FIGURE 3.

Expression levels of fetMP depend on iron availability. E. coli strains ECA612 (glmS-fetMP) (●) and negative control ECA611 (glmS-Gm) (○) were cultivated in TMM (pH 7) without added iron at 37 °C with shaking. After 5 min of incubation, 100 μm FeCl₃ was added (black arrow). At the 25 min time point, the cultures were divided, and 200 μm CDTA was added to one set of cultures (open arrow, ●), whereas no addition was made to the other set (■). The cells were harvested at various time points, and the fetP mRNA content was determined using the sandwich hybridization technique. The inset indicates the mRNA levels of fetMP-containing cells after the addition of 200 μm CDTA. Averages of three independent experiments with S.D. values (error bars) are shown.