Closing Kok’s cycle of nature’s water oxidation catalysis

Pantazis, D. A. Missing pieces in the puzzle of biological water oxidation. ACS Catal. 8, 9477–9507 (2018).Article 
CAS 

Google Scholar 
Shevela, D., Kern, J. F., Govindjee, G. & Messinger, J. Solar energy conversion by photosystem II: principles and structures. Photosynth. Res. 156, 279–307 (2023).Article 
CAS 
PubMed 
PubMed Central 

Google Scholar 
Suga, M. et al. Light-induced structural changes and the site of O=O bond formation in PSII caught by XFEL. Nature 543, 131–135 (2017).Article 
ADS 
CAS 
PubMed 

Google Scholar 
Kern, J. et al. Structures of the intermediates of Kok’s photosynthetic water oxidation clock. Nature 563, 421–425 (2018).Article 
ADS 
CAS 
PubMed 
PubMed Central 

Google Scholar 
Suga, M. et al. An oxyl/oxo mechanism for oxygen-oxygen coupling in PSII revealed by an x-ray free-electron laser. Science 366, 334–338 (2019).Article 
ADS 
CAS 
PubMed 

Google Scholar 
Ibrahim, M. et al. Untangling the sequence of events during the S2 → S3 transition in photosystem II and implications for the water oxidation mechanism. Proc. Natl Acad. Sci. USA 117, 12624–12635 (2020).Article 
ADS 
CAS 
PubMed 
PubMed Central 

Google Scholar 
Hussein, R. et al. Structural dynamics in the water and proton channels of photosystem II during the S2 to S3 transition. Nat. Commun. 12, 6531 (2021).Article 
ADS 
CAS 
PubMed 
PubMed Central 

Google Scholar 
Bhowmick, A. et al. Structural evidence for intermediates during O2 formation in photosystem II. Nature 617, 629–636 (2023).Article 
ADS 
CAS 
PubMed 
PubMed Central 

Google Scholar 
Chen, L. X. & Yano, J. Deciphering photoinduced catalytic reaction mechanisms in natural and artificial photosynthetic systems on multiple temporal and spatial scales using X-ray probes. Chem. Rev. 124, 5421–5469 (2024).Article 
CAS 
PubMed 

Google Scholar 
Shang, H., Shao, R. & Pan, X. Advancements in understanding oxygen-evolving complex through structural models in photosystem II. The Innovation Life 2, 100068 (2024).Article 

Google Scholar 
Siegbahn, P. E. M. Structures and energetics for O2 formation in photosystem II. Acc. Chem. Res. 42, 1871–1880 (2009).Article 
CAS 
PubMed 

Google Scholar 
Cox, N. et al. Electronic structure of the oxygen-evolving complex in photosystem II prior to O-O bond formation. Science 345, 804–808 (2014).Article 
ADS 
CAS 
PubMed 

Google Scholar 
Guo, Y. et al. The open-cubane oxo-oxyl coupling mechanism dominates photosynthetic oxygen evolution: a comprehensive DFT investigation on O-O bond formation in the S4 state. Phys. Chem. Chem. Phys. 19, 13909–13923 (2017).Article 
CAS 
PubMed 

Google Scholar 
Corry, T. A. & O’Malley, P. J. Electronic–level view of O–O bond formation in nature’s water oxidizing complex. J. Phys. Chem. Lett. 11, 4221–4225 (2020).Article 
CAS 
PubMed 

Google Scholar 
Capone, M., Guidoni, L. & Narzi, D. Structural and dynamical characterization of the S4 state of the Kok-Joliot’s cycle by means of QM/MM molecular dynamics simulations. Chem. Phys. Lett. 742, 137111 (2020).Article 
CAS 

Google Scholar 
de Lichtenberg, C., Kim, C. J., Chernev, P., Debus, R. J. & Messinger, J. The exchange of the fast substrate water in the S2 state of photosystem II is limited by diffusion of bulk water through channels—implications for the water oxidation mechanism. Chem. Sci. 12, 12763–12775 (2021).Article 
PubMed 
PubMed Central 

