Forces and energetics of the canonical tetrameric cation channel gating.

ABSTRACT: The canonical gating mechanism of tetrameric cation channels involves the spreading of the pore-lining helices at the so-called bundle-crossing gate. Despite a wealth of structural information, we lack a physical description of the gating process. Here, I took advantage of an entropic polymer stretching physical model and MthK structures to derive the forces and energies involved in pore-domain gating. In MthK, the Ca²⁺-induced conformational change in the RCK domain alone opens the bundle-crossing gate through pulling via unfolded linkers. In the open conformation, the linkers serve as entropic springs between the RCK domain and bundle-crossing gate that store an elastic potential energy of 3.6k_BT and exert 9.8 pN (piconewton) radial pulling force to keep the

SUBMITTER: Scheuring S 

PROVIDER: S-EPMC10334803 | biostudies-literature | 2023 Jul

REPOSITORIES: biostudies-literature