FIG. 7.

EMSA analysis of wild-type and mutant SarA binding motifs. A 10 pM concentration of ³²P-labeled DNA was incubated with an increasing concentration (twofold increments from 50 to 3,200 pM) of recombinant SarA and resolved by native PAGE. The upper panel illustrates the results obtained with the wild-type agr A1-A2 allele (Table 1). The middle panel illustrates the results obtained with a fragment in which the binding motif was altered in a manner that conserved the overall GC content. The bottom panel illustrates the results obtained with a fragment in which the binding motif was modified in a fashion that increased the overall GC content. WT, wild type.