Google Scholar 
Yamaguchi, K., Miyagawa, K., Shoji, M., Isobe, H. & Kawakami, T. Elucidation of a multiple S3 intermediates model for water oxidation in the oxygen evolving complex of photosystem II. Calcium-assisted concerted OO bond formation. Chem. Phys. Lett. 806, 140042 (2022).Article 
CAS 

Google Scholar 
Allgöwer, F., Gamiz-Hernandez, A. P., Rutherford, A. W. & Kaila, V. R. I. Molecular principles of redox-coupled protonation dynamics in photosystem II. J. Am. Chem. Soc. 144, 7171–7180 (2022).Article 
PubMed 
PubMed Central 

Google Scholar 
Song, X. & Wang, B. O–O bond formation and oxygen release in photosystem II are enhanced by spin-exchange and synergetic coordination interactions. J. Chem. Theory Comput. 19, 2684–2696 (2023).Article 
CAS 
PubMed 

Google Scholar 
Lubitz, W., Pantazis, D. A. & Cox, N. Water oxidation in oxygenic photosynthesis studied by magnetic resonance techniques. FEBS Lett. 597, 6–29 (2023).Article 
CAS 
PubMed 

Google Scholar 
Greife, P. et al. The electron-proton bottleneck of photosynthetic oxygen evolution. Nature 617, 623–628 (2023).Article 
ADS 
CAS 
PubMed 
PubMed Central 

Google Scholar 
Barber, J. A mechanism for water splitting and oxygen production in photosynthesis. Nat. Plants 3, 17041 (2017).Article 
CAS 
PubMed 

Google Scholar 
Zhang, B. & Sun, L. Why nature chose the Mn4CaO5 cluster as water-splitting catalyst in photosystem II: a new hypothesis for the mechanism of O–O bond formation. Dalton Trans. 47, 14381–14387 (2018).Article 
CAS 
PubMed 

Google Scholar 
Sproviero, E. M., Gascón, J. A., McEvoy, J. P., Brudvig, G. W. & Batista, V. S. Quantum mechanics/molecular mechanics study of the catalytic cycle of water splitting in photosystem II. J. Am. Chem. Soc. 130, 3428–3442 (2008).Article 
CAS 
PubMed 

Google Scholar 
Kawashima, K., Takaoka, T., Kimura, H., Saito, K. & Ishikita, H. O2 evolution and recovery of the water-oxidizing enzyme. Nat. Commun. 9, 1247 (2018).Article 
ADS 
PubMed 
PubMed Central 

Google Scholar 
Yamanaka, S. et al. Possible mechanisms for the O–O bond formation in oxygen evolution reaction at the CaMn4O5(H2O)4 cluster of PSII refined to 1.9Å X-ray resolution. Chem. Phys. Lett. 511, 138–145 (2011).Article 
ADS 
CAS 

Google Scholar 
Siegbahn, P. E. M. O-O bond formation in the S4 state of the oxygen-evolving complex in photosystem II. Chem. – Eur. J. 12, 9217–9227 (2006).Article 
CAS 
PubMed 

Google Scholar 
de Lichtenberg, C. et al. Assignment of the slowly exchanging substrate water of nature’s water-splitting cofactor. Proc. Natl Acad. Sci. 121, e2319374121 (2024).Article 
PubMed 
PubMed Central 

Google Scholar 
Chernev, P., Aydin, A. O., Messinger, J. On the simulation and interpretation of substrate-water exchange experiments in photosynthetic water oxidation. Photosynth. Res. https://doi.org/10.1007/s11120-024-01084-8 (2024).Siegbahn, P. E. M. Water oxidation mechanism in photosystem II, including oxidations, proton release pathways, O–O bond formation and O2 release. Biochim. Biophys. Acta Bioenerg. 1827, 1003–1019 (2013).Article 
CAS 

Google Scholar 
Li, X. & Siegbahn, P. E. M. Alternative mechanisms for O2 release and O–O bond formation in the oxygen evolving complex of photosystem II. Phys. Chem. Chem. Phys. 17, 12168–12174 (2015).Article 
CAS 
PubMed 

