Oxygen-evolving complex structure

Penner-Hahn JE (1998) Structural Characterization of the Mn Site in the Photosynthetic Oxygen-Evolving Complex. 90 1-36... 

Fig. 19. One of the structures included in an extensive evaluation study of magnetic and spectroscopic properties for models of the S2 state of the oxygen evolving complex.

Kulik LV, Epel B, Lubitz W, Messinger J. Electronic structure of the MnRJxCa cluster in the So and S2 states of the oxygen-evolving complex of photosystem II based on pulse 55Mn ENDOR and EPR spectroscopy. J Am Chem Soc. 2007 129(44) 13421-35. 

Ames W, Pantazis DA, Krewald V, et al. Theoretical evaluation of structural models of the S2 state in the oxygen evolving complex of photosystem II protonation states and magnetic interactions. J Am Chem Soc. 2011 133(49) 19743-57. 

Liang WC, Roelofs TA, Cinco RM, et al. Structural change of the Mn cluster during the S2 —> S3 state transition of the oxygen-evolving complex of photosystem II. Does it reflect the onset of water/substrate oxidation Determination by Mn X-ray absorption spectroscopy. J Am Chem Soc. 2000 122(14) 3 399 412. 

Glatzel P, Bergmann U, Yano J, et al. The electronic structure of Mn in oxides, coordination complexes, and the oxygen-evolving complex of photosystem II studied by resonant inelastic X-ray scattering. J Am Chem Soc. 2004 126(32) 9946-59. 

Pantazis DA, Ames W, Cox N, Lubitz W, Neese F. Two interconvertible structures that explain the spectroscopic properties of the oxygen evolving complex of photosystem II in the S2 state. Angew Chem Int Ed 2012 51(39) 9935-40. 

Quantum Mechanics/Molecular Mechanics Structural Models of the Oxygen-Evolving Complex of Photosystem II , Eduardo M. Sproviero, Jose A. Gasc6n, James P. McEvoy, Gary W. Brudvig and Victor S. Batista (2007) Curr. Opin. Struct. Biol. 17, 173-180. 

Figure 4 Structure of the oxygen-evolving complex of PS II as derived from single-crystal EXAFS (28) and X-ray scattering (3) data. The Mn, Ca, and O atoms of the OEC are shown in green, gray, and red, respectively, and have been determined by the best fit of a model consistent with the EXAFS data into the electron density map obtained by X-ray scattering experiments (28).

VK Yachandra, RD Guiles, AE McDermott, J Cole, RD Britt, SL Dexheimer, K Sauer and MP Klein (1987) Comparison ofthe structure ofthe manganese complex in the S, and S2 states of the photosynthetic oxygen-evolving complex An X-ray absorption spectroscopy study. Biochemistry 26 5974-5981... 

Other oxidases also derive function from bidirectional PCET pathways at the enzyme active site. The recent crystal structures of PSII [206, 207] support suggestions that as the oxygen evolving complex (OEC) steps through its various S-states [208, 209], substrate derived protons are shuttled to the lumen via a proton exit channel, the headwater of which appears to be the Dgi residue hydrogen-bonded to Mn-bound water [210]. The protons are liberated with the proton-coupled oxidation of the Mn-OH2 site. As shown by the structure reproduced in Fig. 17.23, Dgj is diametrically opposite to Y, which has long been known [148, 151, 152] to be the electron relay between the PS II reaction center and OEC. Notwithstanding,... 

Figure 17.23 The 3.4 A resolution structure of the oxygen evolving complex (OEC) and the immediate peptide environment. The directions of proposed PT and ET pathways are indicated with arrows. Figure adapted from Ref [206].

Renner-Hahn, J. 1998. Structural characterization of the Mn site in the photosynthetic oxygen-evolving complex. Struc. and Bonding 90 1-36. 

A (238). It is conjectured that a metal-metal bond may be present in the tris( j.-oxo) complex, but firm evidence is lacking. The 2.6-2.7 A Mn-Mn distance found for the bis( x-oxo) complexes make the Mnz02 unit the favored structural motif to account for the 1.1-K distance found for the oxygen evolving complex in Photosystem II (234). 

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