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Yamaguchi K, Shoji M, Isobe H, Kawakami T, Miyagawa K, Suga M, Akita F, Shen JR. Geometric, electronic and spin structures of the CaMn4O5 catalyst for water oxidation in oxygen-evolving photosystem II. Interplay between experiments and theoretical computations. Coord Chem Rev 2022. [DOI: 10.1016/j.ccr.2022.214742] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
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Petrie S, Terrett R, Stranger R, Pace RJ. Rationalizing the Geometries of the Water Oxidising Complex in the Atomic Resolution, Nominal S 3 State Crystal Structures of Photosystem II. Chemphyschem 2020; 21:785-801. [PMID: 32133758 DOI: 10.1002/cphc.201901106] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/18/2019] [Revised: 01/14/2020] [Indexed: 11/06/2022]
Abstract
Three atomic resolution crystal structures of Photosystem II, in the double flashed, nominal S3 intermediate state of its Mn4 Ca Water Oxidising Complex (WOC), have now been presented, at 2.25, 2.35 and 2.08 Å resolution. Although very similar overall, the S3 structures differ within the WOC catalytic site. The 2.25 Å structure contains only one oxy species (O5) in the WOC cavity, weakly associated with Mn centres, similar to that in the earlier 1.95 Å S1 structure. The 2.35 Å structure shows two such species (O5, O6), with the Mn centres and O5 positioned as in the 2.25 Å structure and O5-O6 separation of ∼1.5 Å. In the latest S3 variant, two oxy species are also seen (O5, Ox), with the Ox group appearing only in S3 , closely ligating one Mn, with O5-Ox separation <2.1 Å. The O5 and O6/Ox groups were proposed to be substrate water derived species. Recently, Petrie et al. (Chem. Phys. Chem., 2017) presented large scale Quantum Chemical modelling of the 2.25 Å structure, quantitatively explaining all significant features within the WOC region. This, as in our earlier studies, assumed a 'low' Mn oxidation paradigm (mean S1 Mn oxidation level of +3.0, Petrie et al., Angew. Chem. Int. Ed., 2015), rather than a 'high' oxidation model (mean S1 oxidation level of +3.5). In 2018 we showed (Chem. Phys. Chem., 2018) this oxidation state assumption predicted two energetically close S3 structural forms, one with the metal centres and O5 (as OH- ) positioned as in the 2.25 Å structure, and the other with the metals similarly placed, but with O5 (as H2 O) located in the O6 position of the 2.35 Å structure. The 2.35 Å two flashed structure was likely a crystal superposition of two such forms. Here we show, by similar computational analysis, that the latest 2.08 Å S3 structure is also a likely superposition of forms, but with O5 (as OH- ) occupying either the O5 or Ox positions in the WOC cavity. This highlights a remarkable structural 'lability' of the WOC centre in the S3 state, which is likely catalytically relevant to its water splitting function.
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Affiliation(s)
- Simon Petrie
- Research School of Chemistry, College of Physical and Mathematical Sciences, The Australian National University, Acton, ACT 2601, Australia
| | - Richard Terrett
- Research School of Chemistry, College of Physical and Mathematical Sciences, The Australian National University, Acton, ACT 2601, Australia
| | - Robert Stranger
- Research School of Chemistry, College of Physical and Mathematical Sciences, The Australian National University, Acton, ACT 2601, Australia
| | - Ron J Pace
- Research School of Chemistry, College of Physical and Mathematical Sciences, The Australian National University, Acton, ACT 2601, Australia
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Miyagawa K, Kawakami T, Suzuki Y, Isobe H, Shoji M, Yamanaka S, Okumura M, Nakajima T, Yamaguchi K. Domain-based local pair natural orbital CCSD(T) calculations of strongly correlated electron systems: Examination of dynamic equilibrium models based on multiple intermediates in S1 state of photosystem II. Mol Phys 2019. [DOI: 10.1080/00268976.2019.1666171] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
Affiliation(s)
- K. Miyagawa
- Institute for Scientific and Industrial Research, Osaka University, Osaka 567-0047, Japan
| | - T. Kawakami
- Graduate School of Science, Osaka University, Toyonaka 560-0043, Japan
- RIKEN Center for Computational Science, Kobe, Hyogo 650-0047, Japan
| | - Y. Suzuki
- Graduate School of Science, Osaka University, Toyonaka 560-0043, Japan
| | - H. Isobe
- Graduate School of Natural Science and Technology, Okayama University, Okayama 700-8530, Japan
| | - M. Shoji
- Center of Computational Sciences, Tsukuba University, Tsukuba, Ibaraki 305-8577, Japan
| | - S. Yamanaka
- Graduate School of Science, Osaka University, Toyonaka 560-0043, Japan
| | - M. Okumura
- Graduate School of Science, Osaka University, Toyonaka 560-0043, Japan
| | - T. Nakajima
- RIKEN Center for Computational Science, Kobe, Hyogo 650-0047, Japan
| | - K. Yamaguchi
- Institute for Scientific and Industrial Research, Osaka University, Osaka 567-0047, Japan
- RIKEN Center for Computational Science, Kobe, Hyogo 650-0047, Japan
- Insitute for Nanoscience Design, Osaka University, Toyonaka 560-0043, Japan
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Abstract
AbstractCyanobacteria and plants carry out oxygenic photosynthesis. They use water to generate the atmospheric oxygen we breathe and carbon dioxide to produce the biomass serving as food, feed, fibre and fuel. This paper scans the emergence of structural and mechanistic understanding of oxygen evolution over the past 50 years. It reviews speculative concepts and the stepped insight provided by novel experimental and theoretical techniques. Driven by sunlight photosystem II oxidizes the catalyst of water oxidation, a hetero-metallic Mn4CaO5(H2O)4 cluster. Mn3Ca are arranged in cubanoid and one Mn dangles out. By accumulation of four oxidizing equivalents before initiating dioxygen formation it matches the four-electron chemistry from water to dioxygen to the one-electron chemistry of the photo-sensitizer. Potentially harmful intermediates are thereby occluded in space and time. Kinetic signatures of the catalytic cluster and its partners in the photo-reaction centre have been resolved, in the frequency domain ranging from acoustic waves via infra-red to X-ray radiation, and in the time domain from nano- to milli-seconds. X-ray structures to a resolution of 1.9 Å are available. Even time resolved X-ray structures have been obtained by clocking the reaction cycle by flashes of light and diffraction with femtosecond X-ray pulses. The terminal reaction cascade from two molecules of water to dioxygen involves the transfer of four electrons, two protons, one dioxygen and one water. A rigorous mechanistic analysis is challenging because of the kinetic enslaving at millisecond duration of six partial reactions (4e−, 1H+, 1O2). For the time being a peroxide-intermediate in the reaction cascade to dioxygen has been in focus, both experimentally and by quantum chemistry. Homo sapiens has relied on burning the products of oxygenic photosynthesis, recent and fossil. Mankind's total energy consumption amounts to almost one-fourth of the global photosynthetic productivity. If the average power consumption equalled one of those nations with the highest consumption per capita it was four times greater and matched the total productivity. It is obvious that biomass should be harvested for food, feed, fibre and platform chemicals rather than for fuel.