Google Scholar 
Shoji, M., Isobe, H., Shigeta, Y., Nakajima, T. & Yamaguchi, K. Concerted mechanism of water insertion and O2 release during the S4 to S0 transition of the oxygen-evolving complex in photosystem II. J. Phys. Chem. B 122, 6491–6502 (2018).Article 
CAS 
PubMed 

Google Scholar 
Capone, M., Narzi, D. & Guidoni, L. Mechanism of oxygen evolution and Mn4CaO5 cluster restoration in the natural water-oxidizing catalyst. Biochemistry 60, 2341–2348 (2021).Article 
CAS 
PubMed 

Google Scholar 
Krewald, V. et al. Metal oxidation states in biological water splitting. Chem. Sci. 6, 1676–1695 (2015).Article 
CAS 
PubMed 
PubMed Central 

Google Scholar 
Ames, W. et al. Theoretical evaluation of structural models of the S2 state in the oxygen evolving complex of photosystem II: protonation states and magnetic interactions. J. Am. Chem. Soc. 133, 19743–19757 (2011).Article 
CAS 
PubMed 

Google Scholar 
Robertazzi, A., Galstyan, A. & Knapp, E. W. PSII manganese cluster: protonation of W2, O5, O4 and His337 in the S1 state explored by combined quantum chemical and electrostatic energy computations. Biochim. Biophys. Acta, Bioenerg. 1837, 1316–1321 (2014).Article 
CAS 

Google Scholar 
Yamamoto, M., Nakamura, S. & Noguchi, T. Protonation structure of the photosynthetic water oxidizing complex in the S0 state as revealed by normal mode analysis using quantum mechanics/molecular mechanics calculations. Phys. Chem. Chem. Phys. 22, 24213–24225 (2020).Article 
PubMed 

Google Scholar 
Chrysina, M. et al. Nature of S-states in the oxygen-evolving complex resolved by high-energy resolution fluorescence detected X-ray absorption spectroscopy. J. Am. Chem. Soc. 145, 25579–25594 (2023).Article 
CAS 
PubMed 
PubMed Central 

Google Scholar 
Yang, K. R., Lakshmi, K. V., Brudvig, G. W. & Batista, V. S. Is deprotonation of the oxygen-evolving complex of photosystem II during the S1 → S2 transition suppressed by proton quantum delocalization? J. Am. Chem. Soc. 143, 8324–8332 (2021).Article 
CAS 
PubMed 

Google Scholar 
Retegan, M. et al. A five-coordinate Mn(IV) intermediate in biological water oxidation: spectroscopic signature and a pivot mechanism for water binding. Chem. Sci. 7, 72–84 (2016).Article 
CAS 
PubMed 

Google Scholar 
Chrysina, M. et al. Five-coordinate MnIV intermediate in the activation of nature’s water splitting cofactor. Proc. Natl Acad. Sci. USA 116, 16841–16846 (2019).Article 
ADS 
CAS 
PubMed 
PubMed Central 

Google Scholar 
Capone, M., Narzi, D., Bovi, D. & Guidoni, L. Mechanism of water delivery to the active site of photosystem II along the S2 to S3 transition. J. Phys. Chem. Lett. 7, 592–596 (2016).Article 
CAS 
PubMed 

Google Scholar 
Wang, J., Askerka, M., Brudvig, G. W. & Batista, V. S. Crystallographic data support the carousel mechanism of water supply to the oxygen-evolving complex of photosystem II. ACS Energy Lett. 2, 2299–2306 (2017).Article 
CAS 
PubMed 
PubMed Central 

Google Scholar 
Lohmiller, T., Cox, N., Su, J.-H., Messinger, J. & Lubitz, W. The basic properties of the electronic structure of the oxygen-evolving complex of photosystem II are not perturbed by Ca2+ removal. J. Biol. Chem. 287, 24721–24733 (2012).Article 
CAS 
PubMed 
PubMed Central 

Google Scholar 
Siegbahn, P. E. M. Water oxidation energy diagrams for photosystem II for different protonation states, and the effect of removing calcium. Phys. Chem. Chem. Phys. 16, 11893–11900 (2014).Article 
CAS 
PubMed 

