Three-dimensional structure of the plant photosystem II reaction centre at 8 Å resolution

Rhee, Kyong−Hi; Morris, Edward; Barber, James; Kühlbrandt, Werner

doi:10.1038/24421

Cited by 340 publications

(316 citation statements)

References 27 publications

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“…This observation is consistent with the estimated 10 Å center to center distance between the metal centers of these chlorophylls from electron and X-ray diffraction studies of PSII crystals (17,18,73) as opposed to the 7.6 Å found in bacterial reaction centers (3)(4)(5).…”

Section: Location Of 3 P As a Function Of Temperaturesupporting

confidence: 88%

“…(3) In the bacterial reaction centers the electrochromic shift of the accessory chlorophyll (B A , B B , or both) accompanying the oxidation of the primary donor is to the blue (96,97). Because of the similar orientation of the reaction center chlorophylls to those of the bacterial reaction centers (3,5,8,9,10,17,18,98), we expect a similar blue shift in PSII if the cation were localized on P A + . If the cation were localized on B A , then because of the closeness of ring I of P B to B A + , there would likely be an electrochromic shift of P B which would be insensitive to the D1-198 mutations.…”

Section: Location Of 3 P As a Function Of Temperaturementioning

confidence: 97%

“…Homology modeling and the C 2 symmetry of the reaction center point to the D2-His197 coordinated P B chlorophyll as being the most likely optical probe for this tyrosine (10,17,73). 3 P-1 P Difference Spectra.…”

Section: Site-directed Mutationsmentioning

confidence: 99%

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Site-Directed Mutations at D1-His198 and D2-His197 of Photosystem II in Synechocystis PCC 6803: Sites of Primary Charge Separation and Cation and Triplet Stabilization

et al. 2001

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Site-directed mutations were introduced to replace D1-His198 and D2-His197 of the D1 and D2 polypeptides, respectively, of the photosystem II (PSII) reaction center of Synechocystis PCC 6803. These residues coordinate chlorophylls P A and P B which are homologous to the special pair Bchlorophylls of the bacterial reaction centers that are coordinated respectively by histidines L-173 and M-200 (202). P A and P B together serve as the primary electron donor, P, in purple bacterial reaction centers. In PS II, the site-directed mutations at D1 His198 affect the P + -P-absorbance difference spectrum. The bleaching maximum in the Soret region (in WT at 433 nm) is blue-shifted by as much as 3 nm. In the D1 His198Gln mutant, a similar displacement to the blue is observed for the bleaching maximum in the Q y region (672.5 nm in WT at 80 K), whereas features attributed to a band shift centered at 681 nm are not altered. In the Y Z •-Y Z -difference spectrum, the band shift of a reaction center chlorophyll centered in WT at 433-434 nm is shifted by 2-3 nm to the blue in the D1-His198Gln mutant. The D1-His198Gln mutation has little effect on the optical difference spectrum, 3 P-1 P, of the reaction center triplet formed by P + Pheo -charge recombination (bleaching at 681-684 nm), measured at 5-80 K, but becomes visible as a pronounced shoulder at 669 nm at temperatures g150 K. Measurements of the kinetics of oxidized donor-Q A -charge recombination and of the reduction of P + by redox active tyrosine, Y Z , indicate that the reduction potential of the redox couple P + /P can be appreciably modulated both positively and negatively by ligand replacement at D1-198 but somewhat less so at D2-197. On the basis of these observations and others in the literature, we propose that the monomeric accessory chlorophyll, B A , is a long-wavelength trap located at 684 nm at 5 K. B A * initiates primary charge separation at low temperature, a function that is increasingly shared with P A * in an activated process as the temperature rises. Charge separation from B A * would be potentially very fast and form P A + B A -and/or B A + Pheo -as observed in bacterial reaction centers upon direct excitation of B A ) Proc. Natl. Acad Sci. 96, 2054-2059. The cation, generated upon primary charge separation in PSII, is stabilized at all temperatures primarily on P A , the absorbance spectrum of which is displaced to the blue by the mutations. In WT, the cation is proposed to be shared to a minor extent (∼20%) with P B , the contribution of which can be modulated up or down by mutation. The band shift at 681 nm, observed in the P + -P difference spectrum, is attributed to an electrochromic effect of P A + on neighboring B A . Because of its low-energy singlet and therefore triplet state, the reaction center triplet state is stabilized on B A at e80 K but can be shared with P A at >80 K in a thermally activated process.

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Section: Location Of 3 P As a Function Of Temperaturesupporting

confidence: 88%

Section: Location Of 3 P As a Function Of Temperaturementioning

confidence: 97%

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Site-Directed Mutations at D1-His198 and D2-His197 of Photosystem II in Synechocystis PCC 6803: Sites of Primary Charge Separation and Cation and Triplet Stabilization

et al. 2001

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“…These studies relied on mild detergent solubilization procedures and refined electron microscopy analysis, including single particle averaging (Boekema et al, 1999), cryoelectron microscopy (Nield et al, 2000), and two-dimensional crystal electron diffraction (Rhee et al, 1998;Barber and Kuhlbrandt, 1999;Hankamer et al, 1999). Various PSII forms were observed, ranging from a large protein complex retaining its peripheral antenna complement to subcore particles.…”

Section: Discussionmentioning

confidence: 99%

The Chloroplast Gene ycf9 Encodes a Photosystem II (PSII) Core Subunit, PsbZ, That Participates in PSII Supramolecular Architecture

