Binding of recombinant SO2426 proteins to putative recognition site. Electrophoretic mobility shift assays were performed to demonstrate binding of recombinant SO2426 (A) and SO2426sh (B) to the predicted SO2426 recognition motif upstream of the so3030-3031-3032 operon. Lanes: 1, DNA template only; 2, vector-only control E. coli cell lysate (15 μg); 3-7, increasing concentrations of either recombinant SO2426 or SO2426sh ranging from 0.6 to 3.0 μg in 0.6 μg increments. Each reaction mixture contained 95 ng of DIG-labeled DNA template. No binding was seen with an excess of vector-only control cell lysates (lane 2); whereas, a clear shift is seen with increasing amounts of either recombinant SO2426 or SO2426sh.