Google Scholar 
Lohmiller, T., Shelby, M. L., Long, X., Yachandra, V. K. & Yano, J. Removal of Ca2+ from the oxygen-evolving complex in photosystem II has minimal effect on the Mn4O5 core structure: a polarized Mn X-ray absorption spectroscopy study. J. Phys. Chem. B 119, 13742–13754 (2015).Article 
CAS 
PubMed 
PubMed Central 

Google Scholar 
Kornowicz, A. et al. Fresh impetus in the chemistry of calcium peroxides. J. Am. Chem. Soc. https://doi.org/10.1021/jacs.4c00906 (2024).Vassiliev, S., Zaraiskaya, T. & Bruce, D. Exploring the energetics of water permeation in photosystem II by multiple steered molecular dynamics simulations. Biochim. Biophys. Acta Bioenerg. 1817, 1671–1678 (2012).Article 
CAS 

Google Scholar 
Retegan, M. & Pantazis, D. A. Interaction of methanol with the oxygen-evolving complex: atomistic models, channel identification, species dependence, and mechanistic implications. Chem. Sci. 7, 6463–6476 (2016).Article 
CAS 
PubMed 
PubMed Central 

Google Scholar 
Sirohiwal, A. & Pantazis, D. A. Functional water networks in fully hydrated photosystem II. J. Am. Chem. Soc. 144, 22035–22050 (2022).Article 
CAS 
PubMed 
PubMed Central 

Google Scholar 
Liu, J. et al. Water ligands regulate the redox leveling mechanism of the oxygen-evolving complex of the photosystem II. J. Am. Chem. Soc. 146, 15986–15999 (2024).Article 
CAS 
PubMed 

Google Scholar 
Hussein, R. et al. Cryo–electron microscopy reveals hydrogen positions and water networks in photosystem II. Science 384, 1349–1355 (2024).Article 
ADS 
PubMed 

Google Scholar 
Zaharieva, I. & Dau, H. Energetics and kinetics of S-State transitions monitored by delayed chlorophyll fluorescence. Front. Plant Sci. 10, 386 (2019).Article 
PubMed 
PubMed Central 

Google Scholar 
Claeyssens, F. et al. High-accuracy computation of reaction barriers in enzymes. Angew. Chem. Int. Ed. 45, 6856–6859 (2006).Article 
CAS 

Google Scholar 
Cramer, C. J. & Truhlar, D. G. Density functional theory for transition metals and transition metal chemistry. Phys. Chem. Chem. Phys. 11, 10757–10816 (2009).Article 
CAS 
PubMed 

Google Scholar 
Cheong, P. H.-Y., Legault, C. Y., Um, J. M., Çelebi-Ölçüm, N. & Houk, K. N. Quantum mechanical investigations of organocatalysis: mechanisms, reactivities, and selectivities. Chem. Rev. 111, 5042–5137 (2011).Article 
CAS 
PubMed 
PubMed Central 

Google Scholar 
Blomberg, M. R. A., Borowski, T., Himo, F., Liao, R.-Z. & Siegbahn, P. E. M. Quantum chemical studies of mechanisms for metalloenzymes. Chem. Rev. 114, 3601–3658 (2014).Article 
CAS 
PubMed 

Google Scholar 
Brunner, H. & Tsuno, T. Ligand dissociation: planar or pyramidal intermediates? Acc. Chem. Res. 42, 1501–1510 (2009).Article 
CAS 
PubMed 

Google Scholar 
Schwiedrzik, L., Rajkovic, T. & González, L. Regeneration and degradation in a biomimetic polyoxometalate water oxidation catalyst. ACS Catal. 13, 3007–3019 (2023).Article 
CAS 
PubMed 
PubMed Central 

Google Scholar 
Quagliano, J. V. & Schubert, L. E. O. The trans effect in complex inorganic compounds. Chem. Rev. 50, 201–260 (1952).Article 
CAS 

