Main-chain mutagenesis reveals intrahelical coupling in an ion channel voltage-sensor.

ABSTRACT: Membrane proteins are universal signal decoders. The helical transmembrane segments of these proteins play central roles in sensory transduction, yet the mechanistic contributions of secondary structure remain unresolved. To investigate the role of main-chain hydrogen bonding on transmembrane function, we encoded amide-to-ester substitutions at sites throughout the S4 voltage-sensing segment of Shaker potassium channels, a region that undergoes rapid, voltage-driven movement during channel gating. Functional measurements of ester-harboring channels highlight a transitional region between α-helical and 3₁₀ segments where hydrogen bond removal is particularly disruptive to voltage-gating. Simulations of an active voltage sensor reveal that this region features a dynamic hydrogen b

SUBMITTER: Infield DT 

PROVIDER: S-EPMC6265297 | biostudies-literature | 2018 Nov

REPOSITORIES: biostudies-literature