Download MendeleyAn additional water is introduced into the manganese cluster during the formation of the S 3 state of photosystem II.
Bhowmick, A., Zhang, M., Simon, P.S., Makita, H., Nangca, I.I., Szilagyi, E., Kretzschmar, M., Doyle, M.D., Minnetian, N.M., Hussein, R., Hart, O., Chatterjee, K., Aydin, A.O., Shevela, D., Cheah, M.H., Croy, N., Chernev, P., Fransson, T., Tiwari, V., Sanchez, H., Schleissner, P., Lemons, R., Gate, G., Henstridge, M., Glownia, J.M., Poitevin, F., Rosenberg, D.J., Dehe, S., Gee, L.B., Tono, K., Owada, S., Oggenfuss, R., Ozerov, D., Sander, M., Mankowsky, R., Lemke, H.T., Young, I.D., Holton, J.M., Mittan-Moreau, D.W., Paley, D.W., Afonine, P.V., Moriarty, N.W., Adams, P.D., Mamedov, F., Dobbek, H., Zouni, A., Alonso-Mori, R., Bergmann, U., Brewster, A.S., Sauter, N.K., Messinger, J., Kern, J.F., Yachandra, V.K., Yano, J.(2026) Nat Commun 17
- PubMed: 42632826 Search on PubMedSearch on PubMed Central
- DOI: https://doi.org/10.1038/s41467-026-76805-9
- Primary Citation Related Structures:
9Z33, 9Z34, 9Z35, 9Z36, 9Z37, 9Z68, 9Z69, 9Z6A - PubMed Abstract:
During photosynthetic water oxidation, the Mn 4 Ca cluster in Photosystem II progresses through five intermediate S i (i = 0-4) states. X-ray crystallography studies have reported the insertion of one new O ligand during the formation of the S 3 state, but recent studies question the presence of this additional ligand based on cryo-EM and earlier room-temperature crystallography data. There is also controversy about whether the O-O bond interaction already occurs in the S 3 state or in the subsequent S 3 to S 0 transition. Here we report conventional high-resolution data for the S 1 , S 2 , and S 3 states to a resolution of ~1.9 Å, and anomalous diffraction data at two energies (9.5 keV and 7 keV), that was used to model the Mn positions, followed by determination of oxygen positions using the high-resolution maps. We show that the new oxygen atom, O X (or O6), in the S 3 state is observable as a distinct peak without any restraints, confirming its ligation to Mn1 and Ca. The O X -O5 distance is ~2.1 Å, supporting no strong interaction between them in the S 3 state, suggesting that if this is the O-O bond formation site, it is formed during the S 3 to S 0 transition initiated by the final oxidation of the cluster.
- Molecular Biophysics and Integrated Bioimaging Division, Lawrence Berkeley National Laboratory, Berkeley, CA, USA.
Organizational Affiliation:
