Early-stage dynamics of chloride ion-pumping rhodopsin revealed by a femtosecond X-ray laser.
basic_science · Level V
Where this comes from
- Record sourced from PubMed, PMID 33753488.
- Also identified by DOI 10.1073/pnas.2020486118 and PMC identifier 8020794.
- Licence recorded as CC BY.
- The licence permits redistribution, so the abstract is shown in full and the full text is available from the publisher.
Abstract
Chloride ion-pumping rhodopsin (ClR) in some marine bacteria utilizes light energy to actively transport Cl<sup>-</sup> into cells. How the ClR initiates the transport is elusive. Here, we show the dynamics of ion transport observed with time-resolved serial femtosecond (fs) crystallography using the Linac Coherent Light Source. X-ray pulses captured structural changes in ClR upon flash illumination with a 550 nm fs-pumping laser. High-resolution structures for five time points (dark to 100 ps after flashing) reveal complex and coordinated dynamics comprising retinal isomerization, water molecule rearrangement, and conformational changes of various residues. Combining data from time-resolved spectroscopy experiments and molecular dynamics simulations, this study reveals that the chloride ion close to the Schiff base undergoes a dissociation-diffusion process upon light-triggered retinal isomerization.
Medical subject headings
- Chloride Channels
- Chlorides
- Rhodopsins, Microbial