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Shoji M, Isobe H, Yamanaka S, Umena Y, Kawakami K, Kamiya N, Yamaguchi K. Theoretical Elucidation of Geometrical Structures of the CaMn4O5 Cluster in Oxygen Evolving Complex of Photosystem II Scope and Applicability of Estimation Formulae of Structural Deformations via the Mixed-Valence and Jahn–Teller Effects. ADVANCES IN QUANTUM CHEMISTRY 2019. [DOI: 10.1016/bs.aiq.2018.05.003] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
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Petrie S, Stranger R, Pace RJ. Explaining the Different Geometries of the Water Oxidising Complex in the Nominal S 3 State Crystal Structures of Photosystem II at 2.25 Å and 2.35 Å. Chemphyschem 2018; 19:3296-3309. [PMID: 30290080 DOI: 10.1002/cphc.201800686] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/17/2018] [Indexed: 11/10/2022]
Abstract
Recently two atomic resolution crystal structures of Photosystem II, in the double flashed, nominal S3 intermediate state of its Mn4 Ca water oxidising complex (WOC), have been presented (Young et al., Nature 2016, 540, 453; Suga et al., Nature 2017, 543, 131). These structures are at 2.25 Å and 2.35 Å resolution, respectively. Although highly similar in most respects, the structures differ in a key region within the WOC catalytic site. In the 2.25 Å structure, one oxy species (O5) is observed within the WOC cavity, weakly associated with the Mn centres, similar to that seen earlier in the 1.95 Å XRD structure of the S1 intermediate (Suga et al., Nature, 2015, 517, 99). In the 2.35 Å structure, two such species are seen (O5, O6), with the Mn centres and O5 positioned as in the 2.25 Å structure and an O5-O6 separation of ∼1.5 Å, consistent with peroxo formation. This suggests O5 and O6 are substrate water derived species in this double flashed form. Recently we have presented (Petrie, et al., Chem. Phys. Chem., 2017) a large scale (220 atom) quantum chemical model of the Young et al. 2.25 Å structure, which quantitatively explains all significant features within the WOC region of that structure, particularly the positions of the metal centres and O5 group. Critical to this was our assumption of a 'low' Mn oxidation paradigm (mean S1 Mn oxidation level of +3.0, Petrie et al., Angew. Chem. Int. Ed., 2015), rather than a 'high' oxidation model (mean S1 oxidation level of +3.5), widely assumed in the literature. Here we show that our same oxidation state model predicts two classes of energetically close S3 structural forms, analogous to the S1 state, one with the metal centres and O5 positioned as in the 2.25 Å structure, and the other with the metals similarly placed, but with O5 located in the O6 position of the 2.35 Å structure. We show that the Suga et al. 2.35 Å structure is likely a superposition of two such forms, one from each class, which is consistent with reported atomic occupancies for that structure and the relative total energies we calculate for the two structural forms.
