Vision begins with the photoisomerization of the chromophore 11-cis-retinal (11cR) to its all-trans form in visual rhodopsins. To regenerate visual rh…

Two phylogenetically distinct groups of microbial rhodopsins show light-induced inward proton transport activity, xenorhodopsins (XeRs) and schizorhodopsins (SzRs). However, structural insights into i...

Microbial rhodopsins are key light-harvesting proteins for energy conversion in aquatic environments. While typically reliant on retinal, xanthorhodopsins (XRs) also employ carotenoids as antenna pigm...

Understanding the photodynamics of rhodopsin is crucial for elucidating light-induced biological processes. This study investigates the excited-state properties and isomerization dynamics of the microbial rhodopsin mimic protein, focusing on its all-trans (AT) and 13-cis (13C) conformations. By scanning the C13═C14 dihedral angle, we revealed distinct isomerization pathways for the two conformations. In the all-trans conformation, the crossing of S1 and S2 energy levels results in significant electronic state mixing, slowing the isomerization rate and extending the excited-state lifetime. Furthermore, the interaction between the chromophore and the protein varies markedly between the conformations, it is attractive in the 13-cis conformations, but repulsive near the mutation site in the all-trans conformations. These findings suggest that the repulsive force in the all-trans conformations may influence ground-state stability, indirectly affecting the excited-state isomerization process.

Apusomonads are sediment-dwelling bacterivorous protists that are sister to all Opisthokonta. They have been found to show a negative phototactic r...

Yasuhisa Mizutani marvels at how effectively nature utilizes the π-conjugated system of retinal in proteins.