Figure 6.

The F656-F557 stacking interaction between the aromatic rings is dominant in the M651T-hERG1 but not in the WT-hERG1. (A–D) Comparisons of time traces for F656 χ₁ and F556–F656 C-C distances for the M651T-hERG1 (A, B, respectively) and the WT-hERG1 are shown (C, D, respectively). The time traces are averaged over all four monomers. The C-C distances corresponds to the distance between the two aromatic ring centers in F656 and F557. Dashed red line is at ~8 Å for ring-to-ring C-C distance corresponds to the state with F656 bent towards the water-filled intra-cellular cavity and T-shaped interaction between F656 and F557 is destabilized.