNA was isolated at different time points after inhibition. Fraction of remaining RNA at each time point is shown. The 16S and 23S rRNA were stained with methylene blue and served as an internal control. The RNA half-lives were determined from the linear portions of the decay curves (C). The CsrB half-life in isogenic MG1655 (wild type) and nhaR mutant strains was 5 and 13 min., respectively. The CsrC half-life in the same strains was 7 and 22 min., respectively.