Comparison of Cytochrome b-559 Content in Photosystem II Complexes from Spinach and Synechocystis Species PCC 6803

Gm, MacDONALD; Rj, Boerner; Rm, Everly; Wa, Cramer; Rj, Debus; Ba, Barry

doi:10.1021/bi00180a037

Cited by 41 publications

(45 citation statements)

References 67 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The ratio r of the values for cytochrome b559 and the non heme iron centers is 1.63 which closely resembles with a cytochrome b559 content of 1.8 per PS II detected in the same sample by optical difference spectroscopy (data not shown) and using a difference extinction coefficient of 17.5 mM -1.cm -1 [34]. Based on these data and taking into account the possibility of a loss during the isolation procedure [35] PS II membrane fragments are inferred to contain two cytochrome b559 per PS II. However, it has to be emphasized that the M6ssbauer results could be affected by contamination by a small fraction of PSI which is rich in non heme iron due to the Fe-S centers.…”

Section: M6ssbauer Measurementssupporting

confidence: 80%

Isolation and properties of PS II membrane fragments depleted of the non heme iron center

et al. 1996

View full text Add to dashboard Cite

Section: M6ssbauer Measurementssupporting

confidence: 80%

Isolation and properties of PS II membrane fragments depleted of the non heme iron center

et al. 1996

View full text Add to dashboard Cite

“…Cytochrome b 559 is low potential in these preparations and already oxidized (20,31). Redox-active tyrosine D is preoxidized in both wildtype (12)(13)(14) and mutant PSII and does not significantly contribute to the light-minus-dark difference spectrum (Fig.…”

Section: Difference Ft-ir Studies Of Oxygen-evolving Wild-type and Dementioning

confidence: 99%

Alterations in Carboxylate Ligation at the Active Site of Photosystem II

Steenhuis¹,

Hutchison

Barry

1999

Journal of Biological Chemistry

Self Cite

View full text Add to dashboard Cite

Photosystem II (PSII) is the photosynthetic enzyme catalyzing the oxidation of water and reduction of plastoquinone (Q). This reaction occurs at a catalytic site containing four manganese atoms and cycling among five oxidation states, the S n states, where n refers to the number of oxidizing equivalents stored. Biochemical and spectroscopic techniques have been used previously to conclude that aspartate 170 in the D1 subunit influences the structure and function of the PSII active site (Boerner, R. J., Nguyen, A. P., Barry, B. A., and Debus, R. J. (1992) Biochemistry 31, 6660 -6672). Substitution of glutamate for aspartate 170 resulted in an assembled manganese cluster, which was capable of enzymatic turnover, but at lower steady-state oxygen evolution rates. Here, we obtained the difference (lightminus-dark) Fourier transform IR spectrum associated with the S 2 Q ؊ -minus-S 1 Q transition by illumination of oxygen-evolving wild-type and DE170D1 PSII preparations at 200 K. These spectra are known to be dominated by contributions from carboxylic acid and carboxylate residues that are close to or ligating the manganese cluster. Substitution of glutamate for aspartate 170 results in alterations in the S 2 Q ؊ -minus-S 1 Q spectrum; the alterations are consistent with a change in carboxylate coordination to manganese or calcium. In particular, the spectra are consistent with a shift from bridging/ bidentate carboxylates in wild-type PSII to unidentate carboxylate ligation in DE170D1 PSII.Photosystem II (PSII) 1 is the photosynthetic reaction center that is responsible for the light-driven oxidation of water and the reduction of quinone in plants, green algae, and cyanobacteria. The catalytic site contains a tetranuclear manganese cluster, and the catalytic cycle of water oxidation has been proposed to consist of five oxidation states (S n ) called the JoliotKok S states. The subscript n refers to the number of oxidizing equivalents stored at the active site. Absorption of four photons and four corresponding charge separations are necessary to complete one catalytic cycle. Each cycle results in the oxidation of two water molecules to form one molecule of molecular oxygen and four protons. Calcium is required for oxygen evolution and may be bound in proximity to the manganese cluster (reviewed in Refs. 1 and 2).Many studies of PSII have focused on the S 2 state (for review, see Ref. 3). Dark adaptation at room temperature sets the catalytic center to the S 1 state because S 0 converts to S 1 by reduction of tyrosine radical, D ⅐ (4, 5). Two different EPR signals, a g ϭ 2 multiline signal (6) and a g ϭ 4.1 signal (7), are observed from the S 2 state. Illumination of plant or cyanobacterial PSII at 200 K results in the formation of the g ϭ 2 multiline EPR signal (for examples, see Refs. 6 and 8) and an EPR signal from Fe 2ϩ Q A Ϫ (9). The S 1 -to-S 2 transition is associated with oxidation of manganese, probably from Mn 3ϩ to Mn 4ϩ (reviewed in Ref. 10). Recently, we have obtained the difference FT-IR spectrum associate...

