title: The extrinsic PsbO protein modulates the oxidation/reduction rate of the exogenous Mn cation at the high-affinity Mn-binding site of Mn-depleted PSII membranes.
abstract: The oxidation of exogenous Mn(II) cations at the high-affinity (HA) Mn-binding site in Mn-depleted photosystem II (PSII) membranes with or without the presence of the extrinsic PsbO polypeptide was studied by EPR. The six-lines EPR spectrum of Mn(II) cation disappears in the absence of the PsbO protein in membranes under illumination, but there was no effect when PSII preparations bound the PsbO protein. Our study demonstrates that such effect is determined by significant influence of the PsbO protein on the ratio between the rates of Mn oxidation and reduction at the HA site when the membranes are illuminated.
authors.affiliation: Department of Biophysics, Faculty of Biology, Lomonosov Moscow State University, 119234, Moscow, Russia, semin@biophys.msu.ru.
authors.forename: Boris K
authors.initials: BK
authors.lastname: Semin
authors.forename: Tatiana E
authors.initials: TE
authors.lastname: Podkovirina
authors.forename: Lira N
authors.initials: LN
authors.lastname: Davletshina
authors.forename: Kirill N
authors.initials: KN
authors.lastname: Timofeev
authors.forename: Il'ya I
authors.initials: II
authors.lastname: Ivanov
authors.forename: Andrei B
authors.initials: AB
authors.lastname: Rubin
mesh_terms: D004578:Electron Spin Resonance Spectroscopy; D008345:Manganese / Q000737:chemistry*; D010084:Oxidation-Reduction; D045332:Photosystem II Protein Complex / Q000737:chemistry*; D018515:Plant Leaves / Q000737:chemistry*; D010940:Plant Proteins / Q000737:chemistry*; D018724:Spinacia oleracea / Q000737:chemistry*
chemical_list: D045332:Photosystem II Protein Complex; D010940:Plant Proteins; C052389:oxygen-evolving enhancer protein 1, plant; D008345:Manganese