Fig. 4
Binding kinetics of XreR2 and XreR1 to different promoter regions. Binding kinetics were determined using SPR spectroscopy. The three promoters PxreR2, PxreR1 and PpTAS were immobilized onto a SA sensor chip and various concentrations of XreR1 (1 nM, 2.5 nM, 5 nM, 10 nM, 25 nM, and 50 nM), XreR2 (100 nM, 250 nM, 500 nM, 1000 nM, 2500 nM) or a 50:50 mixture of both XreR1 and XreR2 (1 nM, 2.5 nM, 5 nM, 10 nM, 25 nM, 50 nM, 100 nM, 250 nM, 500 nM, 1000 nM), respectively, were injected. For better comparability to the sensorgrams using solely XreR1 and XreR2, both sensorgrams using lower and higher XreR1:XreR2 concentrations are shown. All sensorgrams represent one characteristic of three independently performed experiments. n.b. = no binding; n.q. = not quantifiable