Dimerization mechanism of an inverted-topology ion channel in membranes.

ABSTRACT: Many ion channels are multisubunit complexes where oligomerization is an obligatory requirement for function as the binding axis forms the charged permeation pathway. However, the mechanisms of in-membrane assembly of thermodynamically stable channels are largely unknown. Here, we demonstrate a key advance by reporting the dimerization equilibrium reaction of an inverted-topology, homodimeric fluoride channel Fluc in lipid bilayers. While the wild-type channel is a long-lived dimer, we leverage a known mutation, N43S, that weakens Na⁺ binding in a buried site at the interface, thereby unlocking the complex for reversible association in lipid bilayers. Single-channel recordings show that Na⁺ binding is required for fluoride conduction while single-molecule microscopy e

SUBMITTER: Ernst M 

PROVIDER: S-EPMC10666096 | biostudies-literature | 2023 Nov

REPOSITORIES: biostudies-literature