Analysis of Cap0037 binding to the promoter region of the CA_P0037-CA_P0036 operon. (A) EMSAs using the promoter region of the CA_P0037-CA_P0036 operon and Cap0037 protein. Lanes 1 to 6, 0, 0.1, 0.2, 0.3, 0.5, and 0.6 µg protein, respectively; lanes 7 to 10, 0, 0.1, 0.2, and 0.5 µg protein, respectively. (B) DNase I protection assay (DNA footprinting) of Cap0037 interacting with the CA_P0037/CA_P0036 promoter region (probe 85). End-labeled DNA fragment carrying the promoter region of the CA_P0037-CA_P0036 operon was incubated with different concentrations of Cap0037, subjected to DNase I cleavage, and analyzed on a sequencing gel. Sequencing reaction was performed with plasmid pDrive_86kurz. Lanes 1 to 4 contain 0 to 1,438 nM Cap0037. The assigned region on the right side indicates the region protected by Cap0037 and the respective sequence.