FIGURE 6.
Stability of pnp and glnS transcripts upon S1 depletion. Bacterial cultures of C-5698 and C-5707 were grown up to OD600 = 0.2, diluted 1:4 in permissive (ara) or nonpermissive (glu) conditions, and further incubated until OD600 = 0.2 was reached. After an additional 60 min incubation, rifampicin (final concentration of 0.4 mg/mL) and nalidixic acid (0.03 mg/mL) were added and samples for RNA extraction were then taken at different time points (indicated above the lanes) after antibiotic addition. Twelve micrograms of RNA were run on 1.5% denaturing agarose gel, blotted onto a nylon sheet, and analyzed by Northern blotting to reveal pnp (upper part) or glnS (lower part) mRNA. Length of pnp transcripts (in kilobases) is reported on the right of the panels.