Abstract
We introduce a quantum mechanics/molecular mechanics model of the oxygen-evolving complex of photosystem II in the S 1 Mn 4(IV,III,IV,III) state, where Ca 2+ is bridged to manganese centers by the carboxylate moieties of D170 and A344 on the basis of the new X-ray diffraction (XRD) model recently reported at 1.9 Å resolution. The model is also consistent with high-resolution spectroscopic data, including polarized extended X-ray absorption fine structure data of oriented single crystals. Our results provide refined intermetallic distances within the Mn cluster and suggest that the XRD model most likely corresponds to a mixture of oxidation states, including species more reduced than those observed in the catalytic cycle of water splitting.
Original language | English |
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Pages (from-to) | 6308-6311 |
Number of pages | 4 |
Journal | Biochemistry |
Volume | 50 |
Issue number | 29 |
DOIs | |
Publication status | Published - Jul 26 2011 |
ASJC Scopus subject areas
- Biochemistry