An additional water is introduced into the manganese cluster during the formation of the S3 state of photosystem II

An additional water is introduced into the manganese cluster during the formation of the S3 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. Nature Communications, 17(1):8818, Nature Publishing Group, August, 2026.

Paper doi abstract bibtex

During photosynthetic water oxidation, the Mn4Ca cluster in Photosystem II progresses through five intermediate Si (i = 0–4) states. X-ray crystallography studies have reported the insertion of one new O ligand during the formation of the S3 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 S3 state or in the subsequent S3 to S0 transition. Here we report conventional high-resolution data for the S1, S2, and S3 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, OX (or O6), in the S3 state is observable as a distinct peak without any restraints, confirming its ligation to Mn1 and Ca. The OX-O5 distance is ~2.1 Å, supporting no strong interaction between them in the S3 state, suggesting that if this is the O-O bond formation site, it is formed during the S3 to S0 transition initiated by the final oxidation of the cluster.

@article{bhowmick_additional_2026,
	title = {An additional water is introduced into the manganese cluster during the formation of the {S3} state of photosystem {II}},
	volume = {17},
	copyright = {2026 The Author(s)},
	issn = {2041-1723},
	url = {https://www.nature.com/articles/s41467-026-76805-9},
	doi = {10.1038/s41467-026-76805-9},
	abstract = {During photosynthetic water oxidation, the Mn4Ca cluster in Photosystem II progresses through five intermediate Si (i = 0–4) states. X-ray crystallography studies have reported the insertion of one new O ligand during the formation of the S3 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 S3 state or in the subsequent S3 to S0 transition. Here we report conventional high-resolution data for the S1, S2, and S3 states to a resolution of {\textasciitilde}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, OX (or O6), in the S3 state is observable as a distinct peak without any restraints, confirming its ligation to Mn1 and Ca. The OX-O5 distance is {\textasciitilde}2.1 Å, supporting no strong interaction between them in the S3 state, suggesting that if this is the O-O bond formation site, it is formed during the S3 to S0 transition initiated by the final oxidation of the cluster.},
	language = {en},
	number = {1},
	urldate = {2026-09-02},
	journal = {Nature Communications},
	publisher = {Nature Publishing Group},
	author = {Bhowmick, Asmit and Zhang, Miao and Simon, Philipp S. and Makita, Hiroki and Nangca, Isabela I. and Szilagyi, Erzsi and Kretzschmar, Moritz and Doyle, Margaret D. and Minnetian, Natalie M. and Hussein, Rana and Hart, Olli and Chatterjee, Kuntal and Aydin, A. Orkun and Shevela, Dmitry and Cheah, Mun Hon and Croy, Nicholas and Chernev, Petko and Fransson, Thomas and Tiwari, Vandana and Sanchez, Humberto and Schleissner, Pamela and Lemons, Randy and Gate, Greg and Henstridge, Meredith and Glownia, James M. and Poitevin, Frédéric and Rosenberg, Daniel J. and Dehe, Sebastian and Gee, Leland B. and Tono, Kensuke and Owada, Shigeki and Oggenfuss, Roland and Ozerov, Dmitry and Sander, Mathias and Mankowsky, Roman and Lemke, Henrik T. and Young, Iris D. and Holton, James M. and Mittan-Moreau, David W. and Paley, Daniel W. and Afonine, Pavel V. and Moriarty, Nigel W. and Adams, Paul D. and Mamedov, Fikret and Dobbek, Holger and Zouni, Athina and Alonso-Mori, Roberto and Bergmann, Uwe and Brewster, Aaron S. and Sauter, Nicholas K. and Messinger, Johannes and Kern, Jan F. and Yachandra, Vittal K. and Yano, Junko},
	month = aug,
	year = {2026},
	keywords = {Bioenergetics, Physical chemistry, Structural biology},
	pages = {8818},
}

Downloads: 0