The water-oxidation complex in photosynthesis

Studies of the photosynthetic water-oxidation complex of photosystem II (PS II) using spectroscopic techniques have characterized not only important structural features, but also changes that occur in oxidation state of the Mitt cluster and in its internal organization during the accumulation of oxidizing equivalents leading to 02 formation. Combining this spectroscopic information with that from the recently published relatively low-resolution X-ray diffraction studies, we have succeeded in limiting the range of likely cluster arrangements. This evidence strongly supports several options proposed earlier by DeRose et al. [J. Am. Chem. Soc. 116 (1994) 5239] and these can be further narrowed using compatibility with electron paramagnetic resonance (EPR) data. (C) 2004 Elsevier B.V. All rights reserved.