title: Recent developments in biological water oxidation.
abstract: Rapid progress has been made in the last five years towards resolution of the structure of nature's water splitting catalyst - a Mn4O5Ca cofactor embedded in Photosystem II - especially in the field of X-ray crystallography. In addition, recent magnetic resonance data have allowed the structure of the cofactor to be accessed in its last metastable intermediate state, prior to O-O bond formation. This activated form of the catalyst is geometrically similar to that seen by X-ray crystallography, which represents the resting state of the cofactor, but requires the coordination of an additional water molecule to the cofactor, rendering all Mn ions six coordinate. Importantly, it locates two water derived, Mn bound oxygen ligands in close proximity. It is these two oxygen ligands that likely form the product O2 molecule, as proposed earlier by quantum chemical modeling. Current views on the molecular level events that facilitate catalyst activation, that is, catalyst/substrate deprotonation, Mn oxidation and water molecule insertion are briefly described.
authors.affiliation: Max Planck Institute for Chemical Energy Conversion, Stiftstr. 34-36, D-45470 Mülheim an der Ruhr, Germany.
authors.forename: Montserrat
authors.initials: M
authors.lastname: Pérez-Navarro
authors.affiliation: Max Planck Institute for Chemical Energy Conversion, Stiftstr. 34-36, D-45470 Mülheim an der Ruhr, Germany.
authors.forename: Frank
authors.initials: F
authors.lastname: Neese
authors.affiliation: Max Planck Institute for Chemical Energy Conversion, Stiftstr. 34-36, D-45470 Mülheim an der Ruhr, Germany.
authors.forename: Wolfgang
authors.initials: W
authors.lastname: Lubitz
authors.affiliation: Max Planck Institute for Chemical Energy Conversion, Stiftstr. 34-36, D-45470 Mülheim an der Ruhr, Germany.
authors.forename: Dimitrios A
authors.initials: DA
authors.lastname: Pantazis
authors.affiliation: Max Planck Institute for Chemical Energy Conversion, Stiftstr. 34-36, D-45470 Mülheim an der Ruhr, Germany; Research School of Chemistry, Australian National University, Canberra, ACT 2601, Australia. Electronic address: nicholas.cox@cec.mpg.de.
authors.forename: Nicholas
authors.initials: N
authors.lastname: Cox
mesh_terms: D003461:Crystallography; D010084:Oxidation-Reduction; D014867:Water / Q000737:chemistry*
chemical_list: D014867:Water