Early-stage dynamics of chloride ion–pumping rhodopsin revealed by a femtosecond X-ray laser
Category
Published on
Type
journal-article
Author
Ji-Hye Yun and Xuanxuan Li and Jianing Yue and Jae-Hyun Park and Zeyu Jin and Chufeng Li and Hao Hu and Yingchen Shi and Suraj Pandey and Sergio Carbajo and Sébastien Boutet and Mark S. Hunter and Mengning Liang and Raymond G. Sierra and Thomas J. Lane and Liang Zhou and Uwe Weierstall and Nadia A. Zatsepin and Mio Ohki and Jeremy R. H. Tame and Sam-Yong Park and John C. H. Spence and Wenkai Zhang and Marius Schmidt and Weontae Lee and Haiguang Liu
Citation
Yun, J.-H. et al., 2021. Early-stage dynamics of chloride ion–pumping rhodopsin revealed by a femtosecond X-ray laser. Proceedings of the National Academy of Sciences, 118(13), p.e2020486118. Available at: http://dx.doi.org/10.1073/pnas.2020486118.
Abstract
Chloride ion–pumping rhodopsin (ClR) in some marine bacteria utilizes light energy to actively transport Cl− 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.
DOI
Funding
NSF-STC Biology with X-ray Lasers (NSF-1231306)