Figure 2

Isothermal titration calorimetric analysis shows binding between the periplasmic domain of ToxR (ToxR-C) and cFP. The change in heat capacity was measured for: (a) purified ToxR-C (0.2 mM) with increasing amounts of cFP, (b) purified ToxR-C (0.2 mM) with increasing amounts of the linear dipeptide phenylalanine-proline, or (c) increasing amounts of cFP in the absence of ToxR-C.