Athina Zouni

TL;DR: The X-ray structure of photosystem II is described on the basis of crystals fully active in water oxidation, shows how protein subunits and cofactors are spatially organized and the larger subunits are assigned and the locations and orientations of the cofacters are defined.

TL;DR: The most complete cyanobacterial photosystem II structure obtained so far is described, showing locations of and interactions between 20 protein subunits and 77 cofactors per monomer, and provides information about the Mn4Ca cluster, where oxidation of water takes place.

TL;DR: Putative oxygen positions obtained from a Xenon derivative indicate a role for lipids in oxygen diffusion to the cytoplasmic side of PSII, and the chloride position suggests a role in proton-transfer reactions.

TL;DR: Polarized extended x-ray absorption fine structure measurements on PSII single crystals constrain the Mn4Ca cluster geometry to a set of three similar high-resolution structures, unlike either the 3.0 or 3.5 angstrom–resolution x-rays or other previously proposed models.

TL;DR: This case study shows that a careful evaluation of the structural intactness of the active site(s) by spectroscopic techniques can validate structures derived from crystallography and that it can be a valuable complementary method before structure-function correlations of metalloproteins can be made on the basis of high-resolution x-ray crystal structures.