Figure 1.

Open pore cryo-EM structure of a hERG construct from Wang and MacKinnon (8). A is a top-down view illustrating the subunit arrangement of the hERG construct membrane domain tetramer. The voltage sensor domain (VSD) (transmembrane helices S1–S4) of one subunit is colored blue. B, side view of the pore domain comprising the S5 helix, pore helix, selectivity filter (SF), and S6 helix; the extracellular turret linking the top of S5 and the N-terminal end of the pore helix has some missing atom density. Amino acid residues mutated in this study or otherwise described in the text are highlighted.