FIG. 3.

Binding of purified recombinant Irr to ICE-like DNA sequences from ferric siderophore receptor gene promoters. EMSA analysis was carried out with 200 nM purified Irr and 0.1 nM radiolabeled DNA probes. The DNA probes are 42 bp in size and include 21-bp ICE-like sequences corresponding to that found in the upstream region of each gene. Each DNA was incubated either without protein (F) or with Irr (I). Complexes were resolved on 6% nondenaturing gels and visualized by autoradiography.