Extended Data Figure 3. EM density maps for the domains whose atomic structural models were generated de novo.

a, The EM density maps for the Handle domain. Representative EM density map for one helix in the Handle domain is shown on the right. b, The EM density maps for the Central domain. Left to right: The EM density maps for the overall domain, the U-motif, and one representative helical repeat in the Central domain, respectively. c-g, The EM density maps for the segments in the channel domain. Shown here are the density maps for the pore forming elements (c), the selectivity filter (d), the luminal hairpin loop (e), the carboxyl terminal domain shown in stereo views (f), and the voltage sensor-like domain (g). The maps, shown as blue mesh, are contoured at 4σ and made in PyMol. Representative bulky residues which were used to aid sequence assignment are shown as sticks and labeled.