Fig 1. In vitro interaction of PsaR-Strep tag with the promoter regions of pcpA (A), psaB (B), prtA (C), and phtB (D).

PsaR-Strep was added at concentration of 30 nM as indicated above panel, while lane 1 is without added protein. Arrows indicate the position of shifted probe and asterisks indicate the position of free probe. Mn²⁺ was added with concentrations of 0.05 mM in lanes 3, 7, and 9, and 0.1 mM in lane 4, 8, and 10. Ni²⁺ was added with concentrations of 0.2 mM in lanes 5, 7, and 9, and 0.4 mM in lanes 6, 8, and 10.