High-resolution Crystal Structures of Transient Intermediates in the Phytochrome Photocycle
Category
Published on
Type
posted-content
Author
Melissa Carrillo and Suraj Pandey and Juan Sanchez and Moraima Noda and Ishwor Poudyal and Luis Aldama and Tek Narsingh Malla and Elin Claesson and Weixiao Yuan Wahlgren and Denisse Feliz and Vukica Šrajer and Michal Maj and Leticia Castillon and So Iwata and Eriko Nango and Rie Tanaka and Tomoyuki Tanaka and Luo Fangjia and Kensuke Tono and Shigeki Owada and Sebastian Westenhoff and Emina A. Stojković and Marius Schmidt
Citation
Carrillo, M. et al., 2020. High-resolution Crystal Structures of Transient Intermediates in the Phytochrome Photocycle. Available at: http://dx.doi.org/10.1101/2020.09.16.298463.
Abstract
AbstractPhytochromes are red/far-red light photoreceptors in bacteria to plants, which elicit a variety of important physiological responses. They display a reversible photocycle between the resting (dark) Pr state and the light activated Pfr state, in which light signals are received and transduced as structural change through the entire protein to modulate the activity of the protein. It is unknown how the Pr-to-Pfr interconversion occurs as the structure of intermediates remain notoriously elusive. Here, we present short-lived crystal structures of the classical phytochrome from myxobacterium Stigmatella aurantiaca captured by an X-ray Free Electron Laser 5 ns and 33ms after light illumination of the Pr state. We observe large structural displacements of the covalently bound bilin chromophore, which trigger a bifurcated signaling pathway. The snapshots show with atomic precision how the signal progresses from the chromophore towards the output domains, explaining how plants, bacteria and fungi sense red light.
