Fig. 4: Structures and spectra of active states.
From: Structural insights into light-driven anion pumping in cyanobacteria
A Cryotrapping of the O state of the SyHR photocycle in crystals. Visible light absorption spectra of the red crystals of SyHR before (black line) and after (red line) illumination by the 532-nm laser for 2 seconds at 293 K. B Cryotrapping of the K state of the SyHR photocycle in crystals. Visible light absorption spectra of the red crystals of SyHR before (black line) and after (blue line) illumination by the 532-nm laser for 1 minute at 100 K. C Structure of the RSB region in the O state. (D) Structure of the retinal-binding pocket in the K state. Ground state positions of amino acids and retinal are shown as transparent. The cofactor retinal and K205 are colored cyan. (E) The scheme of the retinal isomerization from all-trans to 6-s-cis, 12-s-cis form. The fixed parts of the retinal are shown in the form of colored blocks.
