title: Structure of the Mn4-Ca cluster as derived from X-ray diffraction.
abstract: The catalytic centre for light-induced water oxidation in photosystem II (PSII) is a multinuclear metal cluster containing four manganese and one calcium cations. Knowing the structure of this biological catalyst is of utmost importance for unravelling the mechanism of water oxidation in photosynthesis. In this review we describe the current state of the X-ray structure determination at 3.0 A resolution of the water oxidation complex (WOC) of PSII. The arrangement of metal cations in the cluster, their coordination and protein surroundings are discussed with regard to spectroscopic and mutagenesis studies. Limitations of the presently available structural data are pointed out and possible perspectives for the future are outlined, including the combination of X-ray diffraction and X-ray spectroscopy on single crystals.
authors.affiliation: Institut für Chemie, Max Volmer Laboratorium für Biophysikalische Chemie, Sekr. PC 14, Technische Universität Berlin, Strasse des 17. Juni 135, 10623 Berlin, Germany. kern@chem.tu-berlin.de
authors.forename: Jan
authors.initials: J
authors.lastname: Kern
authors.forename: Jacek
authors.initials: J
authors.lastname: Biesiadka
authors.forename: Bernhard
authors.initials: B
authors.lastname: Loll
authors.forename: Wolfram
authors.initials: W
authors.lastname: Saenger
authors.forename: Athina
authors.initials: A
authors.lastname: Zouni
mesh_terms: D002118:Calcium / Q000737:chemistry* / Q000378:metabolism; D008345:Manganese / Q000737:chemistry* / Q000378:metabolism; D010084:Oxidation-Reduction; D045332:Photosystem II Protein Complex / Q000737:chemistry* / Q000378:metabolism; D014867:Water / Q000378:metabolism; D014961:X-Ray Diffraction
chemical_list: D045332:Photosystem II Protein Complex; D014867:Water; D008345:Manganese; D002118:Calcium