Superposition of voltage sensor and S1–S4 domains. (A) Stereoscopic view of a superposed voltage sensor domain from the Kv2.1-chimeric channel (blue) with the S1–S4 domain from the MlotiK1 channel (magenta). (B) Stereoscopic view of superposed voltage sensor domains from the Kv2.1-chimeric channel (blue) and from the KvAP channel (green). Domains were manually superposed by overlapping S1 and S2 from the different structures. (C) Comparison between the S4 of all three channels using the color code defined in A and B. α-Helical segments are shown as a thin helical trace, and 3₁₀ sections are shown as a thick ribbon. Surface representation corresponds to S1, S2, and S3 from the Kv2.1-chimeric channel.