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Affiliation(s)
- Simon Petrie
- Research School of Chemistry, College of Physical and Mathematical Sciences, The Australian National University, Acton ACT, Australia, 2601
| | - Robert Stranger
- Research School of Chemistry, College of Physical and Mathematical Sciences, The Australian National University, Acton ACT, Australia, 2601
| | - Ron J Pace
- Research School of Chemistry, College of Physical and Mathematical Sciences, The Australian National University, Acton ACT, Australia, 2601
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Affiliation(s)
- Dimitrios A. Pantazis
- Max-Planck-Institut für Kohlenforschung, Kaiser-Wilhelm-Platz 1, 45470 Mülheim an der Ruhr, Germany
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Petrie S, Stranger R, Pace RJ. Rationalizing the 2.25 Å Resolution Crystal Structure of the Water Oxidising Complex of Photosystem II in the S3State. Chemphyschem 2017; 18:2924-2931. [DOI: 10.1002/cphc.201700640] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/08/2017] [Indexed: 12/14/2022]
Affiliation(s)
- Simon Petrie
- Research School of Chemistry, College of Physical and Mathematical Sciences; The Australian National University; Acton ACT 2601 Australia
| | - Rob Stranger
- Research School of Chemistry, College of Physical and Mathematical Sciences; The Australian National University; Acton ACT 2601 Australia
| | - Ron J. Pace
- Research School of Chemistry, College of Physical and Mathematical Sciences; The Australian National University; Acton ACT 2601 Australia
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9
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Rossini E, Knapp EW. Protonation equilibria of transition metal complexes: From model systems toward the Mn-complex in photosystem II. Coord Chem Rev 2017. [DOI: 10.1016/j.ccr.2017.02.017] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
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10
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Yamaguchi K, Shoji M, Isobe H, Yamanaka S, Umena Y, Kawakami K, Kamiya N. On the guiding principles for understanding of geometrical structures of the CaMn4O5 cluster in oxygen-evolving complex of photosystem II. Proposal of estimation formula of structural deformations via the Jahn–Teller effects. Mol Phys 2017. [DOI: 10.1080/00268976.2016.1278476] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022]
Affiliation(s)
- K. Yamaguchi
- Institute for Nanoscience Design, Osaka University, Toyonaka, Japan
- Handairigaku Techno-Research , Toyonaka, Japan
| | - M. Shoji
- Center of Computational Sciences, Tsukuba University , Tsukuba, Japan
| | - H. Isobe
- Graduate School of Natural Science and Technology, Okayama University , Okayama, Japan
| | - S. Yamanaka
- Graduate School of Science, Osaka University , Osaka, Japan
| | - Y. Umena
- The OUC Advanced Research Institute for Natural Science and Technology (OCARNA), Osaka City University , Osaka, Japan
| | - K. Kawakami
- The OUC Advanced Research Institute for Natural Science and Technology (OCARNA), Osaka City University , Osaka, Japan
| | - N. Kamiya
- The OUC Advanced Research Institute for Natural Science and Technology (OCARNA), Osaka City University , Osaka, Japan
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Najafpour MM, Heidari S, Balaghi SE, Hołyńska M, Sadr MH, Soltani B, Khatamian M, Larkum AW, Allakhverdiev SI. Proposed mechanisms for water oxidation by Photosystem II and nanosized manganese oxides. BIOCHIMICA ET BIOPHYSICA ACTA-BIOENERGETICS 2017; 1858:156-174. [DOI: 10.1016/j.bbabio.2016.11.007] [Citation(s) in RCA: 35] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/15/2016] [Revised: 11/05/2016] [Accepted: 11/08/2016] [Indexed: 12/18/2022]
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12
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Chernev P, Zaharieva I, Rossini E, Galstyan A, Dau H, Knapp EW. Merging Structural Information from X-ray Crystallography, Quantum Chemistry, and EXAFS Spectra: The Oxygen-Evolving Complex in PSII. J Phys Chem B 2016; 120:10899-10922. [DOI: 10.1021/acs.jpcb.6b05800] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Affiliation(s)
- Petko Chernev
- Institute of Chemistry and Biochemistry and ‡Department of Physics, Freie Universität Berlin, D-14195 Berlin, Germany
| | - Ivelina Zaharieva
- Institute of Chemistry and Biochemistry and ‡Department of Physics, Freie Universität Berlin, D-14195 Berlin, Germany
| | - Emanuele Rossini
- Institute of Chemistry and Biochemistry and ‡Department of Physics, Freie Universität Berlin, D-14195 Berlin, Germany
| | - Artur Galstyan
- Institute of Chemistry and Biochemistry and ‡Department of Physics, Freie Universität Berlin, D-14195 Berlin, Germany
| | - Holger Dau
- Institute of Chemistry and Biochemistry and ‡Department of Physics, Freie Universität Berlin, D-14195 Berlin, Germany
| | - Ernst-Walter Knapp
- Institute of Chemistry and Biochemistry and ‡Department of Physics, Freie Universität Berlin, D-14195 Berlin, Germany
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Yamaguchi K, Isobe H, Shoji M, Yamanaka S, Okumura M. Theory of chemical bonds in metalloenzymes XX: magneto-structural correlations in the CaMn4O5cluster in oxygen-evolving complex of photosystem II. Mol Phys 2015. [DOI: 10.1080/00268976.2015.1114162] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022]
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14
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Shoji M, Isobe H, Nakajima T, Yamaguchi K. Full geometry optimizations of the CaMn4O4 model cluster for the oxygen evolving complex of photosystem II. Chem Phys Lett 2015. [DOI: 10.1016/j.cplett.2015.10.006] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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15
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Krewald V, Neese F, Pantazis DA. Resolving the Manganese Oxidation States in the Oxygen-evolving Catalyst of Natural Photosynthesis. Isr J Chem 2015. [DOI: 10.1002/ijch.201500051] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/10/2023]
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16
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Shoji M, Isobe H, Yamanaka S, Suga M, Akita F, Shen JR, Yamaguchi K. On the guiding principles for lucid understanding of the damage-free S1 structure of the CaMn4O5 cluster in the oxygen evolving complex of photosystem II. Chem Phys Lett 2015. [DOI: 10.1016/j.cplett.2015.03.033] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
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17
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Petrie S, Pace RJ, Stranger R. Resolving the Differences Between the 1.9 Å and 1.95 Å Crystal Structures of Photosystem II: A Single Proton Relocation Defines Two Tautomeric Forms of the Water-Oxidizing Complex. Angew Chem Int Ed Engl 2015. [DOI: 10.1002/ange.201502463] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
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18
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Petrie S, Pace RJ, Stranger R. Resolving the Differences Between the 1.9 Å and 1.95 Å Crystal Structures of Photosystem II: A Single Proton Relocation Defines Two Tautomeric Forms of the Water-Oxidizing Complex. Angew Chem Int Ed Engl 2015; 54:7120-4. [PMID: 25917648 DOI: 10.1002/anie.201502463] [Citation(s) in RCA: 35] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/17/2015] [Indexed: 11/11/2022]
Abstract
Great progress has been made in characterizing the water-oxidizing complex (WOC) in photosystem II (PSII) with the publication of a 1.9 Å resolution X-ray diffraction (XRD) and recently a 1.95 Å X-ray free-electron laser (XFEL) structure. However, these achievements are under threat because of perceived conflicts with other experimental data. For the earlier 1.9 Å structure, lack of agreement with extended X-ray absorption fine structure (EXAFS) data led to the notion that the WOC suffered from X-ray photoreduction. In the recent 1.95 Å structure, Mn photoreduction is not an issue, but poor agreement with computational models which adopt the 'high' oxidation state paradigm, has again resulted in criticism of the structure on the basis of contamination with lower S states of the WOC. Here we use DFT modeling to show that the distinct WOC geometries in the 1.9 and 1.95 Å structures can be straightforwardly accounted for when the Mn oxidation states are consistent with the 'low' oxidation state paradigm. Remarkably, our calculations show that the two structures are tautomers, related by a single proton relocation.