show abstract

“…In plants, these extrinsic proteins, the 18-kDa, 24-kDa, and psbO (or the 33-kDa, manganese stabilizing protein), are essential for maximal oxygen evolution under physiological conditions (6). Both cyanobacterial and plant PSII contain an intrinsic cytochrome b 559 (7), whereas cyanobacterial PSII also contains an extrinsic cytochrome c 550 (2, 8 -11). The structure of cyanobacterial PSII has been solved to 1.9-Å resolution (Ref.…”

Section: And References Therein)mentioning

confidence: 99%

N-Formylkynurenine as a Marker of High Light Stress in Photosynthesis

Dreaden

Chen²,

Rexroth³

et al. 2011

Journal of Biological Chemistry

Self Cite

View full text Add to dashboard Cite

Photosystem II (PSII) is the membrane protein complex that catalyzes the photo-induced oxidation of water at a manganesecalcium active site. Light-dependent damage and repair occur in PSII under conditions of high light stress. The core reaction center complex is composed of the D1, D2, CP43, and CP47 intrinsic polypeptides. In this study, a new chromophore formed from the oxidative post-translational modification of tryptophan is identified in the CP43 subunit. Tandem mass spectrometry peptide sequencing is consistent with the oxidation of the CP43 tryptophan side chain, Trp-365, to produce N-formylkynurenine (NFK). Characterization with ultraviolet visible absorption and ultraviolet resonance Raman spectroscopy supports this assignment. An optical assay suggests that the yield of NFK increases 2-fold (2.2 ؎ 0.5) under high light illumination. A concomitant 2.4 ؎ 0.5-fold decrease is observed in the steady-state rate of oxygen evolution under the high light conditions. NFK is the product formed from reaction of tryptophan with singlet oxygen, which can be produced under high light stress in PSII. Reactive oxygen species reactions lead to oxidative damage of the reaction center, D1 protein turnover, and inhibition of electron transfer. Our results are consistent with a role for the CP43 NFK modification in photoinhibition.Oxygenic photosynthesis is the enzyme-catalyzed conversion of light energy to biochemical energy, and this process occurs in the membranes of plants, algae, and cyanobacteria. In oxygenic photosynthesis, photosystem II (PSII) 4 catalyzes the light-driven oxidation of water and reduction of plastoquinone. On the acceptor side of PSII, electrons are transferred sequentially to two quinone molecules, Q A and Q B (1). On the donor side, a Mn 4 Ca active site is the binding site for water and the site of oxygen production. Each monomer is composed of 20 protein subunits, chlorophylls, carotenoids, and redox-active plastoquinones (2, 3). Calcium and chloride are required for activity under physiological conditions (4). The chloride binding site has been assigned near the active site (2, 3).The D1, D2, CP43, and CP47 polypeptides form the intrinsic core complex of PSII. The D1 and D2 membrane spanning proteins bind the electron transfer cofactors active in water oxidation (2, 3). This central heterodimeric core is symmetrically flanked by the CP43 and CP47 proteins, which bind light-harvesting antennae chlorophyll (Chl) molecules (5). Each of these core polypeptides is composed of intrinsic membrane-spanning helices, as well as several hydrophilic loops that protrude into the interior lumen of the thylakoid membrane (2, 3). The lumenal loop regions of CP43 have been implicated as important in assembly and protection from photoinhibition (see Ref. and references therein).The active site of water oxidation, the Mn 4 Ca cluster, is located on the lumenal surface and is protected by three extrinsic polypeptides (6). In plants, these extrinsic proteins, the 18-kDa, 24-kDa, and psbO (or the 33-kDa, manganes...

show abstract

Comparison of Cytochrome b-559 Content in Photosystem II Complexes from Spinach and Synechocystis Species PCC 6803

Cited by 41 publications

References 67 publications

Isolation and properties of PS II membrane fragments depleted of the non heme iron center

Isolation and properties of PS II membrane fragments depleted of the non heme iron center

Alterations in Carboxylate Ligation at the Active Site of Photosystem II

N-Formylkynurenine as a Marker of High Light Stress in Photosynthesis

Contact Info

Product

Resources

About