FIG. 1.

Voltage-gated K⁺ channels. (A) Structure of a Kv1.2/Kv2.1 chimeric channel according to Long et al. (74) (KCNA2/KCNB1; PDB 2R9R) with docked Kvβ2 subunits. (B) Structural elements covering S1–S6 of a single subunit of the Kv1.2/2.1 chimera. Two K⁺ ions at the selectivity filter are also indicated. (C) Topological model of a 6TM α-subunit of voltage-gated K⁺ channels illustrating the voltage-sensor domain (S1–S4), the pore/gate domain (S5–S6), and an N-terminal domain that functions in some channel types as inactivation “ball” domain. 6TM, six transmembrane segments. To see this illustration in color, the reader is referred to the web version of this article at www.liebertpub.com/ars