Figure 4: Role of the C-terminal region and the HTH motif region of GrlA in GrlR–GrlA interactions.
From: Structure of GrlR–GrlA complex that prevents GrlA activation of virulence genes
(a) The binding affinities of MBP-GrlA/MBP-GrlAΔ to GrlR were determined using ITC. Representative ITC profiles are shown. The GrlA proteins used are indicated above each panel. The upper part of each panel shows the thermogram (thermal power versus time) after baseline correction and the bottom part of each panel shows the binding isotherm (normalized heat versus molar ratio of reactants) for each injection. The solid lines in the bottom part of each panel show the fit of the data to a function based on a single class of binding site model. (b) The binding affinities of GrlR to MBP-GrlA/MBP-GrlAΔ with substitutions in the HTH motif region (5 M) were determined using ITC (5 M refers to substitutions at R53A, R54A, R64A, R65A and K66A). The binding constants (Ka and Kd), number of binding sites (N), enthalpy (ΔH) and entropy (ΔS) are provided in Supplementary Table S1.