Google Scholar 
Coe, B. J. & Glenwright, S. J. Trans-effects in octahedral transition metal complexes. Coord. Chem. Rev. 203, 5–80 (2000).Article 
CAS 

Google Scholar 
Siegbahn, P. E. M. Substrate water exchange for the oxygen evolving complex in PSII in the S1, S2, and S3 states. J. Am. Chem. Soc. 135, 9442–9449 (2013).Article 
CAS 
PubMed 

Google Scholar 
de Lichtenberg, C. & Messinger, J. Substrate water exchange in the S2 state of photosystem II is dependent on the conformation of the Mn4Ca cluster. Phys. Chem. Chem. Phys. 22, 12894–12908 (2020).Article 
PubMed 

Google Scholar 
Lohmiller, T. et al. The first state in the catalytic cycle of the water-oxidizing enzyme: identification of a water-derived μ-hydroxo bridge. J. Am. Chem. Soc. 139, 14412–14424 (2017).Article 
CAS 
PubMed 

Google Scholar 
Robblee, J. H. et al. The Mn cluster in the S0 state of the oxygen-evolving complex of photosystem II studied by EXAFS spectroscopy: are there three di-μ-oxo-bridged Mn2 moieties in the tetranuclear Mn complex? J. Am. Chem. Soc. 124, 7459–7471 (2002).Article 
CAS 
PubMed 
PubMed Central 

Google Scholar 
Yano, J. & Yachandra, V. Mn4Ca cluster in photosynthesis: where and how water is oxidized to dioxygen. Chem. Rev. 114, 4175–4205 (2014).Article 
CAS 
PubMed 
PubMed Central 

Google Scholar 
Drosou, M., Zahariou, G. & Pantazis, D. A. Orientational Jahn–Teller isomerism in the dark-stable state of nature’s water oxidase. Angew. Chem. Int. Ed. 60, 13493–13499 (2021).Article 
CAS 

Google Scholar 
Pantazis, D. A., Ames, W., Cox, N., Lubitz, W. & Neese, F. Two interconvertible structures that explain the spectroscopic properties of the oxygen-evolving complex of photosystem II in the S2 state. Angew. Chem. Int. Ed. 51, 9935–9940 (2012).Article 
CAS 

Google Scholar 
Bhowmick, A. et al. Going around the Kok cycle of the water oxidation reaction with femtosecond X-ray crystallography. IUCr J 10, 642–655 (2023).Article 
CAS 

Google Scholar 
Messinger, J., Nugent, J. H. A. & Evans, M. C. W. Detection of an EPR multiline signal for the S0* state in photosystem II. Biochemistry 36, 11055–11060 (1997).Article 
CAS 
PubMed 

Google Scholar 
Åhrling, K. A., Peterson, S. & Styring, S. An oscillating manganese electron paramagnetic resonance signal from the S0 state of the oxygen evolving complex in photosystem II. Biochemistry 36, 13148–13152 (1997).Article 
PubMed 

Google Scholar 
Messinger, J. et al. The S0 state of the oxygen-evolving complex in photosystem II Is paramagnetic: detection of an EPR multiline signal. J. Am. Chem. Soc. 119, 11349–11350 (1997).Article 
CAS 
PubMed 
PubMed Central 

Google Scholar 
Åhrling, K. A., Peterson, S. & Styring, S. The S0 state EPR signal from the Mn cluster in photosystem II arises from an isolated S=1/2 ground state. Biochemistry 37, 8115–8120 (1998).Article 
PubMed 

Google Scholar 
Boussac, A., Kuhl, H., Ghibaudi, E., Rögner, M. & Rutherford, A. W. Detection of an electron paramagnetic resonance signal in the S0 state of the manganese complex of photosystem II from Synechococcus elongatus. Biochemistry 38, 11942–11948 (1999).Article 
CAS 
PubMed 

Google Scholar 
Boussac, A., Sugiura, M., Inoue, Y. & Rutherford, A. W. EPR study of the oxygen evolving complex in His-tagged photosystem II from the Cyanobacterium Synechococcus elongatus. Biochemistry 39, 13788–13799 (2000).Article 
CAS 
PubMed 

