Photosystem II reaction-center complex

Frank, H.A., Hansson, O. and Mathis, P. 1987. Low temperature ESR and absorption spectroscopy of the Photosystem II reaction center complex (submitted). 

Yamagishi, A. and Katoh S. 1985. Further characterization of two photosystem II reaction center complex preparations from the thermophilic cyanobacterium Synechococcus sp. Biochim. Biophys. Acta 807. 74-80. 

H Fujiwara, H Hayashi, M Tasumi, M Kanji, YKoyamaand (Ki) Satoh (1987) Structural studies on a photosystem II reaction center complex consisting ofD-1 and D-2 polypeptides and cytochrome b-559 by resonance Raman spectroscopy and high-performance liquid chromatography. Chem Lett 10 2005-2008 GE Bialek-Bylka, T Tomo, (Ki) Satoh and Y Koyama (1995) 15-cis-carotene found in the reaction center of spinach photosystem II. FEES Lett 363 137-140... 

In DR Ort and CF Yocum (eds) Oxygenic Photosynthesis. The Light Reactions, pp 213-247. Kluwer R2. M Seibert (1993) Biochemical, biophysical, and structural characterization of the isolated photosystem II reaction center complex. In J Deisenhofer and JR Norris (eds) The photosynthetic Reaction Center, vol 1 319-356 R3. WW Parson and B Ke (1982) Primary photochemical reactions. In Govindjee (ed) Photosynthesis Energy Conversion by Plants and Bacteria, Vol 1, pp 331-385. Acad Press R4. VV Klimov and AA Krasnovsky (1981) Pheophytin as the primary electron acceptor in photosystem 2 reaction centres. Photosynthetica 15 592-609... 

TA Roeiofs, M Giibert, VA Shuvaiov and AR Hoizwarth (1991) Picosecond fluorescence kinetics of the D -D2-cyt-b-559 photosystem II reaction center complex. Energy transfer and primary charge separation processes. Biochim Biophys Acta 1060 237-244... 

Y Takahashi, M-A Takahashi and Ki Satoh (1986) Identification of the site of iodide photooxidation in the photosystem II reaction center complex. FEBS Lett 208 347-351... 

Alizadeh S, Morals F, Barber ] et al. Isotopic labelling of the polypeptide subunits of the isolated photosystem II reaction-center complex of Chlamydomonas reihnhardtii suggests an ap heterodimeric structure for cytochrome b-550. J Photochem Photobiol 1999 48 148-153. 

Tomo T, Enami I, Satoh K. Orientation and nearest neighbor analysis of psbl gene product in the photosystem II reaction center complex using bifunctional cross-linkers. FEBS Lett 1993 323 15-18. 

Barbato R, Friso G, de Laureto PP et al. Light-induced d radation of D2 protdn in isolated photosystem II reaction center complex. FEBS Lett 1992a 311 33-36. 

Lorkovic ZJ, Schroeder WP, Pakrasi HB et al. Molecular characterization of PsbW, a nuclear-encoded component of the photosystem II reaction center complex in spinach. Proc Nad Acad Sci US 1995 92 8930-8934. 

Tsiotis G, Psylinakis M, Woplensinger B et al. Investigation of the structure of spinach photosystem II reaction center complex. Eur ] Biochem 1999 259(l-2) 320-4. 

SPECTRAL PROPERTIES OF ISOLATED PHOTOSYSTEM II REACTION CENTER COMPLEX AT 77K... 

Photosystem II reaction center complexes were prepared as per (11). The rates of O2 evolution were measured using a Clark-t)q>e O2 electrode with a reaction mixture that contained 25f) J,M DCBQ, 5 Xg Chl/ml and 40 mM MES or PIPES at the pH indicated. The concentration of Cl" was maintained by the addition of (CH3)4NC1 while Ca was added from stock solution s of 50... 

The Primary Charge-Separation Rate in Isolated Photosystem II Reaction Center Complex 451 M.R. Wasielewski, D.G. Johnson, Govindjee, C. Preston, M. Seibert... 

Evance, M.C.W., Rich, A.M., and Nugent, J.H.A. (2000) Evidence for the presence of a component of the Mn complex of the Photosystem II reaction center which is exposed to water in the S2 state of the water oxidation complex, FEBS Letters, All, 113-117. 

