Figure 3

Repression kinetics defining the window of transcriptional regulation for specified FeHm-regulated genes in strain Hib 10810. (A) Fold changes in expression of hitA in isolate Hib 10810 over the course of 150 minutes of growth under three different sets of conditions. Strain Hib 10810 was grown in either: 1) medium that was restricted for iron and heme for the duration of the experiment (open circles), 2) medium that was fully supplemented with iron and heme for the duration of the experiment (closed circles) or 3) medium that was restricted for iron and heme up to 90 minutes at which point iron and heme were added to fully supplement the medium (closed squares). (B) Fraction of transcript level remaining relative to the transcript level seen at the 90 minute timepoint in panel A. Results are shown for transcript levels of: hitA in medium fully supplemented with iron and heme for the duration of the experiment (open squares); hitA in medium that was restricted for iron and heme up to 90 minutes at which point iron and heme were added to fully supplement the medium (closed squares); tbp1 in medium fully supplemented with iron and heme for the duration of the experiment (open circles); tbp1 in medium that was restricted for iron and heme up to 90 minutes at which point iron and heme were added to fully supplement the medium (closed circles); hxuC in medium fully supplemented with iron and heme for the duration of the experiment (open triangles); hxuC in medium that was restricted for iron and heme up to 90 minutes at which point iron and heme were added to fully supplement the medium (closed triangles).