Google Scholar 
Cox, N., Pantazis, D. A. & Lubitz, W. Current understanding of the mechanism of water oxidation in photosystem II and its relation to XFEL data. Annu. Rev. Biochem. 89, 19.11–19.26 (2020).Article 

Google Scholar 
Cox, N. & Messinger, J. Reflections on substrate water and dioxygen formation. Biochim. Biophys. Acta, Bioenerg. 1827, 1020–1030 (2013).Article 
CAS 

Google Scholar 
Kosaki, S. & Mino, H. Molecular structure related to an S = 5/2 high-spin S2 state manganese cluster of photosystem II investigated by Q-band pulse EPR spectroscopy. J. Phys. Chem. B 127, 6441–6448 (2023).Article 
CAS 
PubMed 

Google Scholar 
Saito, K., Mino, H., Nishio, S. & Ishikita, H. Protonation structure of the closed-cubane conformation of the O2-evolving complex in photosystem II. PNAS Nexus 1, 1–14 (2022).Article 
CAS 

Google Scholar 
Barchenko, M. & O’Malley, P. J. A reappraisal of the S2 State of nature’s water oxidizing complex in Its low and high spin forms. J. Phys. Chem. Lett. 15, 5883–5886 (2024).Article 
CAS 
PubMed 
PubMed Central 

Google Scholar 
Li, H. et al. Capturing structural changes of the S1 to S2 transition of photosystem II using time-resolved serial femtosecond crystallography. IUCrJ 8, 431–443 (2021).Article 
PubMed 
PubMed Central 

Google Scholar 
Li, H. et al. Oxygen-evolving photosystem II structures during S1–S2–S3 transitions. Nature 626, 670–677 (2024).Article 
ADS 
CAS 
PubMed 
PubMed Central 

Google Scholar 
Isobe, H., Shoji, M., Suzuki, T., Shen, J.-R. & Yamaguchi, K. Spin, valence, and structural isomerism in the S3 State of the oxygen-evolving complex of photosystem II as a manifestation of multimetallic cooperativity. J. Chem. Theory Comput. 15, 2375–2391 (2019).Article 
CAS 
PubMed 

Google Scholar 
Seritan, S. et al. TeraChem: A graphical processing unit-accelerated electronic structure package for large-scale ab initio molecular dynamics. WIREs Comput Mol. Sci. 11, e1494 (2020).Article 

Google Scholar 
Retegan, M., Neese, F. & Pantazis, D. A. Convergence of QM/MM and cluster models for the spectroscopic properties of the oxygen-evolving complex in photosystem II. J. Chem. Theory Comput. 9, 3832–3842 (2013).Article 
CAS 
PubMed 

Google Scholar 
Siegbahn, P. E. M. & Blomberg, M. R. A. Energy diagrams for water oxidation in photosystem II using different density functionals. J. Chem. Theory Comput. 10, 268–272 (2014).Article 
CAS 
PubMed 

Google Scholar 
Frisch, M.J. et al. Gaussian 16 Rev. C.01. (Wallingford, CT, 2019).Thom, A. J. W., Sundstrom, E. J. & Head-Gordon, M. LOBA: a localized orbital bonding analysis to calculate oxidation states, with application to a model water oxidation catalyst. Phys. Chem. Chem. Phys. 11, 11297–11304 (2009).Article 
CAS 
PubMed 

Google Scholar 
Lu, T. & Chen, F. Multiwfn: a multifunctional wavefunction analyzer. J. Comput. Chem. 33, 580–592 (2012).Article 
PubMed 

Google Scholar 
Cheah, M. H. et al. Assessment of the manganese cluster’s oxidation state via photoactivation of photosystem II microcrystals. Proc. Natl Acad. Sci. USA 117, 141–145 (2020).Article 
ADS 
CAS 
PubMed 

Google Scholar 
Capone, M., Bovi, D., Narzi, D. & Guidoni, L. Reorganization of substrate waters between the closed and open cubane conformers during the S2 to S3 transition in the oxygen evolving complex. Biochemistry 54, 6439–6442 (2015).Article 
CAS 
PubMed 

