Room temperature femtosecond X-ray diffraction of photosystem II microcrystals

Jan Kern, Roberto Alonso-Mori, Julia Hellmich, Rosalie Tran, Johan Hattne, Hartawan Laksmono, Carina Glöckner, Nathaniel Echols, Raymond G. Sierra, Jonas Sellberg, Benedikt Lassalle-Kaiser, Richard J. Gildea, Pieter Glatzel, Ralf W. Grosse-Kunstleve, Matthew J. Latimer, Trevor A. McQueen, Dörte DiFiore, Alan R. Fry, Marc Messerschmidt, Alan MiahnahriDonald W. Schafer, M. Marvin Seibert, Dimosthenis Sokaras, Tsu Chien Weng, Petrus H. Zwart, William E. White, Paul D. Adams, Michael J. Bogan, Sébastien Boutet, Garth J. Williams, Johannes Messinger, Nicholas K. Sauter, Athina Zouni, Uwe Bergmann, Junko Yano, Vittal K. Yachandra

Research output: Contribution to journalArticlepeer-review

150 Scopus citations


Most of the dioxygen on earth is generated by the oxidation of water by photosystem II (PS II) using light from the sun. This light-driven, four-photon reaction is catalyzed by the Mn 4CaO 5 cluster located at the lumenal side of PS II. Various X-ray studies have been carried out at cryogenic temperatures to understand the intermediate steps involved in the water oxidation mechanism. However, the necessity for collecting data at room temperature, especially for studying the transient steps during the O-O bond formation, requires the development of new methodologies. In this paper we report room temperature X-ray diffraction data of PS II microcrystals obtained using ultrashort (<50 fs) 9 keV X-ray pulses from a hard X-ray free electron laser, namely the Linac Coherent Light Source. The results presented here demonstrate that the "probe before destroy" approach using an X-ray free electron laser works even for the highly-sensitive Mn 4CaO 5 cluster in PS II at room temperature. We show that these data are comparable to those obtained in synchrotron radiation studies as seen by the similarities in the overall structure of the helices, the protein subunits and the location of the various cofactors. This work is, therefore, an important step toward future studies for resolving the structure of the Mn 4CaO 5 cluster without any damage at room temperature, and of the reaction intermediates of PS II during O-O bond formation.

Original languageEnglish (US)
Pages (from-to)9721-9726
Number of pages6
JournalProceedings of the National Academy of Sciences of the United States of America
Issue number25
StatePublished - Jun 19 2012
Externally publishedYes


  • Manganese
  • Oxygen-evolving complex

ASJC Scopus subject areas

  • General


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