Photoassembly of the water-oxidizing complex in photosystem II

Jyotishman Dasgupta, Gennady M. Ananyev, G. Charles Dismukes

Research output: Contribution to journalReview articlepeer-review

125 Citations (Scopus)


The light-driven steps in the biogenesis and repair of the inorganic core comprising the O2-evolving center of oxygenic photosynthesis (photosystem II water-oxidation complex, PSII-WOC) are reviewed. These steps, known collectively as photoactivation, involve the photoassembly of the free inorganic cofactors to the cofactor-depleted PSII-(apo-WOC) driven by light and produce the active O2-evolving core comprised of Mn4CaOxCly. We focus on the functional role of the inorganic components as seen through the competition with non-native cofactors ("inorganic mutants") on water oxidation activity, the rate of the photoassembly reaction, and on structural insights gained from EPR spectroscopy of trapped intermediates formed in the initial steps of the assembly reaction. A chemical mechanism for the initial steps in photoactivation is given that is based on these data. Photoactivation experiments offer the powerful insights gained from replacement of the native cofactors, which together with the recent X-ray structural data for the resting holoenzyme provide a deeper understanding of the chemistry of water oxidation. We also review some new directions in research that photoactivation studies have inspired that look at the evolutionary history of this remarkable catalyst.

Original languageEnglish
Pages (from-to)347-360
Number of pages14
JournalCoordination Chemistry Reviews
Issue number3-4
Publication statusPublished - Feb 2008


  • Bicarbonate
  • Calcium
  • Manganese
  • Oxygen-evolution
  • Photosynthesis
  • Photosystem II
  • Water oxidation

ASJC Scopus subject areas

  • Physical and Theoretical Chemistry
  • Inorganic Chemistry
  • Materials Chemistry

Fingerprint Dive into the research topics of 'Photoassembly of the water-oxidizing complex in photosystem II'. Together they form a unique fingerprint.

Cite this