Multistep conformational changes leading to the gate opening of light-driven sodium pump rhodopsin.

ABSTRACT: Membrane transport proteins require a gating mechanism that opens and closes the substrate transport pathway to carry out unidirectional transport. The "gating" involves large conformational changes and is achieved via multistep reactions. However, these elementary steps have not been clarified for most transporters due to the difficulty of detecting the individual steps. Here, we propose these steps for the gate opening of the bacterial Na⁺ pump rhodopsin, which outwardly pumps Na⁺ upon illumination. We herein solved an asymmetric dimer structure of Na⁺ pump rhodopsin from the bacterium Indibacter alkaliphilus. In one protomer, the Arg108 sidechain is oriented toward the protein center and appears to block a Na⁺ release pathway to the extracellu

SUBMITTER: Sato Y 

PROVIDER: S-EPMC10679507 | biostudies-literature | 2023 Dec

REPOSITORIES: biostudies-literature