Figure 6.

Model for the interaction between Idr1 and Idr2 in the control of gene expression in response to iron. The model depicts a gene regulatory network under the control of Idr1 and Idr2 based on the data presented in this study. Arrows represent activation influences, whereas blunt-headed lines represent repression. The circles represent Idr1 and Idr2 (TFs). Hexagons depict the clusters of genes under shared control of Idr1 and Idr2. Numbers of the clusters correspond with those shown in Figure 5A. Rectangles depict genes involved in iron homeostasis that are independently controlled by either Idr1 (fhuG/yfmF, genes encoding the hydroxamate siderophore uptake system; hem, siroheme biosynthesis gene cluster) or Idr2 (iucABC, genes encoding a different siderophore uptake system; dmsDABCE, DMSO reductase-coding operon).