Photosystem II: The machinery of photosynthetic water splitting

Ренгер, Г.; Renger, Thomas

doi:10.1007/s11120-008-9345-7

Cited by 284 publications

(248 citation statements)

References 200 publications

(261 reference statements)

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“…This may indicate that PsbR plays auxiliary functions in facilitating the interaction between PsbP and PsbE, as suggested by the recent observation that PsbP can associate with PSII without PsbR. 3 We then analyzed whether H144A and H144A/D165V mutations affected the cross-linking between PsbP and PsbE. The amount of the PsbP-PsbE cross-linked product was significantly decreased in the H144A-reconstituted PSII complex compared with the WT-reconstituted PSII complex, and was restored in the H144A/D165V-reconstituted PSII (Fig.…”

Section: D165v Mutation Of the H144a Mutant Psbp Protein Restored Thementioning

confidence: 90%

The Conserved His-144 in the PsbP Protein Is Important for the Interaction between the PsbP N-terminus and the Cyt b559 Subunit of Photosystem II

Ido

Kakiuchi

Uno

et al. 2012

Journal of Biological Chemistry

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Background:PsbP is an extrinsic subunit of photosystem II in green plants. Results: H144A mutation in PsbP alters the chloride requirement and affects the interaction between its N terminus and the PsbE component of photosystem II. Conclusion:The N-and C-terminal domains of PsbP cooperate to support PSII activity. Significance: This provides important information about the binding characteristics of PsbP in green plant PSII.The PsbP protein regulates the binding properties of Ca 2؉ and Cl ؊ , and stabilizes the Mn cluster of photosystem II (PSII); however, the binding site and topology in PSII have yet to be clarified. Here we report that the structure around His-144 and Asp-165 in PsbP, which is suggested to be a metal binding site, has a crucial role for the functional interaction between PsbP and PSII. The mutated PsbP-H144A protein exhibits reduced ability to retain Cl ؊ anions in PSII, whereas the D165V mutation does not affect PsbP function. Interestingly, H144A/D165V double mutation suppresses the effect of H144A mutation, suggesting that these residues have a role other than metal binding. FTIR difference spectroscopy suggests that H144A/D165V restores proper interaction with PSII and induces the conformational change around the Mn cluster during the S 1 /S 2 transition. Cross-linking experiments show that the H144A mutation affects the direct interaction between PsbP and the Cyt b 559 ␣ subunit of PSII (the PsbE protein). However, this interaction is restored in the H144A/D165V mutant. In the PsbP structure, His-144 and Asp-165 form a salt bridge. H144A mutation is likely to disrupt this bridge and liberate Asp-165, inhibiting the proper PsbP-PSII interaction. Finally, mass spectrometric analysis has identified the cross-linked sites of PsbP and PsbE as Ala-1 and Glu-57, respectively. Therefore His-144, in the C-terminal domain of PsbP, plays a crucial role in maintaining proper N terminus interaction. These data provide important information about the binding characteristics of PsbP in green plant PSII.Photosystem II (PSII) 2 consists of both membrane-intrinsic and membrane-extrinsic subunits, and functions as a water/ plastoquinone oxidoreductase (for reviews, Refs. 1-4). On the thylakoid lumenal side of PSII, a metal cluster of four Mn ions, one Ca 2ϩ ion, and five oxo ligands (the Mn cluster) catalyzes the oxygen-evolving reaction. Additionally, two Cl Ϫ ions are bound near to the Mn cluster (5). The membrane-intrinsic subunits of PSII are involved in pigment and/or cofactor binding for photochemical reactions, while the membrane-extrinsic subunits surround the catalytic Mn cluster and play crucial roles in stabilizing the Mn cluster and retaining the PSII cofactor ions (6 -8).X-ray structural analysis of the cyanobacterial PSII complex at atomic resolution has revealed the location of subunits, pigments, and cofactors, including the exact organization of the subunits within PSII (5, 9 -11). However, the crystallographic information gained from the study of cyanobacterial PSII cannot necessarily be...

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Section: D165v Mutation Of the H144a Mutant Psbp Protein Restored Thementioning

confidence: 90%

The Conserved His-144 in the PsbP Protein Is Important for the Interaction between the PsbP N-terminus and the Cyt b559 Subunit of Photosystem II

Ido

Kakiuchi

Uno

et al. 2012

Journal of Biological Chemistry

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“…on the ET kinetics and accompanying protonation reactions (reviewed in Refs. [15][16][17][18][19], preferentially on BRCs for which high resolution (Յ2 Å) crystal data are available (20 -23). Crystal structures of PSII so far were reported only at a lower resolution of Ն2.9 Å (7, 8) (a structure at higher resolution may become available in the future) (24).…”

mentioning

confidence: 99%

“…Crystal structures of PSII so far were reported only at a lower resolution of Ն2.9 Å (7, 8) (a structure at higher resolution may become available in the future) (24). For both PSII and BRCs, in particular the function of the non-heme iron and of its carboxyl ligand in the ET reactions has remained enigmatic (15)(16)(17)(18)(19).…”

