High-Resolution Mn EXAFS of the Oxygen-Evolving Complex inPhotosystem II: Structural Implications for the Mn4Ca Cluster

Journal Article · Tue Sep 06 04:00:00 EDT 2005 · Journal of the American Chemical Society

DOI:https://doi.org/10.1021/ja054873a· OSTI ID:877682

Yano, Junko; Pushkar, Yulia; Glatzel, Pieter; Lewis, Azul; Sauer, Kenneth; Messinger, Johannes; Bergmann, Uwe; Yachandra, Vittal

The biological generation of oxygen by the oxygen-evolving complex in photosystem II (PS II) is one of natures most important reactions. The recent X-ray crystal structures, while limited by resolutions of 3.2 to 3.5 A, have located the electron density associated with the Mn4Ca complex within the multi-protein PS II complex. Detailed structures critically depend on input from spectroscopic techniques such as EXAFS and EPR/ENDOR, as the XRD resolution does not allow for accurate determination of the position of Mn/Ca or the bridging and terminal ligand atoms. The number and distances of Mn-Mn/Ca/ligand interactions determined from EXAFS provide important constraints for the structure of the Mn cluster. Here we present data from a high-resolution EXAFS method using a novel multi-crystal monochromator that show three short Mn-Mn distances between 2.7 and 2.8 A and hence the presence of three di-mu-oxobridged units in the Mn4Ca cluster. This result imposes clear limitations on the proposed structures based on spectroscopic and diffraction data and provides input for refining such structures.

• Research Organization: Ernest Orlando Lawrence Berkeley NationalLaboratory, Berkeley, CA (US)
• Sponsoring Organization: USDOE Director. Office of Science. Office of Basic EnergySciences. Chemical Sciences Geosciences and Biosciences Division; National Institutes of Health RR-08630 and Grants GM-55302 and GM-65440,National Science Foundation Grant CHE-0213592
• DOE Contract Number: AC02-05CH11231
• OSTI ID: 877682
• Report Number(s): LBNL--58781; BnR: KC0304000
• Journal Information: Journal of the American Chemical Society, Journal Name: Journal of the American Chemical Society Journal Issue: 43 Vol. 127; ISSN JACSAT; ISSN 0002-7863
• Country of Publication: United States
• Language: English

Related Subjects

14 SOLAR ENERGY
36 MATERIALS SCIENCE
37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CHEMISTRY
59 BASIC BIOLOGICAL SCIENCES
ATOMS
CRYSTAL STRUCTURE
DIFFRACTION
ELECTRON DENSITY
MONOCHROMATORS
OXYGEN
REFINING
RESOLUTION
X-RAY DIFFRACTION