Closed and open structures of the eukaryotic magnesium channel Mrs2 reveal the auto-ligand-gating regulation mechanism.

ABSTRACT: The CorA/Mrs2 family of pentameric proteins are cardinal for the influx of Mg²⁺ across cellular membranes, importing the cation to mitochondria in eukaryotes. Yet, the conducting and regulation mechanisms of permeation remain elusive, particularly for the eukaryotic Mrs2 members. Here, we report closed and open Mrs2 cryo-electron microscopy structures, accompanied by functional characterization. Mg²⁺ flux is permitted by a narrow pore, gated by methionine and arginine residues in the closed state. Transition between the conformations is orchestrated by two pairs of conserved sensor-serving Mg²⁺-binding sites in the mitochondrial matrix lumen, located in between monomers. At lower levels of Mg²⁺, these ions are stripped, permitting an alternative,

SUBMITTER: Li P 

PROVIDER: S-EPMC11919701 | biostudies-literature | 2025 Mar

REPOSITORIES: biostudies-literature