Lawrence Berkeley National Laboratory (LBNL), Berkeley, CA (United States)
Hebrew Univ. of Jerusalem (Israel)
Lawrence Berkeley National Laboratory (LBNL), Berkeley, CA (United States); SLAC National Accelerator Laboratory (SLAC), Menlo Park, CA (United States). Linac Coherent Light Source (LCLS)
Lawrence Berkeley National Laboratory (LBNL), Berkeley, CA (United States); Univ. of Hamburg (Germany)
Technische Univ. Berlin (Germany)
Charité–Universitätsmedizin Berlin (Germany); Novo Nordisk (Denmark)
Charité–Universitätsmedizin Berlin (Germany); Francis Crick Institute, London (United Kingdom)
Science and Technology Facilities Council (STFC), Oxford (United Kingdom). Diamond Light Source, Ltd.
Imperial College, London (United Kingdom); Vrije Univ., Amsterdam (Netherlands)
Imperial College, London (United Kingdom); SLAC National Accelerator Laboratory (SLAC), Menlo Park, CA (United States). Linac Coherent Light Source (LCLS)
Imperial College, London (United Kingdom)
Rice Univ., Houston, TX (United States)
SLAC National Accelerator Laboratory (SLAC), Menlo Park, CA (United States). Linac Coherent Light Source (LCLS)
Japan Synchrotron Radiation Research Institute, Sayo, Hyogo (Japan); RIKEN SPring-8 Center, Sayo (Japan)
RIKEN SPring-8 Center, Sayo (Japan); Kyoto Univ. (Japan)
Karlsruhe Inst. of Technology (KIT) (Germany)
Hebrew Univ. of Jerusalem (Israel); Technical University Dortmund (Germany); University Alliance Ruhr, Bochum (Germany)
The photoreaction and commensurate structural changes of a chromophore within biological photoreceptors elicit conformational transitions of the protein promoting the switch between deactivated and activated states. We investigated how this coupling is achieved in a bacterial phytochrome variant, Agp2-PAiRFP2. Contrary to classical protein crystallography, which only allows probing (cryo-trapped) stable states, we have used time-resolved serial femtosecond x-ray crystallography (tr-SFX) and pump-probe techniques with various illumination and delay times with respect to photoexcitation of the parent Pfr state. Thus, structural data for seven time frames were sorted into groups of molecular events along the reaction coordinate. They range from chromophore isomerization to the formation of Meta-F, the intermediate that precedes the functional relevant secondary structure transition of the tongue. Structural data for the early events were used to calculate the photoisomerization pathway to complement the experimental data. Late events allow identifying the molecular switch that is linked to the intramolecular proton transfer as a prerequisite for the following structural transitions.
@article{osti_2572077,
author = {Sauthof, Luisa and Szczepek, Michal and Schmidt, Andrea and Bhowmick, Asmit and Dasgupta, Medhanjali and Mackintosh, Megan J. and Gul, Sheraz and Fuller, Franklin D. and Chatterjee, Ruchira and Young, Iris D. and others},
title = {Serial-femtosecond crystallography reveals how a phytochrome variant couples chromophore and protein structural changes},
annote = {The photoreaction and commensurate structural changes of a chromophore within biological photoreceptors elicit conformational transitions of the protein promoting the switch between deactivated and activated states. We investigated how this coupling is achieved in a bacterial phytochrome variant, Agp2-PAiRFP2. Contrary to classical protein crystallography, which only allows probing (cryo-trapped) stable states, we have used time-resolved serial femtosecond x-ray crystallography (tr-SFX) and pump-probe techniques with various illumination and delay times with respect to photoexcitation of the parent Pfr state. Thus, structural data for seven time frames were sorted into groups of molecular events along the reaction coordinate. They range from chromophore isomerization to the formation of Meta-F, the intermediate that precedes the functional relevant secondary structure transition of the tongue. Structural data for the early events were used to calculate the photoisomerization pathway to complement the experimental data. Late events allow identifying the molecular switch that is linked to the intramolecular proton transfer as a prerequisite for the following structural transitions.},
doi = {10.1126/sciadv.adp2665},
url = {https://www.osti.gov/biblio/2572077},
journal = {Science Advances},
issn = {ISSN 2375-2548},
number = {22},
volume = {11},
place = {United States},
publisher = {AAAS},
year = {2025},
month = {05}}
SLAC National Accelerator Laboratory (SLAC), Menlo Park, CA (United States)
Sponsoring Organization:
USDOE Office of Science (SC), Basic Energy Sciences (BES). Chemical Sciences, Geosciences & Biosciences Division (CSGB); National Institutes of Health (NIH); National Science Foundation (NSF)