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Affiliation(s)
- Simon Petrie
- Research School of Chemistry, Australian National University, Canberra ACT 0200 (Australia)
| | - Ron J Pace
- Research School of Chemistry, Australian National University, Canberra ACT 0200 (Australia).
| | - Rob Stranger
- Research School of Chemistry, Australian National University, Canberra ACT 0200 (Australia).
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Fernando A, Weerawardene KLDM, Karimova NV, Aikens CM. Quantum Mechanical Studies of Large Metal, Metal Oxide, and Metal Chalcogenide Nanoparticles and Clusters. Chem Rev 2015; 115:6112-216. [PMID: 25898274 DOI: 10.1021/cr500506r] [Citation(s) in RCA: 217] [Impact Index Per Article: 24.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Affiliation(s)
- Amendra Fernando
- Department of Chemistry, Kansas State University, Manhattan, Kansas 66506, United States
| | | | - Natalia V Karimova
- Department of Chemistry, Kansas State University, Manhattan, Kansas 66506, United States
| | - Christine M Aikens
- Department of Chemistry, Kansas State University, Manhattan, Kansas 66506, United States
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Isobe H, Shoji M, Yamanaka S, Mino H, Umena Y, Kawakami K, Kamiya N, Shen JR, Yamaguchi K. Generalized approximate spin projection calculations of effective exchange integrals of the CaMn4O5 cluster in the S1 and S3 states of the oxygen evolving complex of photosystem II. Phys Chem Chem Phys 2015; 16:11911-23. [PMID: 24632787 DOI: 10.1039/c4cp00282b] [Citation(s) in RCA: 46] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
Full geometry optimizations followed by the vibrational analysis were performed for eight spin configurations of the CaMn4O4X(H2O)3Y (X = O, OH; Y = H2O, OH) cluster in the S1 and S3 states of the oxygen evolution complex (OEC) of photosystem II (PSII). The energy gaps among these configurations obtained by vertical, adiabatic and adiabatic plus zero-point-energy (ZPE) correction procedures have been used for computation of the effective exchange integrals (J) in the spin Hamiltonian model. The J values are calculated by the (1) analytical method and the (2) generalized approximate spin projection (AP) method that eliminates the spin contamination errors of UB3LYP solutions. Using J values derived from these methods, exact diagonalization of the spin Hamiltonian matrix was carried out, yielding excitation energies and spin densities of the ground and lower-excited states of the cluster. The obtained results for the right (R)- and left (L)-opened structures in the S1 and S3 states are found to be consistent with available optical and magnetic experimental results. Implications of the computational results are discussed in relation to (a) the necessity of the exact diagonalization for computations of reliable energy levels, (b) magneto-structural correlations in the CaMn4O5 cluster of the OEC of PSII, (c) structural symmetry breaking in the S1 and S3 states, and (d) the right- and left-handed scenarios for the O-O bond formation for water oxidation.
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Affiliation(s)
- H Isobe
- Graduate School of Natural Science and Technology, Okayama University, Okayama 700-8530, Japan
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21
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Petrie S, Stranger R, Pace RJ. Rationalising the Geometric Variation between the A and B Monomers in the 1.9 Å Crystal Structure of Photosystem II. Chemistry 2015; 21:6780-92. [DOI: 10.1002/chem.201406419] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/10/2014] [Indexed: 11/12/2022]
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Davis KM, Pushkar YN. Structure of the Oxygen Evolving Complex of Photosystem II at Room Temperature. J Phys Chem B 2015; 119:3492-8. [PMID: 25621994 DOI: 10.1021/acs.jpcb.5b00452] [Citation(s) in RCA: 36] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Katherine M. Davis
- Department of Physics and Astronomy, Purdue University, 525 Northwestern Avenue, West Lafayette, Indiana 47907, United States
| | - Yulia N. Pushkar
- Department of Physics and Astronomy, Purdue University, 525 Northwestern Avenue, West Lafayette, Indiana 47907, United States
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23
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Krewald V, Retegan M, Cox N, Messinger J, Lubitz W, DeBeer S, Neese F, Pantazis DA. Metal oxidation states in biological water splitting. Chem Sci 2015; 6:1676-1695. [PMID: 29308133 PMCID: PMC5639794 DOI: 10.1039/c4sc03720k] [Citation(s) in RCA: 230] [Impact Index Per Article: 25.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2014] [Accepted: 12/31/2014] [Indexed: 12/20/2022] Open
Abstract
A central question in biological water splitting concerns the oxidation states of the manganese ions that comprise the oxygen-evolving complex of photosystem II.
