Fig. 7

Activation at the SF in NaK2K and TRAAK channels. a, b Crystal structures of NaK2K (F92A mutant) and TRAAK channels, respectively. Isoleucine residues, equivalent to I84 in MthK, are shown as orange sticks. For the overlay with the MthK structure, see Fig. S12. c, d Outward K+ currents through NaK2K and TRAAK at 300 mV as a function of SF opening at S4, respectively (analogous to Fig. 2 for MthK). In NaK2K, S4 is formed by T63. In TRAAK, which is a dimer, S4 is formed by T129 and T238. Error bars represent 95% confidence intervals. Source data are available as a Source Data file.