The Mn₄Ca photosynthetic water-oxidation catalyst studied by simultaneous X-ray spectroscopy and crystallography using an X-ray free-electron laser

Philos Trans R Soc Lond B Biol Sci. 2014 Jul 17;369(1647):20130324. doi: 10.1098/rstb.2013.0324.

Abstract

The structure of photosystem II and the catalytic intermediate states of the Mn₄CaO₅ cluster involved in water oxidation have been studied intensively over the past several years. An understanding of the sequential chemistry of light absorption and the mechanism of water oxidation, however, requires a new approach beyond the conventional steady-state crystallography and X-ray spectroscopy at cryogenic temperatures. In this report, we present the preliminary progress using an X-ray free-electron laser to determine simultaneously the light-induced protein dynamics via crystallography and the local chemistry that occurs at the catalytic centre using X-ray spectroscopy under functional conditions at room temperature.

Keywords: X-ray crystallography; X-ray emission spectroscopy; X-ray free-electron laser; manganese; oxygen-evolving complex; photosystem II.

Publication types

  • Research Support, N.I.H., Extramural
  • Research Support, Non-U.S. Gov't
  • Research Support, U.S. Gov't, Non-P.H.S.

MeSH terms

  • Calcium Compounds / chemistry*
  • Catalytic Domain
  • Crystallography, X-Ray / methods
  • Light*
  • Manganese Compounds / chemistry*
  • Models, Molecular*
  • Molecular Conformation
  • Photosystem II Protein Complex / chemistry*
  • Spectrometry, X-Ray Emission / methods*
  • Water / chemistry
  • X-Ray Diffraction / methods*

Substances

  • Calcium Compounds
  • Manganese Compounds
  • Photosystem II Protein Complex
  • Water