Proteins of Oxygen Evolving Complexes of Photosystem II Studied by Means of Molecular Modeling and Vibrational Spectroscopy

R. Ettrich¹ and Z. Sovova¹

¹ Laboratory of High Performance Computing, Institute of Physical Biology of USB and Institute of Landscape Ecology of AS CR, Zámek 136, Nové Hrady, CZ-37333, Czech Republic

Homology and energetic modeling is used for the determination of the structure of several proteins of the oxygen evolving complex (PsbQ, PsbP and PsbO) bound to photosystem II of higher plants, spinach and pea. Structural and sequence alignment of the individual proteins of the oxygen evolving complex was performed to get a basis for homology modeling. Three-dimensional models of oxygen evolving complex proteins are suggested. These models will serve in future to get detailed information about the secondary structure content, the spatial arrangement and interactions of individual aromatic residues that can be confronted with results from vibrational spectroscopy. Spectroscopic data will serve as a feedback for the generation of three-dimensional models. Thus gained models will be used for the detection of interaction sites not only by Raman and FTIR, but will also be used for fitting into images of the whole complex of photosystem II taken by electron microscopy. The work presented here is the first step to determine the spatial arrangement of individual proteins in the oxygen evolving complex.

Supports from the Institutional Research Concept of the Academy of Science of the Czech Republic (No. AVOZ60870520) and from the Ministry of Education of the Czech Republic (No. MSM6007665808) and the Grant Agency of the Czech Republic (grant No. 206/03/D082) are gratefully acknowledged.