FIG. 2.

Binding of GbpA, B-GBD, and GBD-SKC to various concentrations of dextran in the gel retardation assay. Purified proteins or cellular lysates containing the protein of interest were run on native gels containing different amounts of dextran (molecular weight, 500,000). Proteins were blotted onto nitrocellulose and stained with an anti-GBD antibody. RU were calculated as described in the text. Asterisks indicate that the migration of GBD-SKC was reduced significantly compared to those of both GbpA and B-GBD, based on a Student t test (P, <0.01). The migration of GbpA and that of B-GBD did not differ statistically, except at a dextran concentration of 10 mg/liter. Error bars show standard deviations.