FIG. 8.

Binding of wild-type and mutant MBP-FimB fusion proteins to the mutated fimS element. Shown is an electrophoretic mobility shift assay of interactions of lysates containing FimB and its mutant derivatives with a radiolabeled IRL sequence with a 4-bp deletion in the outer half site. The first two lanes are negative controls. SS is the shifted species that corresponds to IRL with one half site occupied by a FimB protomer. UC and P are an unknown complex found in all lanes and the unbound radiolabeled probe, respectively. The IRL DNA fragment was 107 bp.