Calcium induces binding and formation of a spin-coupled dimanganese(II,II) center in the apo-water oxidation complex of photosystem II as precursor to the functional tetra-Mn/Ca cluster.

@article{Ananyev1997CalciumIB,
  title={Calcium induces binding and formation of a spin-coupled dimanganese(II,II) center in the apo-water oxidation complex of photosystem II as precursor to the functional tetra-Mn/Ca cluster.},
  author={Gennady M. Ananyev and G Charles Dismukes},
  journal={Biochemistry},
  year={1997},
  volume={36 38},
  pages={11342-50}
}
Two new intermediates are described which form in the dark as precursors to the light-induced assembly of the photosynthetic water oxidation complex (WOC) from the inorganic components. Mn2+ binds to the apo-WOC-PSII protein in the absence of calcium at a high-affinity site. By using a hydrophobic chelator to remove Mn2+ and Ca2+ from the WOC and nonspecific Fe3+, a new EPR signal becomes visible upon binding of Mn2+ to this site, characterized by six-line 55Mn hyperfine structure (DeltaHpp… CONTINUE READING