Structural and dynamic insights into Mn4Ca cluster-depleted Photosystem II

2021 ◽  
Author(s):  
Daniele Narzi ◽  
Leonardo Guidoni
Keyword(s):  
Photosystem Ii ◽  
Molecular Oxygen ◽  
Oxygenic Photosynthesis ◽  
Water Molecules ◽  
Sun Light

In the first steps of natural oxygenic photosynthesis, Sun light is used to oxidize water molecules into protons, electrons and molecular oxygen. This reaction takes place on the Mn$_4$Ca cluster...

scholarly journals Rigidly hydrogen-bonded water molecules facilitate proton transfer in photosystem II

2020 ◽  
Vol 22 (28) ◽  
pp. 15831-15841
Author(s):  
Naoki Sakashita ◽  
Hiroshi Ishikita ◽  
Keisuke Saito
Keyword(s):  
Photosystem Ii ◽  
Proton Transfer ◽  
Water Molecules ◽  
Hydrogen Bonded

In the channel of photosystem II, rigidly hydrogen-bonded water molecules facilitate the Grotthuss-like proton transfer, whereas flexible water molecules prevent proton transfer in the channel of aquaporin.

scholarly journals Untangling the sequence of events during the S2→ S3transition in photosystem II and implications for the water oxidation mechanism

2020 ◽  
Vol 117 (23) ◽  
pp. 12624-12635 ◽  
Author(s):  
Mohamed Ibrahim ◽  
Thomas Fransson ◽  
Ruchira Chatterjee ◽  
Mun Hon Cheah ◽  
Rana Hussein ◽  
...  
Keyword(s):  
Photosystem Ii ◽  
Water Oxidation ◽  
Donor Site ◽  
Oxidation Mechanism ◽  
Oxygenic Photosynthesis ◽  
Acceptor Site ◽  
Oxygen Evolving Complex ◽  
Ps Ii ◽  
Sequence Of Events ◽  
Large Channel

In oxygenic photosynthesis, light-driven oxidation of water to molecular oxygen is carried out by the oxygen-evolving complex (OEC) in photosystem II (PS II). Recently, we reported the room-temperature structures of PS II in the four (semi)stable S-states, S1, S2, S3, and S0, showing that a water molecule is inserted during the S2→ S3transition, as a new bridging O(H)-ligand between Mn1 and Ca. To understand the sequence of events leading to the formation of this last stable intermediate state before O2formation, we recorded diffraction and Mn X-ray emission spectroscopy (XES) data at several time points during the S2→ S3transition. At the electron acceptor site, changes due to the two-electron redox chemistry at the quinones, QAand QB, are observed. At the donor site, tyrosine YZand His190 H-bonded to it move by 50 µs after the second flash, and Glu189 moves away from Ca. This is followed by Mn1 and Mn4 moving apart, and the insertion of OX(H) at the open coordination site of Mn1. This water, possibly a ligand of Ca, could be supplied via a “water wheel”-like arrangement of five waters next to the OEC that is connected by a large channel to the bulk solvent. XES spectra show that Mn oxidation (τ of ∼350 µs) during the S2→ S3transition mirrors the appearance of OXelectron density. This indicates that the oxidation state change and the insertion of water as a bridging atom between Mn1 and Ca are highly correlated.

scholarly journals Energetics of Ionized Water Molecules in the H-Bond Network near the Ca2+ and Cl– Binding Sites in Photosystem II

Biochemistry ◽  
2020 ◽  
Vol 59 (35) ◽  
pp. 3216-3224 ◽  
Author(s):  
Keisuke Saito ◽  
Manoj Mandal ◽  
Hiroshi Ishikita
Keyword(s):  
Photosystem Ii ◽  
Binding Sites ◽  
Water Molecules ◽  
Bond Network

scholarly journals Mediator-assisted water oxidation by the ruthenium “blue dimer” cis,cis-[(bpy)2(H2O)RuORu(OH2)(bpy)2]4+

2008 ◽  
Vol 105 (46) ◽  
pp. 17632-17635 ◽  
Author(s):  
Javier J. Concepcion ◽  
Jonah W. Jurss ◽  
Joseph L. Templeton ◽  
Thomas J. Meyer
Keyword(s):  
Carbon Dioxide ◽  
Electron Transfer ◽  
Renewable Energy ◽  
Photosystem Ii ◽  
Water Splitting ◽  
Water Oxidation ◽  
Oxygenic Photosynthesis ◽  
Reduced Water ◽  
Insight Into ◽  
Recent Insight

Light-driven water oxidation occurs in oxygenic photosynthesis in photosystem II and provides redox equivalents directed to photosystem I, in which carbon dioxide is reduced. Water oxidation is also essential in artificial photosynthesis and solar fuel-forming reactions, such as water splitting into hydrogen and oxygen (2 H2O + 4 hν → O2 + 2 H2) or water reduction of CO2 to methanol (2 H2O + CO2 + 6 hν → CH3OH + 3/2 O2), or hydrocarbons, which could provide clean, renewable energy. The “blue ruthenium dimer,” cis,cis-[(bpy)2(H2O)RuIIIORuIII(OH2)(bpy)2]4+, was the first well characterized molecule to catalyze water oxidation. On the basis of recent insight into the mechanism, we have devised a strategy for enhancing catalytic rates by using kinetically facile electron-transfer mediators. Rate enhancements by factors of up to ≈30 have been obtained, and preliminary electrochemical experiments have demonstrated that mediator-assisted electrocatalytic water oxidation is also attainable.

scholarly journals Impact of D1-V185 on the Water Molecules That Facilitate O2 Formation by the Catalytic Mn4CaO5 Cluster in Photosystem II

Biochemistry ◽  
2018 ◽  
Vol 57 (29) ◽  
pp. 4299-4311 ◽  
Author(s):  
Christopher J. Kim ◽  
Han Bao ◽  
Robert L. Burnap ◽  
Richard J. Debus
Keyword(s):  
Photosystem Ii ◽  
Water Molecules

Water Molecules Coupled to the Redox-Active Tyrosine YDin Photosystem II as Detected by FTIR Spectroscopy†

Biochemistry ◽  
2007 ◽  
Vol 46 (49) ◽  
pp. 14245-14249 ◽  
Author(s):  
Ryouta Takahashi ◽  
Miwa Sugiura ◽  
Takumi Noguchi
Keyword(s):  
Photosystem Ii ◽  
Ftir Spectroscopy ◽  
Water Molecules ◽  
Redox Active

Influence of Molecular Oxygen on Ortho-Para Conversion of Water Molecules

2017 ◽  
Vol 60 (3) ◽  
pp. 485-493
Author(s):  
R. R. Valiev ◽  
B. F. Minaev
Keyword(s):  
Molecular Oxygen ◽  
Water Molecules
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