A central question in biological water splitting concerns the oxidation states of the manganese ions that comprise the oxygen-evolving complex of photosystem II. Understanding the nature and order of oxidation events that occur during the catalytic cycle of five Si states (i = 0–4) is of fundamental importance both for the natural system and for artificial water oxidation catalysts. Despite the widespread adoption of the so-called “high-valent scheme”—where, for example, the Mn oxidation states in the S2 state are assigned as III, IV, IV, IV—the competing “low-valent scheme” that differs by a total of two metal unpaired electrons (i.e. III, III, III, IV in the S2 state) is favored by several recent studies for the biological catalyst. The question of the correct oxidation state assignment is addressed here by a detailed computational comparison of the two schemes using a common structural platform and theoretical approach. Models based on crystallographic constraints were constructed for all conceivable oxidation state assignments in the four (semi)stable S states of the oxygen evolving complex, sampling various protonation levels and patterns to ensure comprehensive coverage. The models are evaluated with respect to their geometric, energetic, electronic, and spectroscopic properties against available experimental EXAFS, XFEL-XRD, EPR, ENDOR and Mn K pre-edge XANES data. New 2.5 K 55Mn ENDOR data of the S2 state are also reported. Our results conclusively show that the entire S state phenomenology can only be accommodated within the high-valent scheme by adopting a single motif and protonation pattern that progresses smoothly from S0 (III, III, III, IV) to S3 (IV, IV, IV, IV), satisfying all experimental constraints and reproducing all observables. By contrast, it was impossible to construct a consistent cycle based on the low-valent scheme for all S states. Instead, the low-valent models developed here may provide new insight into the over-reduced S states and the states involved in the assembly of the catalytically active water oxidizing cluster.
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Affiliation(s)
- Vera Krewald
- Max Planck Institute for Chemical Energy Conversion , Stiftstr. 34-38 , 45470 Mülheim an der Ruhr , Germany .
| | - Marius Retegan
- Max Planck Institute for Chemical Energy Conversion , Stiftstr. 34-38 , 45470 Mülheim an der Ruhr , Germany .
| | - Nicholas Cox
- Max Planck Institute for Chemical Energy Conversion , Stiftstr. 34-38 , 45470 Mülheim an der Ruhr , Germany .
| | - Johannes Messinger
- Department of Chemistry , Chemical Biological Center (KBC) , Umeå University , 90187 Umeå , Sweden
| | - Wolfgang Lubitz
- Max Planck Institute for Chemical Energy Conversion , Stiftstr. 34-38 , 45470 Mülheim an der Ruhr , Germany .
| | - Serena DeBeer
- Max Planck Institute for Chemical Energy Conversion , Stiftstr. 34-38 , 45470 Mülheim an der Ruhr , Germany .
| | - Frank Neese
- Max Planck Institute for Chemical Energy Conversion , Stiftstr. 34-38 , 45470 Mülheim an der Ruhr , Germany .
| | - Dimitrios A Pantazis
- Max Planck Institute for Chemical Energy Conversion , Stiftstr. 34-38 , 45470 Mülheim an der Ruhr , Germany .
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Abstract
Nature relies on a unique and intricate biochemical setup to achieve sunlight-driven water splitting. Combined experimental and computational efforts have produced significant insights into the structural and functional principles governing the operation of the water-oxidizing enzyme Photosystem II in general, and of the oxygen-evolving manganese-calcium cluster at its active site in particular. Here we review the most important aspects of biological water oxidation, emphasizing current knowledge on the organization of the enzyme, the geometric and electronic structure of the catalyst, and the role of calcium and chloride cofactors. The combination of recent experimental work on the identification of possible substrate sites with computational modeling have considerably limited the possible mechanistic pathways for the critical O-O bond formation step. Taken together, the key features and principles of natural photosynthesis may serve as inspiration for the design, development, and implementation of artificial systems.
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Shoji M, Isobe H, Yamanaka S, Umena Y, Kawakami K, Kamiya N, Shen JR, Nakajima T, Yamaguchi K. Large-Scale QM/MM Calculations of Hydrogen Bonding Networks for Proton Transfer and Water Inlet Channels for Water Oxidation—Theoretical System Models of the Oxygen-Evolving Complex of Photosystem II. ADVANCES IN QUANTUM CHEMISTRY 2015. [DOI: 10.1016/bs.aiq.2014.10.001] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
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26
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Shen JR. The Structure of Photosystem II and the Mechanism of Water Oxidation in Photosynthesis. ANNUAL REVIEW OF PLANT BIOLOGY 2015; 66:23-48. [PMID: 25746448 DOI: 10.1146/annurev-arplant-050312-120129] [Citation(s) in RCA: 442] [Impact Index Per Article: 49.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/20/2023]
Abstract
Oxygenic photosynthesis forms the basis of aerobic life on earth by converting light energy into biologically useful chemical energy and by splitting water to generate molecular oxygen. The water-splitting and oxygen-evolving reaction is catalyzed by photosystem II (PSII), a huge, multisubunit membrane-protein complex located in the thylakoid membranes of organisms ranging from cyanobacteria to higher plants. The structure of PSII has been analyzed at 1.9-Å resolution by X-ray crystallography, revealing a clear picture of the Mn4CaO5 cluster, the catalytic center for water oxidation. This article provides an overview of the overall structure of PSII followed by detailed descriptions of the specific structure of the Mn4CaO5 cluster and its surrounding protein environment. Based on the geometric organization of the Mn4CaO5 cluster revealed by the crystallographic analysis, in combination with the results of a vast number of experimental studies involving spectroscopic and other techniques as well as various theoretical studies, the article also discusses possible mechanisms for water splitting that are currently under consideration.
