Protein dynamics of a light-driven Na⁺ pump rhodopsin probed using a tryptophan residue near the retinal chromophore.

ABSTRACT: Direct observation of protein structural changes during ion transport in ion pumps provides valuable insights into the mechanism of ion transport. In this study, we examined structural changes in the light-driven sodium ion (Na⁺) pump rhodopsin KR2 on the sub-millisecond time scale, corresponding with the uptake and release of Na⁺. We compared the ion-pumping activities and transient absorption spectra of WT and the W215F mutant, in which the Trp215 residue located near the retinal chromophore on the cytoplasmic side was replaced with a Phe residue. Our findings indicated that atomic contacts between the bulky side chain of Trp215 and the C20 methyl group of the retinal chromophore promote relaxation of the retinal chromophore from the 13-cis to the all-tran

SUBMITTER: Otomo A 

PROVIDER: S-EPMC10865881 | biostudies-literature | 2023 Mar

REPOSITORIES: biostudies-literature