Figure 3.

Ternary perturbation affects the pairwise interactions between residues in the interfacial triad. (A) GIA was used to measure the interaction energies between E395-Y485 in the presence of the R394A perturbation. The control or reference channel was the R394A mutant, and the three additional mutants (E, Y, and EY) were obtained in the background of R394A. For each of the four mutants, the normalized Q-V curves are shown along with the thermodynamic cycle in the inset (with each box representing the mutants colored as marked). (B and C) GIA for the R394-Y485 pair in the background of E395A mutation (B) and for the R394-E395 pair in the background of the Y485A mutation (C) showing the respective Q-V curves of the control/reference channel, the two single and the double mutation, and the thermodynamic cycle in the inset. Error bars represent SEM.