S3 State of the O2-Evolving Complex of Photosystem II: Insights from QM/MM, EXAFS, and Femtosecond X-ray Diffraction

Mikhail Askerka, Jimin Wang, David J. Vinyard, Gary W Brudvig, Victor S. Batista

Research output: Contribution to journalArticle

36 Citations (Scopus)


The oxygen-evolving complex (OEC) of photosystem II has been studied in the S3 state by electron paramagnetic resonance, extended X-ray absorption fine structure (EXAFS), and femtosecond X-ray diffraction (XRD). However, the actual structure of the OEC in the S3 state has yet to be established. Here, we apply hybrid quantum mechanics/molecular mechanics methods and propose a structural model that is consistent with EXAFS and XRD. The model supports binding of water ligands to the cluster in the S2 → S3 transition through a carousel rearrangement around Mn4, inspired by studies of ammonia binding.

Original languageEnglish
Pages (from-to)981-984
Number of pages4
Issue number7
Publication statusPublished - Mar 1 2016


ASJC Scopus subject areas

  • Biochemistry

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