Herbicides that inhibit photosynthetic electron flow prevent reduction of plastoquinone by the photosystem II acceptor complex. The properties of the photosystem II herbicide receptor proteins have been investigated by binding and displacement studies with radiolabeled herbicides. The herbicide receptor proteins have been identified with herbicide-derived photoaffinity labels. Herbicides, similar in their mode of action to 3-(3,4-dichlorophenyl)-1,1-dimethylurea (DCMU) bind to a 34 kDa protein, whereas phenolic herbicides bind to the 43-51 kDa photosystem II reaction center proteins. At these receptor proteins, plastoquinone/herbicide interactions and plastoquinone binding sites have been studied, the latter by means of a plastoquinone-deriv-ed photoaffinity label. For the 34 kDa herbicide binding protein, whose amino acid sequence is known, herbicide and plastoquinone binding are discussed at the molecular level. 

Fig. 12.1. Relative sizes of mitochondrial and chloroplast chromosomes and location of protein structural genes. The figure was constructed from published data [5,15,17,22,26-28]. The structural genes are marked by wide sections. Black areas code for proteins. White areas are introns. 0x1, OxII and OxIII are subunits I, II and III of cytochrome c oxidase. Cyt b, cytochrome b. Fo and Fo, are subunits 6 and 9 of the proton ATPase complex. In the chloroplast chromosome the arrows indicate the transcription direction and the size of the transcripts. CF,a, CFj/8, CFjc and CFoIII are subunits a, /S, t and III of the chloroplast proton ATPase complex [30]. PSII5], PSII44, and PSII34 are subunits of photosystem II reaction center with the corresponding molecular weights of 51000, 44000 and 34000. PSI70 is subunit I of photosystem I reaction center. Cyt /is cytochrome/ cyt is cytochrome b and b -flV is subunit IV of cytochrome b(,-f complex.

As shown in both Fig. 21 (A) and (B), there are five major protein complexes in the thylakoid-mem-brane network (1) the photosystem-11 core with bound inner antennae (collectively designated as PS II ), (2) the photosystem-I core with bound anteimae LHC I (collectively designated as PS I ), (3) the cytochrome (jg/complex, (4) theCFo CF, ATP-synthase and, finally (5) a separate, peripheral lightharvesting, chlorophyll-protein complex called LHC 11 that supplements the inner antennae bound to the photosystem-II reaction center. ... 

Fig. 4. (A) EPR spectra of TSF lla particles poised at -450 mV and after 90-s illumination at 295 or 220 K and measured at two different microwave powers. (B) shows effect of microwave power (P) on the amplitude of the photoinduced narrow (singlet) and doublet EPR signals at 7 K, Figure source Klimov, Dolan and Ke (1980) EPR properties of an intermediary electron acceptor (pheophytin) in photosystem II reaction centers at cryogenic temperatures. FEBS Lett 112 98,99 and Klimov, Dolan, Shaw and Ke (1980) Interaction between the intermediary electron acceptor (pheophytin) and a possible plastoquinone-lron complex in photosystem-ll reaction centers. Proc Nat Acad Sci, USA. 77 7228...

Fig. 9. Transient absorption spectra of isolated PS-II reaction-center complex at 7 K recorded at various time delays between 0.5 ps and 2.0 ns after a 100-nJ, 683-nm (A) or661-nm (B) excitation pulse. Monitoring wavelengths 543.5 and 558.5 nm used for the bleach-growth analysis (not shown) are marked with thin, dashed lines. Figure source Greenfield, Seibert and Wasielewski (1999) Time-resolved absorption changes of the pheophytin Qx band in isolated photosystem II reaction centers at 7 K Energy transfer and charge separation. J Phys Chem 103 8364-8374.

VV Klimov, E Dolan, ER Shaw and B Ke (1980) Interaction between the intermediary electron acceptor (pheophytin) and a possible plastoquinone-iron complex in photosystem II reaction center. Proc Nat Acad Sci, USA 77 7227-7231... 

Chapter 26 Photosystem-I Membrane, Complexes and Crystals II. Simplified Photosystem-I Reaction-Center Complexes... 