Świątek¹,

Kuras²,

Sokilenko³

et al. 2001

The Plant Cell

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We have characterized the biochemical nature and the function of PsbZ, the protein product of a ubiquitous open reading frame, which is known as ycf9 in Chlamydomonas and ORF 62 in tobacco, that is present in chloroplast and cyanobacterial genomes. After raising specific antibodies to PsbZ from Chlamydomonas and tobacco, we demonstrated that it is a bona fide photosystem II (PSII) subunit. PsbZ copurifies with PSII cores in Chlamydomonas as well as in tobacco. Accordingly, PSII mutants from Chlamydomonas and tobacco are deficient in PsbZ. Using psbZ -targeted gene inactivation in tobacco and Chlamydomonas, we show that this protein controls the interaction of PSII cores with the light-harvesting antenna; in particular, PSII-LHCII supercomplexes no longer could be isolated from PsbZ-deficient tobacco plants. The content of the minor chlorophyll binding protein CP26, and to a lesser extent that of CP29, also was altered substantially under most growth conditions in the tobacco mutant and in Chlamydomonas mutant cells grown under photoautotrophic conditions. These PsbZ-dependent changes in the supramolecular organization of the PSII cores with their peripheral antennas cause two distinct phenotypes in tobacco and are accompanied by considerable modifications in (1) the pattern of protein phosphorylation within PSII units, (2) the deepoxidation of xanthophylls, and (3) the kinetics and amplitude of nonphotochemical quenching. The role of PsbZ in excitation energy dissipation within PSII is discussed in light of its proximity to CP43, in agreement with the most recent structural data on PSII. INTRODUCTIONWith the completion of an ever-increasing number of chloroplast genome sequences (Quigley and Weil, 1985; Bookjans et al., 1986;Ohyama et al., 1986;Shinozaki et al., 1986; Hiratsuka et al., 1989; Evrard et al., 1990; Hallick et al., 1993; Wakasugi et al., 1994 Wakasugi et al., , 1997Kowallik et al., 1995;Maier et al., 1995;Reith and Munholland, 1995; Douglas and Penny, 1999;Sato et al., 1999; Turmel et al., 1999;Hupfer et al., 2000;Lemieux et al., 2000), the functions of most of the major open reading frames of chloroplast DNA have now been studied. The ability to perform reverse genetics with tobacco and Chlamydomonas chloroplasts has contributed greatly to this process. However, this strategy, which consists mainly of the phenotypic characterization of mutants inactivated for the gene under study, can be unsuccessful in two cases: (1) when the gene product is required for cell viability, in which case homoplasmic transformation cannot be obtained, and (2) when homoplasmic transformants do not display any clear-cut mutant phenotype under laboratory conditions. In both cases, this may preclude a reliable functional characterization of the gene and its product.ycf9 , which is predicted to encode a 6.5-kD protein with two putative membrane-spanning segments, is an interesting case because attempts to inactivate the gene have yielded widely different results ranging from potential lethality to 1 These authors cont...

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“…It had been shown by electron microscopy (EM) that the PSIIRC core complex of plants and cyanobacteria is dimeric (reviewed in Hankamer et al 1997). In fact, our early EM studies employing both electron crystallography (Rhee et al 1997(Rhee et al , 1998Hankamer et al 1999Hankamer et al , 2001) and single particle analyses (Nield et al 2000a(Nield et al ,b, 2002 had also revealed the relative positions of the D1, D2, CP43 and CP47 proteins within each monomer of the dimeric PSII RC core complex isolated from higher plants (spinach) and suggested how their transmembrane helices were arranged (Barber 2002). The best resolution obtained was 8 Å and thus densities could be tentatively assigned to Chls bound within the CP47 protein as well as those that were contained within the D1/D2 heterodimer (Rhee et al 1998).…”

Section: The Structure Of Psii and Its Oecmentioning

confidence: 99%

Photosynthetic generation of oxygen

Barber

2008

Phil. Trans. R. Soc. B

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The oxygen in the atmosphere is derived from light-driven oxidation of water at a catalytic centre contained within a multi-subunit enzyme known as photosystem II (PSII). PSII is located in the photosynthetic membranes of plants, algae and cyanobacteria and its oxygen-evolving centre (OEC) consists of four manganese ions and a calcium ion surrounded by a highly conserved protein environment. Recently, the structure of PSII was elucidated by X-ray crystallography thus revealing details of the molecular architecture of the OEC. This structural information, coupled with an extensive knowledge base derived from a wide range of biophysical, biochemical and molecular biological studies, has provided a framework for understanding the chemistry of photosynthetic oxygen generation as well as opening up debate about its evolutionary origin.

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Three-dimensional structure of the plant photosystem II reaction centre at 8 Å resolution

Cited by 340 publications

References 27 publications

Site-Directed Mutations at D1-His198 and D2-His197 of Photosystem II in Synechocystis PCC 6803: Sites of Primary Charge Separation and Cation and Triplet Stabilization

Site-Directed Mutations at D1-His198 and D2-His197 of Photosystem II in Synechocystis PCC 6803: Sites of Primary Charge Separation and Cation and Triplet Stabilization

The Chloroplast Gene ycf9 Encodes a Photosystem II (PSII) Core Subunit, PsbZ, That Participates in PSII Supramolecular Architecture

Photosynthetic generation of oxygen

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