Extended Data Fig. 8: Single-particle cryo-EM characterization of the gating-ring structures in the MthK Ca²⁺ dataset.

a, Final cryo-EM map of RCK state 1 coloured by local resolution. b, FSC curves between the two independently refined half-maps of MthK Ca²⁺ RCK state 1 (black), and from cross validation between the atomic model refined against the final cryo-EM map (red). c, Angular distribution of particles used in the reconstitution of RCK state 1. d, Final cryo-EM map of RCK state 2 coloured by local resolution. e, FSC curves between the two independently refined half-maps of MthK Ca²⁺ RCK state 2 (black), and from cross validation between the atomic model refined against the final cryo-EM map (red). f, Angular distribution of particles used in the reconstitution of RCK state 2. g, Segmented cryo-EM density maps (grey mesh) of RCK state 2. The fitted corresponding atomic model is in cyan.