K Sonoike, H Hatanaka and S Katoh (1993) Small subunits of photosystem I reaction center complexes from Synechocystis elongatus. II. The PsaE gene product has a role to promote interaction between the terminal electron acceptor and ferredoxin. Bbchim Bbphys Acta 1141 52-57... 

The primary events of photosystem I have not yet been elucidated. Preliminary results indicate that the photochemistry occurs on the picosecond time scale. There is also some evidence to indicate that the primary electron acceptor may be a chlorophyll complex. Spectral changes associated with a number of intermediate acceptors have also been observed. Some of these acceptors have been identified as iron-sulfur proteins. Photosystem II reaction centers have a photoactive form of chlorophyll that absorbs at 680 nm. While very little else is known about the photoactive form in photosystem II, a great deal of information is available on the electron donors and acceptors of photosystem II. 

Akabori K, Tsukamoto H, Tsukihara J et al. Disintegration and reconstimtion of Photosystem II reaction center core complex. Preparation and characterization of three different types of subcomplexes. Biochim. Biophys. Acta 1988 932 345-357. 

In the Photosystem II reaction center (RCII) complex consisting of the Dl- and D2-subunits, cytochrome b-559 and the psbl gene product (1,2), excitation by a flash of light induces the oxidation of the primary donor P-680 (P) and the reduction of the primary acceptor pheo-phytin (H) within picoseconds (3). The primary radical pair (P H ) thus formed recombines rapidly with a half-lifetime of 30-40 ns, because of the absence of the primary quinone acceptor Qa (4,5). In part, the recombination results in an intermediary triplet state of P ( P) with a lifetime of 30 xs at 276 K (5). The quantum yield of P formation from P H (Ot) was found to be temperature dependent (232 at 276 K, 802 at 10 K) (5), similarly to what has been found for purple bacteria (6). 

Photoaffinity labels are an efficient tool for identification of inhibitor binding proteins in the photosynthetic electron transport chain. [ H]Azido-dinoseb, an azido-deri-vative of the phenolic herbicide dinoseb, was synthesized almost a decade ago and was shown to bind primarily to a 41 kDa protein (1,2). Contrary, labeling with azido-deri-vates of diuron-type herbicides revealed that these herbicides bind to a 32 kDa protein, which has now been recognized as the D-1 protein of the photosystem II reaction center core complex (see references in (3)). Tyrosine residues in positions 237 and 254 of the D-1 sequence were demonstrated to be the primary target of [ CJazido-monuron (3). The phenolic herbicide [ I]azido-ioxynil also labels predominantly the D-1 protein in position of Val249 and only in trace amounts a 41 kDa protein (4). 

Lane 1 demonstrates that [ H]2-acetoxymethyl-1,4-naphthoquinone primarilv labels a protein with an apparent molecular weight between 38 and 41 kDa. [ C]Azido-monuron labels preferentially the 32 kDa D-1 otein of the photosystem II reaction center core complex (lane 2), whereas [ C]azido-thiazolyliden-ketonitrile (6) simultaneously binds to the D-1 and D-2 proteins of photosystem II (lane 3). [ H]Azido-dinqseb tags D-1, D-2 and the same protein between 38 and 41 kDa which is labeled by [ H]2-acetoxymethyl-1,4-naphthoquinone (lane 4). Lanes 5 and 6 show immunoblots of thylakoid proteins with polyclonal antibodies raised against D-1 and D-2. It is evident that the 38-41 kDa protein does not react either with the D-1 or the D-2 antibody. It can be excluded, therefore, that the 38-41 kDa protein is a cross-linked product of a small polypeptide and D-1 or D-2. In Lane 7 marker proteins are depicted. 

The relation of the structure and organization of the Photosystem II reaction centers to those from Photosystem I or from the green or purple bacteria presents an interesting example of comparative biochemistry. Similarities between PS II and purple bacterial reaction centers include aspects of the reaction center proteins, the stoichiometry of chlorophyll and pheophytin in the reaction center and the complex of iron with quinones as the primary electron acceptor. In each of these respects the reaction centers of PS I or green bacteria, however, have no obvious similarity. 

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