Fig 6.

The citZ transcript is stabilized by a citB null mutation. Wild-type (168) and citB null (GP1441) cells were grown in CSE minimal medium. Rifampin (final concentration, 100 mg/ml) was added to logarithmically growing cultures, and samples were taken at the indicated time points after treatment. RNA was isolated and analyzed by Northern blotting using a probe specific to the citZ sense strand. The citB null RNA blot was exposed for a shorter time period than the wild-type blot to accommodate the differences in RNA levels between the strains.