@article{9b1ab8c692624fa0a1612b36b31f2ae9,
title = "Taking snapshots of photosynthetic water oxidation using femtosecond X-ray diffraction and spectroscopy",
abstract = "The dioxygen we breathe is formed by light-induced oxidation of water in photosystem II. O2 formation takes place at a catalytic manganese cluster within milliseconds after the photosystem II reaction centre is excited by three single-turnover flashes. Here we present combined X-ray emission spectra and diffraction data of 2-flash (2F) and 3-flash (3F) photosystem II samples, and of a transient 3F′ state (250μs after the third flash), collected under functional conditions using an X-ray free electron laser. The spectra show that the initial O-O bond formation, coupled to Mn reduction, does not yet occur within 250μs after the third flash. Diffraction data of all states studied exhibit an anomalous scattering signal from Mn but show no significant structural changes at the present resolution of 4.5{\AA}. This study represents the initial frames in a molecular movie of the structural changes during the catalytic reaction in photosystem II.",
author = "Jan Kern and Rosalie Tran and Roberto Alonso-Mori and Sergey Koroidov and Nathaniel Echols and Johan Hattne and Mohamed Ibrahim and Sheraz Gul and Hartawan Laksmono and Sierra, {Raymond G.} and Gildea, {Richard J.} and Guangye Han and Julia Hellmich and Benedikt Lassalle-Kaiser and Ruchira Chatterjee and Brewster, {Aaron S.} and Stan, {Claudiu A.} and Carina Gl{\"o}ckner and Alyssa Lampe and D{\"o}rte Difiore and Despina Milathianaki and Fry, {Alan R.} and Seibert, {M. Marvin} and Koglin, {Jason E.} and Erik Gallo and Jens Uhlig and Dimosthenis Sokaras and Weng, {Tsu Chien} and Zwart, {Petrus H.} and Skinner, {David E.} and Bogan, {Michael J.} and Marc Messerschmidt and Pieter Glatzel and Williams, {Garth J.} and S{\'e}bastien Boutet and Adams, {Paul D.} and Athina Zouni and Johannes Messinger and Sauter, {Nicholas K.} and Uwe Bergmann and Junko Yano and Yachandra, {Vittal K.}",
note = "Funding Information: This work was supported by NIH Grant GM055302 (V.K.Y) for PS II biochemistry, structure and mechanism; the Director, Office of Science, Office of Basic Energy Sciences (OBES), Division of Chemical Sciences, Geosciences and Biosciences (CSGB) of the Department of Energy (DOE) under Contract DE-AC02-05CH11231 (J.Y. and V.K.Y.) for X-ray methodology and instrumentation; by NIH grant P41GM103393 for part of the XES instrumentation and support of U.B.; an LBNL Laboratory Directed Research and Development award to N.K.S; and NIH grants GM095887 and GM102520 (N.K.S.) for data processing methods. The DFG-Cluster of Excellence {\textquoteleft}UniCat{\textquoteleft} coordinated by the Technische Universit{\"a}t Berlin and Sfb1078, TP A5 (A.Z.); the Alexander von Humboldt Foundation (J.K.); the European Union Seventh Framework Programme (FP7/2007-2013) under grant agreement no 283745 (CRISP) (P.G.); the Solar Fuels Strong Research Environment (Ume{\aa} University), the Artificial Leaf Project (K&A Wallenberg Foundation), Energimyndigheten (J.M.) and VR (M.M.S., J.M.), and the Human Frontiers Science Project (J.Y., U.B. and A.Z.) are acknowledged for supporting this project. The injector work was supported by DOE Office of Basic Energy Sciences, Chemical Sciences Division, under Contract DE-AC02-76SF00515 (H.L., C.A.S. and M.J.B.), LCLS (R.G.S.), the Human Frontiers Science Project Award RPG005/2011 (H.L.) and the SLAC Laboratory Directed Research and Development Program (C.A.S. and M.J.B.). We thank Professor Ken Sauer for continuing scientific discussions. We thank Tom Terwilliger, Randy Read, Nigel Moriarty, Ralf Grosse-Kunstleve, Pavel Afonine and Jeffrey Headd for helpful discussions and technical assistance regarding XRD data processing; Matthew Latimer for support with the XES set-up; Don Schaefer, Alan Miahnahri and William White for support with development of the laser illumination and injector set-up; Christopher Kenney, Ryan Herbst, Jack Pines, Philip Hart, John Morse, Gunther Haller and Sven Herrmann for support with the CSPAD detectors; Amedeo Perazzo and Igor Gaponenko (SLAC) for computing support; Gregory Bell (Energy Sciences Network (ESnet)) for arranging network access for data transfer; and Shane Canon (NERSC) for arranging computing access. We thank the staff at LCLS/SLAC and the staff at SSRL, ALS, APS and ESRF for support of synchrotron experiments. Portions of this research were carried out at the Linac Coherent Light Source (LCLS) at the SLAC National Accelerator Laboratory. LCLS is an Office of Science User Facility operated for the U.S. Department of Energy Office of Science by Stanford University. Data processing was performed in part at the National Energy Research Scientific Computing Center, supported by the DOE Office of Science, contract number DE-AC02-05CH11231. Testing of crystals and various parts of the set-up were carried out at synchrotron facilities that were provided by the Advanced Light Source (ALS), BL 5.0.2, in Berkeley, and Stanford Synchrotron Radiation Lightsource (SSRL), BL 6-2, in Stanford, funded by DOE OBES. The SSRL Biomedical Technology programme is supported by NIH, the National Center for Research Resources and the DOE Office of Biological and Environmental Research. SR PS II XES data were recorded at the European Synchrotron Radiation Facility (ESRF), Grenoble, France.",
year = "2014",
month = jul,
day = "9",
doi = "10.1038/ncomms5371",
language = "English (US)",
volume = "5",
journal = "Nature communications",
issn = "2041-1723",
publisher = "Nature Publishing Group",
}