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Affiliation(s)
- Jian-Ren Shen
- Photosynthesis Research Center, Graduate School of Natural Science and Technology, Okayama University, Okayama 700-8530, Japan;
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Shoji M, Isobe H, Yamanaka S, Umena Y, Kawakami K, Kamiya N, Shen JR, Nakajima T, Yamaguchi K. Theoretical modelling of biomolecular systems I. Large-scale QM/MM calculations of hydrogen-bonding networks of the oxygen evolving complex of photosystem II. Mol Phys 2014. [DOI: 10.1080/00268976.2014.960021] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
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Reprint of PSII manganese cluster: protonation of W2, O5, O4 and His337 in the S1 state explored by combined quantum chemical and electrostatic energy computations. BIOCHIMICA ET BIOPHYSICA ACTA-BIOENERGETICS 2014; 1837:1389-94. [PMID: 25065862 DOI: 10.1016/j.bbabio.2014.07.008] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/26/2013] [Revised: 02/17/2014] [Accepted: 03/29/2014] [Indexed: 11/22/2022]
Abstract
Photosystem II (PSII) is a membrane-bound protein complex that oxidizes water to produce energized protons, which are used to built up a proton gradient across the thylakoidal membrane in the leafs of plants. This light-driven reaction is catalyzed by withdrawing electrons from the Mn₄CaO₅-cluster (Mn-cluster) in four discrete oxidation steps [S₁-(S₄/S₀)] characterized in the Kok-cycle. In order to understand in detail the proton release events and the subsequent translocation of such energized protons, the protonation pattern of the Mn-cluster need to be elucidated. The new high-resolution PSII crystal structure from Umena, Kawakami, Shen, and Kamiya is an excellent basis to make progress in solving this problem. Following our previous work on oxidation and protonation states of the Mn-cluster, in this work, quantum chemical/electrostatic calculations were performed in order to estimate the pKa of different protons of relevant groups and atoms of the Mn-cluster such as W2, O4, O5 and His337. In broad agreement with previous experimental and theoretical work, our data suggest that W2 and His337 are likely to be in hydroxyl and neutral form, respectively, O5 and O4 to be unprotonated. This article is part of a special issue entitled: photosynthesis research for sustainability: keys to produce clean energy.
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Robertazzi A, Galstyan A, Knapp EW. PSII manganese cluster: protonation of W2, O5, O4 and His337 in the S1 state explored by combined quantum chemical and electrostatic energy computations. BIOCHIMICA ET BIOPHYSICA ACTA-BIOENERGETICS 2014; 1837:1316-21. [PMID: 24721390 DOI: 10.1016/j.bbabio.2014.03.018] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/26/2013] [Revised: 02/17/2014] [Accepted: 03/29/2014] [Indexed: 10/25/2022]
Abstract
Photosystem II (PSII) is a membrane-bound protein complex that oxidizes water to produce energized protons, which are used to built up a proton gradient across the thylakoidal membrane in the leafs of plants. This light-driven reaction is catalyzed by withdrawing electrons from the Mn₄CaO₅-cluster (Mn-cluster) in four discrete oxidation steps [S₁-(S₄/S₀)] characterized in the Kok-cycle. In order to understand in detail the proton release events and the subsequent translocation of such energized protons, the protonation pattern of the Mn-cluster need to be elucidated. The new high-resolution PSII crystal structure from Umena, Kawakami, Shen, and Kamiya is an excellent basis to make progress in solving this problem. Following our previous work on oxidation and protonation states of the Mn-cluster, in this work, quantum chemical/electrostatic calculations were performed in order to estimate the pKa of different protons of relevant groups and atoms of the Mn-cluster such as W2, O4, O5 and His337. In broad agreement with previous experimental and theoretical work, our data suggest that W2 and His337 are likely to be in hydroxyl and neutral form, respectively, O5 and O4 to be unprotonated. This article is part of a Special Issue entitled: Photosynthesis Research for Sustainability: Keys to Produce Clean Energy.
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Affiliation(s)
- Arturo Robertazzi
- Department of Biology, Chemistry and Pharmacy, Institute of Chemistry and Biochemistry, Freie Universität Berlin, Fabeckstr. 36a, D-14195 Berlin, Germany
| | - Artur Galstyan
- Department of Biology, Chemistry and Pharmacy, Institute of Chemistry and Biochemistry, Freie Universität Berlin, Fabeckstr. 36a, D-14195 Berlin, Germany
| | - Ernst Walter Knapp
- Department of Biology, Chemistry and Pharmacy, Institute of Chemistry and Biochemistry, Freie Universität Berlin, Fabeckstr. 36a, D-14195 Berlin, Germany.
