Figure 1.

Topology and structure of the S4-S5 linker and S6 segment in the K-Shaw2 channel, with the Ala/Val scan region highlighted in gray in B and C. (A) Sequences of the S4-S5 linker and S6 segment (mutated residues shown in bold). A lowercase “n” above the sequence indicates nonexpressing mutants; numbers indicate the number of the final residue in each segment. (B) K-Shaw2 exhibits classical Kv channel membrane topology with six TM segments and intracellular termini. The first four membrane-spanning segments form the voltage sensor, and the last two segments form the pore domain. (C) Structural model of the S4-S5 linker and the S6 segment of K-Shaw2. The inset depicts a tetrameric model of the K-Shaw2 pore domain, including the S4-S5 linkers. This homology model was created by MD simulation (Supporting Material).