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Peloquin JM, Campbell KA, Randall DW, Evanchik MA, Pecoraro VL, Armstrong WH, Britt RD. 55Mn ENDOR of the S2-State Multiline EPR Signal of Photosystem II: Implications on the Structure of the Tetranuclear Mn Cluster. J Am Chem Soc 2000. [DOI: 10.1021/ja002104f] [Citation(s) in RCA: 324] [Impact Index Per Article: 13.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Jeffrey M. Peloquin
- Contribution from the Department of Chemistry, University of California, Davis, California 95616, Department of Chemistry, Stanford University, Stanford, California 94305, Department of Chemistry, University of Michigan, Ann Arbor, Michigan 48103-1055, and Department of Chemistry, Boston College, Chestnut Hill, Massachussetts 02167
| | - Kristy A. Campbell
- Contribution from the Department of Chemistry, University of California, Davis, California 95616, Department of Chemistry, Stanford University, Stanford, California 94305, Department of Chemistry, University of Michigan, Ann Arbor, Michigan 48103-1055, and Department of Chemistry, Boston College, Chestnut Hill, Massachussetts 02167
| | - David W. Randall
- Contribution from the Department of Chemistry, University of California, Davis, California 95616, Department of Chemistry, Stanford University, Stanford, California 94305, Department of Chemistry, University of Michigan, Ann Arbor, Michigan 48103-1055, and Department of Chemistry, Boston College, Chestnut Hill, Massachussetts 02167
| | - Marc A. Evanchik
- Contribution from the Department of Chemistry, University of California, Davis, California 95616, Department of Chemistry, Stanford University, Stanford, California 94305, Department of Chemistry, University of Michigan, Ann Arbor, Michigan 48103-1055, and Department of Chemistry, Boston College, Chestnut Hill, Massachussetts 02167
| | - Vincent L. Pecoraro
- Contribution from the Department of Chemistry, University of California, Davis, California 95616, Department of Chemistry, Stanford University, Stanford, California 94305, Department of Chemistry, University of Michigan, Ann Arbor, Michigan 48103-1055, and Department of Chemistry, Boston College, Chestnut Hill, Massachussetts 02167
| | - William H. Armstrong
- Contribution from the Department of Chemistry, University of California, Davis, California 95616, Department of Chemistry, Stanford University, Stanford, California 94305, Department of Chemistry, University of Michigan, Ann Arbor, Michigan 48103-1055, and Department of Chemistry, Boston College, Chestnut Hill, Massachussetts 02167
| | - R. David Britt
- Contribution from the Department of Chemistry, University of California, Davis, California 95616, Department of Chemistry, Stanford University, Stanford, California 94305, Department of Chemistry, University of Michigan, Ann Arbor, Michigan 48103-1055, and Department of Chemistry, Boston College, Chestnut Hill, Massachussetts 02167
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Meinke C, Solé VA, Pospisil P, Dau H. Does the structure of the water-oxidizing photosystem II-manganese complex at room temperature differ from its low-temperature structure? A comparative X-ray absorption study. Biochemistry 2000; 39:7033-40. [PMID: 10852700 DOI: 10.1021/bi9924258] [Citation(s) in RCA: 30] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Detailed information on room-temperature structure and oxidation state of the Photosystem II (PS II) manganese complex is needed to put mechanistic considerations on solid grounds. Because previously this information had not been available, the tetranuclear manganese complex was investigated by X-ray absorption spectroscopy (XAS) on PS II membrane particles at 290 K. Due to methodical progress (collection of XAS spectra within 10 s or less), significant X-ray radiation damage can be avoided; room-temperature XAS investigations on the PS II in its native membrane environment become feasible. Thus, the ambiguity with respect to the mechanistic relevance of low-temperature XAS results is avoidable. At 290 K as well as at 18 K, the manganese complex in its dark-stable state (S(1)-state) seemingly is a Mn(III)(2)Mn(IV)(2) complex comprising two di-mu(2)-oxo bridged binuclear manganese units characterized by the same Mn-Mn distance of 2.71-2.72 A at both temperatures. Most likely, manganese oxidation states and the protonation state of the bridging oxides are fully temperature independent. Remarkably, at room-temperature manganese-ligand distances of 3.10 and 3.65 A are clearly discernible in the EXAFS spectra. The type of bridging assumed to result in Mn-Mn or Mn-Ca distances around 3.1 A is, possibly, temperature-dependent as suggested by distance lengthening upon cooling by 0.13 A. However, mechanistic proposals on photosynthetic water oxidation, which involve the dimer-of-dimers model [Yachandra, V. K., et al. (1993) Science 260, 675-679] are not invalidated by the presented results.
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Affiliation(s)
- C Meinke
- FB Biologie, Philipps-Universität Marburg, Lahnberge, Germany
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