Calcium in the oxygen-evolving complex: structural and mechanistic role determined by X-ray spectroscopy

J Photochem Photobiol B. 2011 Jul-Aug;104(1-2):51-9. doi: 10.1016/j.jphotobiol.2011.02.019. Epub 2011 Mar 3.

Abstract

This review describes the results from X-ray Absorption Spectroscopy studies that have contributed to an understanding of the role of Ca in the photosynthetic water-oxidation reaction. The results include the first Mn, Ca and Sr X-ray spectroscopy studies using Ca or Sr-substituted PS II samples that established the presence of a MnCa heteronuclear structure and its orientation, and the most recent Sr X-ray spectroscopy study using biosynthetically prepared Sr-containing PS II in the various S-states that provide important insights into the requirement for Ca in the mechanism of the Mn(4)Ca catalytic center.

Publication types

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

MeSH terms

  • Calcium / chemistry
  • Calcium / physiology*
  • Catalytic Domain
  • Oxygen / chemistry*
  • Photosystem II Protein Complex / chemistry*
  • Photosystem II Protein Complex / metabolism
  • X-Ray Absorption Spectroscopy

Substances

  • Photosystem II Protein Complex
  • Oxygen
  • Calcium