Google Scholar 
Isobe, H., Shoji, M., Suzuki, T., Shen, J.-R. & Yamaguchi, K. Exploring reaction pathways for the structural rearrangements of the Mn cluster induced by water binding in the S3 state of the oxygen evolving complex of photosystem II. J. Photochem. Photobiol. A 405, 112905 (2021).Article 
CAS 

Google Scholar 
Guo, Y., Messinger, J., Kloo, L. & Sun, L. Reversible structural isomerization of nature’s water oxidation catalyst prior to O–O bond formation. J. Am. Chem. Soc. 144, 11736–11747 (2022).Article 
CAS 
PubMed 
PubMed Central 

Google Scholar 
Pushkar, Y., Davis, K. M. & Palenik, M. C. Model of the oxygen evolving complex which is highly predisposed to O-O bond formation. J. Phys. Chem. Lett. 9, 3525–3531 (2018).Article 
CAS 
PubMed 

Google Scholar 
Shoji, M., Isobe, H. & Yamaguchi, K. Concerted bond switching mechanism coupled with one-electron transfer for the oxygen-oxygen bond formation in the oxygen-evolving complex of photosystem II. Chem. Phys. Lett. 714, 219–226 (2019).Article 
ADS 
CAS 

Google Scholar 
Rummel, F. & O’Malley, P. J. How nature makes O2: an electronic level mechanism for water oxidation in photosynthesis. J. Phys. Chem. B 126, 8214–8221 (2022).Article 
CAS 
PubMed 
PubMed Central 

Google Scholar 
Rummel, F., Malcomson, T., Barchenko, M. & O’Malley, P. J. Insights into PSII’s S3YZ• state: an electronic and magnetic analysis. J. Phys. Chem. Lett. 15, 499–506 (2024).Article 
CAS 
PubMed 
PubMed Central 

Google Scholar 
Krewald, V., Neese, F. & Pantazis, D. A. Implications of structural heterogeneity for the electronic structure of the final oxygen-evolving intermediate in photosystem II. J. Inorg. Biochem. 199, 110797 (2019).Article 
CAS 
PubMed 

Google Scholar 
Guo, Y., Messinger, J., Kloo, L. & Sun, L. Alternative mechanism for O2 formation in natural photosynthesis via nucleophilic oxo–oxo coupling. J. Am. Chem. Soc. 145, 4129–4141 (2023).Article 
CAS 

Google Scholar 
Ariafard, A., Longhurst, M., Swiegers, G. & Stranger, R. Mechanisms of Mn(V)-oxo to Mn(IV)-oxyl conversion: from closed-cubane photosystem II to Mn(V) catalysts and the role of the entering ligands. Chem. – Eur. J. 30, e202400396 (2024).Article 
CAS 
PubMed 

Google Scholar 
Nakamura, S. & Noguchi, T. Quantum mechanics/molecular mechanics simulation of the ligand vibrations of the water-oxidizing Mn4CaO5 cluster in photosystem II. Proc. Natl Acad. Sci. USA 113, 12727–12732 (2016).Article 
ADS 
CAS 
PubMed 
PubMed Central 

Google Scholar 
Huo, P.-Y., Jiang, W.-Z., Yang, R.-Y. & Zhang, X.-R. Dynamic evolution of S0-S3 at the oxygen-evolving complex with spin markers under photoelectric polarization. Phys. Rev. Appl. 21, 024024 (2024).Article 
ADS 
CAS 

Google Scholar 
Saito, K., Rutherford, A. W. & Ishikita, H. Energetics of proton release on the first oxidation step in the water-oxidizing enzyme. Nat. Commun. 6, 8488 (2015).Article 
ADS 
CAS 
PubMed 

Google Scholar 
Corry, T. A. & O’Malley, P. J. S3 state models of nature’s water oxidizing complex: analysis of bonding and magnetic exchange pathways, assessment of experimental electron paramagnetic resonance data, and Implications for the water oxidation mechanism. J. Phys. Chem. B 125, 10097–10107 (2021).Article 
CAS 
PubMed 

Google Scholar 

Hot Topics

Related Articles