FIG. 4.

Footprinting analysis of purified Fur on the NMB204-fur intergenic probe. The probe was labeled at one extremity and prepared as described in Materials and Methods. Lanes 2 to 7 contain reaction mixtures to which purified Fur protein at 13.4 nM, 40 nM, 122 nM, 366 nM, 1.1 μM, and 3.2 μM, respectively, was added. Lane 1 represents the G+A sequence reaction (19) obtained with the same probe and used as a molecular weight marker. The solid arrow shows the position and the orientation of the fur coding region. The dashed arrow indicates the orientation of the smpA gene, which is not contained in the probe.