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Blomberg MRA, Borowski T, Himo F, Liao RZ, Siegbahn PEM. Quantum chemical studies of mechanisms for metalloenzymes. Chem Rev 2014; 114:3601-58. [PMID: 24410477 DOI: 10.1021/cr400388t] [Citation(s) in RCA: 436] [Impact Index Per Article: 43.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/08/2023]
Affiliation(s)
- Margareta R A Blomberg
- Department of Organic Chemistry, Arrhenius Laboratory, Stockholm University , SE-106 91 Stockholm, Sweden
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Terrett R, Petrie S, Pace RJ, Stranger R. What does the Sr-substituted 2.1 Å resolution crystal structure of photosystem II reveal about the water oxidation mechanism? Chem Commun (Camb) 2014; 50:3187-90. [DOI: 10.1039/c3cc49324e] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
The structure of the water oxidising complex in the Sr-substituted X-ray crystal structure of photosystem II and its differences relative to the Ca-containing system, have been rationalized by a density functional study.
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Affiliation(s)
- Richard Terrett
- Research School of Chemistry
- College of Physical Sciences and Mathematics
- The Australian National University
- , Australia
| | - Simon Petrie
- Research School of Chemistry
- College of Physical Sciences and Mathematics
- The Australian National University
- , Australia
| | - Ron J. Pace
- Research School of Chemistry
- College of Physical Sciences and Mathematics
- The Australian National University
- , Australia
| | - Robert Stranger
- Research School of Chemistry
- College of Physical Sciences and Mathematics
- The Australian National University
- , Australia
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32
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Yamaguchi K, Kitagawa Y, Isobe H, Shoji M, Yamanaka S, Okumura M. Reprint of “Theory of chemical bonds in metalloenzymes XVIII. Importance of mixed-valence configurations for Mn5O5, CaMn4O5 and Ca2Mn3O5 clusters revealed by UB3LYP computations. A bio-inspired strategy for artificial photosynthesis”. Polyhedron 2013. [DOI: 10.1016/j.poly.2013.08.003] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
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Yamaguchi K, Yamanaka S, Shoji M, Isobe H, Kitagawa Y, Kawakami T, Yamada S, Okumura M. Theory of chemical bonds in metalloenzymes XIX: labile manganese oxygen bonds of the CaMn4O5cluster in oxygen evolving complex of photosystem II. Mol Phys 2013. [DOI: 10.1080/00268976.2013.842009] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
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Retegan M, Neese F, Pantazis DA. Convergence of QM/MM and Cluster Models for the Spectroscopic Properties of the Oxygen-Evolving Complex in Photosystem II. J Chem Theory Comput 2013; 9:3832-42. [PMID: 26584129 DOI: 10.1021/ct400477j] [Citation(s) in RCA: 48] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
The latest crystal structure of photosystem II at 1.9 Å resolution, which resolves the topology of the Mn4CaO5 oxygen evolving complex (OEC) at atomistic detail, enables a better correlation between structural features and spectroscopic properties than ever before. Building on the refined crystallographic model of the OEC and the protein, we present combined quantum mechanical/molecular mechanical (QM/MM) studies of the spectroscopic properties of the natural catalyst embedded in the protein matrix. Focusing on the S2 state of the catalytic cycle, we examine the convergence of not only structural parameters but also of the intracluster magnetic interactions in terms of exchange coupling constants and of experimentally relevant (55)Mn, (17)O, and (14)N hyperfine coupling constants with respect to QM/MM partitioning using five QM regions of increasing size. This enables us to assess the performance of the method and to probe second sphere effects by identifying amino acid residues that principally affect the spectroscopic properties of the OEC. Comparison between QM-only and QM/MM treatments reveals that whereas QM/MM models converge quickly to stable values, the QM cluster models need to incorporate significantly larger parts of the second coordination sphere and surrounding water molecules to achieve convergence for certain properties. This is mainly due to the sensitivity of the QM-only models to fluctuations in the hydrogen bonding network and ligand acidity. Additionally, a hydrogen bond that is typically omitted in QM-only treatments is shown to determine the hyperfine coupling tensor of the unique Mn(III) ion by regulating the rotation plane of the ligated D1-His332 imidazole ring, the only N-donor ligand of the OEC.
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Affiliation(s)
- Marius Retegan
- Max Planck Institute for Chemical Energy Conversion, Stiftstr. 34-38, 45470 Mülheim an der Ruhr, Germany
| | - Frank Neese
- Max Planck Institute for Chemical Energy Conversion, Stiftstr. 34-38, 45470 Mülheim an der Ruhr, Germany
| | - Dimitrios A Pantazis
- Max Planck Institute for Chemical Energy Conversion, Stiftstr. 34-38, 45470 Mülheim an der Ruhr, Germany
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35
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Yamaguchi K, Kitagawa Y, Isobe H, Shoji M, Yamanaka S, Okumura M. Theory of chemical bonds in metalloenzymes XVIII. Importance of mixed-valence configurations for Mn5O5, CaMn4O5 and Ca2Mn3O5 clusters revealed by UB3LYP computations. A bio-inspired strategy for artificial photosynthesis. Polyhedron 2013. [DOI: 10.1016/j.poly.2013.04.019] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
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36
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Vinyard DJ, Ananyev GM, Charles Dismukes G. Photosystem II: The Reaction Center of Oxygenic Photosynthesis. Annu Rev Biochem 2013; 82:577-606. [DOI: 10.1146/annurev-biochem-070511-100425] [Citation(s) in RCA: 279] [Impact Index Per Article: 25.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Affiliation(s)
- David J. Vinyard
- Department of Chemistry and Chemical Biology and the Waksman Institute of Microbiology, Rutgers, The State University of New Jersey, Piscataway, New Jersey 08854; ,
- Department of Chemistry, Princeton University, Princeton, New Jersey 08540;
