Gating interaction maps reveal a noncanonical electromechanical coupling mode in the Shaker K⁺ channel.

ABSTRACT: Membrane potential regulates the activity of voltage-dependent ion channels via specialized voltage-sensing modules, but the mechanisms involved in coupling voltage-sensor movement to pore opening remain unclear owing to a lack of resting state structures and robust methods to identify allosteric pathways. Here, using a newly developed interaction-energy analysis, we probe the interfaces of the voltage-sensing and pore modules in the Drosophila Shaker K⁺ channel. Our measurements reveal unexpectedly strong equilibrium gating interactions between contacts at the S4 and S5 helices in addition to those between S6 and the S4-S5 linker. Network analysis of MD trajectories shows that the voltage-sensor and pore motions are linked by two distinct pathways: a canonical pathway through t

SUBMITTER: Fernandez-Marino AI 

PROVIDER: S-EPMC6170002 | biostudies-literature | 2018 Apr

REPOSITORIES: biostudies-literature