Analysis of the Radiation-Damage-Free X-ray Structure of Photosystem II in Light of EXAFS and QM/MM Data

作者：Askerka Mikhail; Vinyard David J; Wang Jimin; Brudvig Gary W; Batista Victor S^*

来源：Biochemistry, 2015, 54(9): 1713-1716.

DOI：10.1021/acs.biochem.5b00089

A recent femtosecond X-ray diffraction study produced the first high-resolution structural model of the oxygen-evolving complex of photosystem II that is free of radiation-induced manganese reduction (Protein Data Bank entries 4UB6 and 4UB8). We find, however, that the model does not match extended X-ray absorption fine structure and QM/MM data for the S-1 state. This is attributed to uncertainty about the positions of oxygen atoms that remain partially unresolved, even at 1.95 angstrom resolution, next to the heavy manganese centers. In addition, the photosystem II crystals may contain significant amounts of the S-0 state, because of extensive dark adaptation prior to data collection.

• 出版日期2015-3-10