| | - Gennady M. Ananyev
- Department of Chemistry and Chemical Biology and the Waksman Institute of Microbiology, Rutgers, The State University of New Jersey, Piscataway, New Jersey 08854; ,
| | - G. Charles Dismukes
- Department of Chemistry and Chemical Biology and the Waksman Institute of Microbiology, Rutgers, The State University of New Jersey, Piscataway, New Jersey 08854; ,
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Sigfridsson KGV, Chernev P, Leidel N, Popović-Bijelić A, Gräslund A, Haumann M. Rapid X-ray photoreduction of dimetal-oxygen cofactors in ribonucleotide reductase. J Biol Chem 2013; 288:9648-9661. [PMID: 23400774 DOI: 10.1074/jbc.m112.438796] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Prototypic dinuclear metal cofactors with varying metallation constitute a class of O2-activating catalysts in numerous enzymes such as ribonucleotide reductase. Reliable structures are required to unravel the reaction mechanisms. However, protein crystallography data may be compromised by x-ray photoreduction (XRP). We studied XPR of Fe(III)Fe(III) and Mn(III)Fe(III) sites in the R2 subunit of Chlamydia trachomatis ribonucleotide reductase using x-ray absorption spectroscopy. Rapid and biphasic x-ray photoreduction kinetics at 20 and 80 K for both cofactor types suggested sequential formation of (III,II) and (II,II) species and similar redox potentials of iron and manganese sites. Comparing with typical x-ray doses in crystallography implies that (II,II) states are reached in <1 s in such studies. First-sphere metal coordination and metal-metal distances differed after chemical reduction at room temperature and after XPR at cryogenic temperatures, as corroborated by model structures from density functional theory calculations. The inter-metal distances in the XPR-induced (II,II) states, however, are similar to R2 crystal structures. Therefore, crystal data of initially oxidized R2-type proteins mostly contain photoreduced (II,II) cofactors, which deviate from the native structures functional in O2 activation, explaining observed variable metal ligation motifs. This situation may be remedied by novel femtosecond free electron-laser protein crystallography techniques.
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Affiliation(s)
| | - Petko Chernev
- Free University Berlin, Institute of Experimental Physics, 14195 Berlin, Germany
| | - Nils Leidel
- Free University Berlin, Institute of Experimental Physics, 14195 Berlin, Germany
| | - Ana Popović-Bijelić
- Department of Biochemistry and Biophysics, Stockholm University, 10691 Stockholm, Sweden
| | - Astrid Gräslund
- Department of Biochemistry and Biophysics, Stockholm University, 10691 Stockholm, Sweden
| | - Michael Haumann
- Free University Berlin, Institute of Experimental Physics, 14195 Berlin, Germany.
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38
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Shoji M, Isobe H, Yamanaka S, Umena Y, Kawakami K, Kamiya N, Shen JR, Yamaguchi K. Theoretical insight in to hydrogen-bonding networks and proton wire for the CaMn4O5 cluster of photosystem II. Elongation of Mn–Mn distances with hydrogen bonds. Catal Sci Technol 2013. [DOI: 10.1039/c3cy00051f] [Citation(s) in RCA: 45] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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39
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Gatt P, Petrie S, Stranger R, Pace RJ. Rationalizing the 1.9 Å Crystal Structure of Photosystem II-A Remarkable Jahn-Teller Balancing Act Induced by a Single Proton Transfer. Angew Chem Int Ed Engl 2012. [DOI: 10.1002/ange.201206316] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
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40
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Gatt P, Petrie S, Stranger R, Pace RJ. Rationalizing the 1.9 Å crystal structure of photosystem II--A remarkable Jahn-Teller balancing act induced by a single proton transfer. Angew Chem Int Ed Engl 2012; 51:12025-8. [PMID: 23108989 DOI: 10.1002/anie.201206316] [Citation(s) in RCA: 61] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/07/2012] [Indexed: 01/01/2023]
Affiliation(s)
- Phillip Gatt
- Research School of Chemistry, Australian National University, Canberra ACT 0200, Australia
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41
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Siegbahn PEM. Water oxidation mechanism in photosystem II, including oxidations, proton release pathways, O-O bond formation and O2 release. BIOCHIMICA ET BIOPHYSICA ACTA-BIOENERGETICS 2012; 1827:1003-19. [PMID: 23103385 DOI: 10.1016/j.bbabio.2012.10.006] [Citation(s) in RCA: 286] [Impact Index Per Article: 23.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/18/2012] [Revised: 10/15/2012] [Accepted: 10/18/2012] [Indexed: 11/17/2022]
Abstract
The present status of DFT studies on water oxidation in photosystem II is described. It is argued that a full understanding of all steps is close. In each S-transition, the manganese that is oxidized and the proton released are strongly implicated, and structures of all intermediates have been determined. For the S2-state, recent important experimental findings support key elements of the structure and the mechanism. In this mechanism, the O-O bond is formed between an oxyl radical in the center of the cluster and an Mn-bridging μ-oxo ligand, which was suggested already in 2006. The DFT structure of the oxygen evolving complex, suggested in 2008, is very similar to the recent high-resolution X-ray structure. Some new aspects of the interaction between P680 and the OEC are suggested. This article is part of a Special Issue entitled: Metals in Bioenergetics and Biomimetics Systems.
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Isobe H, Shoji M, Yamanaka S, Umena Y, Kawakami K, Kamiya N, Shen JR, Yamaguchi K. Theoretical illumination of water-inserted structures of the CaMn4O5 cluster in the S2 and S3 states of oxygen-evolving complex of photosystem II: full geometry optimizations by B3LYP hybrid density functional. Dalton Trans 2012; 41:13727-40. [DOI: 10.1039/c2dt31420g] [Citation(s) in RCA: 162] [Impact Index Per Article: 13.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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