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confidence: 99%

Carboxylate Shifts Steer Interquinone Electron Transfer in Photosynthesis

Chernev

Zaharieva

Dau

et al. 2011

Journal of Biological Chemistry

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Understanding the mechanisms of electron transfer (ET) in photosynthetic reaction centers (RCs) may inspire novel catalysts for sunlight-driven fuel production. The electron exit pathway of type II RCs comprises two quinone molecules working in series and in between a non-heme iron atom with a carboxyl ligand (bicarbonate in photosystem II (PSII), glutamate in bacterial RCs). For decades, the functional role of the iron has remained enigmatic. We tracked the iron site using microsecond-resolution x-ray absorption spectroscopy after laser-flash excitation of PSII. After formation of the reduced primary quinone, Q A ؊ , the x-ray spectral changes revealed a transition (t1 ⁄ 2 ≈ 150 s) from a bidentate to a monodentate coordination of the bicarbonate at the Fe(II) (carboxylate shift), which reverted concomitantly with the slower ET to the secondary quinone Q B . A redox change of the iron during the ET was excluded. Density-functional theory calculations corroborated the carboxylate shift both in PSII and bacterial RCs and disclosed underlying changes in electronic configuration. We propose that the iron-carboxyl complex facilitates the first interquinone ET by optimizing charge distribution and hydrogen bonding within the Q A FeQ B triad for high yield Q B reduction. Formation of a specific priming intermediate by nuclear rearrangements, setting the stage for subsequent ET, may be a common motif in reactions of biological redox cofactors.

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“…These two are not in disagreement with respect to the nature of the primary charge separation, but they differ in the value of rate constants and the question of "transfer to the trap limited" or "trap-limited reaction" (5). In this report, we used the term the special pair instead of the primary electron donor to avoid confusion on the identification of the primary electron donor in PS II.…”

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confidence: 99%

Redox potential of pheophytin a in photosystem II of two cyanobacteria having the different special pair chlorophylls

Allakhverdiev

Tomo

Shimada

et al. 2010

Proc. Natl. Acad. Sci. U.S.A.

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Water oxidation by photosystem (PS) II in oxygenic photosynthetic organisms is a major source of energy on the earth, leading to the production of a stable reductant. Mechanisms generating a high oxidation potential for water oxidation have been a major focus of photosynthesis research. This potential has not been estimated directly but has been measured by the redox potential of the primary electron acceptor, pheophytin (Phe) a. However, the reported values for Phe a are still controversial. Here, we measured the redox potential of Phe a under physiological conditions (pH 7.0; 25°C) in two cyanobacteria with different special pair chlorophylls (Chls): Synechocystis sp. PCC 6803, whose special pair for PS II consists of Chl a, and Acaryochloris marina MBIC 11017, whose special pair for PS II consists of Chl d. We obtained redox potentials of −536 ± 8 mV for Synechocystis sp. PCC 6803 and −478 ± 24 mV for A. marina on PS II complexes in the presence of 1.0 M betaine. The difference in the redox potential of Phe a between the two species closely corresponded with the difference in the light energy absorbed by Chl a versus Chl d. We estimated the potentials of the special pair of PS II to be 1.20 V and 1.18 V for Synechocystis sp. PCC 6803 (P680) and A. marina (P713), respectively. This clearly indicates conservation in the properties of water-oxidation systems in oxygenic photosynthetic organisms, irrespective of the special-pair chlorophylls.hotosynthesis mediates the conversion of solar light energy to chemical-bond energy through multistep reactions. Two photosystems (PSs) are present in oxygenic photosynthetic organisms, and these two PSs function cooperatively to capture light energy and drive electron flow. PS II supplies an energy source (i.e., an electron) by water oxidation, and PS I supplies a highly reduced compound, NADPH, to reduce CO 2 to carbohydrates.Reaction processes in the electron transfer system in photosynthesis are governed by two major factors: the relative geometry and the redox potentials of the electron transfer components. The molecular environment supplied by the amino acid matrix of the components will give a supplemental effect(s). Crystal structures of PS II complexes at atomic resolution have been reported from several laboratories (1-4). Thus, with the exception of some inconsistencies in the water-oxidation reaction system, an essential part of the primary charge separation machinery has been characterized (5). The electron transfer mechanisms, in contrast,have not yet been clarified in most cases.Pheophytin (Phe) a is the primary electron acceptor in PS II (6-8), although the primary electron donor of PS II is still controversial [P680 or accessory chlorophyll (Chl) a] (9, 10). These two are not in disagreement with respect to the nature of the primary charge separation, but they differ in the value of rate constants and the question of "transfer to the trap limited" or "trap-limited reaction" (5). In this report, we used the term the special pair instead of the primary electron...

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Photosystem II: The machinery of photosynthetic water splitting

Cited by 284 publications

References 200 publications

The Conserved His-144 in the PsbP Protein Is Important for the Interaction between the PsbP N-terminus and the Cyt b559 Subunit of Photosystem II

The Conserved His-144 in the PsbP Protein Is Important for the Interaction between the PsbP N-terminus and the Cyt b559 Subunit of Photosystem II

Carboxylate Shifts Steer Interquinone Electron Transfer in Photosynthesis

Redox potential of pheophytin a in photosystem II of two cyanobacteria having the different special pair chlorophylls

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