Photoactivation of Oxygen‐evolving System in Dark‐grown Spruce Seedlings

Oku, Tatsuo; Tomita, Giiti

doi:10.1111/j.1399-3054.1976.tb03987.x

Cited by 36 publications

(14 citation statements)

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“…Photoactivation of the water-oxidation system has been widely reported for Imf3 angiosperm leaves (11,23), dark-grown gymnosperm leaves (16), dark-grown algal cells (7), Mn-deficient algal cells (5), NH20H-extracted cyanobacterial cells (6), and Tris-extracted chloroplasts (26). The process can be driven by continuous light or by a series of short (as) flashes with intervals of a few seconds, indicative of the involvewr Xnt of a multiquantum process (6,7,11).…”

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Changes in Protein Composition and Mn Abundance in Photosystem II Particles on Photoactivation of the Latent O₂-Evolving System in Flash-Grown Wheat Leaves

Ono¹,

Kajikawa²,

Inoue³

1986

Plant Physiol.

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Protein composition and Mn abundance were compared between the two photosystem II (PSII) particle preparations obtained before and after photoactivation of the latent 02-evolving system in intermittently flashed wheat leaves. The following results have been obtained: (a) In the last 5 years, biochemical characterization of the O2-evolving apparatus has advanced dramatically. Initiated by the successful preparation of 0-evolving PSII particles from spinach (3,12,25), intensive studies have been revealing the structural relationships between the PSII reaction center (24, 27) and the 02-evolving apparatus, in particular the roles of the three extrinsic proteins (33, 24, and 16 kD). The 16 and 24 kD proteins are considered to play regulatory roles in 02-evolution by affording high affinity binding for Cl-and Ca2+ (plus Cl-), respectively (1, 2, 9), while the 33 kD protein seems to play a role in stabilizing the Mn atoms in the 02-evolving center (19,20) and thereby enabling them to carry out the linear 4-step oxidation of water (22).We report here some of the changes in biochemical properties ofthe PSII particles that occur when Imfwheat leaves are exposed to continuous light to activate the 02-evolving centers. It was clearly shown that during photoactivation the 16 and 24 kD proteins are integrated into the 02-evolving apparatus, concomitantly with incorporation of 3 Mm atoms into the apparatus, to attain catalytically functional states.

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Changes in Protein Composition and Mn Abundance in Photosystem II Particles on Photoactivation of the Latent O₂-Evolving System in Flash-Grown Wheat Leaves

Ono¹,

Kajikawa²,

Inoue³

1986

Plant Physiol.

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“…All of the photoactivation studies reported to date have been performed by using PSII cores (26), PSII membranes (19,20), or larger, native-like preparation (18,27,28). The possibility of oxygen evolution from smaller PSII subcore complexes has not been demonstrated previously, although Rögner et al (29) had shown that a PSII complex can form within the photosynthetic membrane in a CP43 deletion mutant of Synechocystis that This paper was submitted directly (Track II) to the PNAS office.…”

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confidence: 99%

Photoassembly of the manganese cluster and oxygen evolution from monomeric and dimeric CP47 reaction center photosystem II complexes

Büchel

Barber

Ananyev

et al. 1999

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

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Isolated subcomplexes of photosystem II from spinach (CP47RC), composed of D1, D2, cytochrome b 559, CP47, and a number of hydrophobic small subunits but devoid of CP43 and the extrinsic proteins of the oxygen-evolving complex, were shown to reconstitute the Mn 4Ca1Clx cluster of the water-splitting system and to evolve oxygen. The photoactivation process in CP47RC dimers proceeds by the same two-step mechanism as observed in PSII membranes and exhibits the same stoichiometry for Mn 2؉ , but with a 10-fold lower affinity for Ca 2؉ and an increased susceptibility to photodamage. After the lower Ca 2؉ affinity and the 10-fold smaller absorption cross-section for photons in CP47 dimers is taken into account, the intrinsic rate constant for the ratelimiting calcium-dependent dark step is indistinguishable for the two systems. The monomeric form of CP47RC also showed capacity to photoactivate and catalyze water oxidation, but with lower activity than the dimeric form and increased susceptibility to photodamage. After optimization of the various parameters affecting the photoactivation process in dimeric CP47RC subcores, 18% of the complexes were functionally reconstituted and the quantum efficiency for oxygen production by reactivated centers approached 96% of that observed for reconstituted photosystem II-enriched membranes. G reen plants, algae, and cyanobacteria are unique in their ability to catalyze the oxidation of water to molecular oxygen by using light energy. This process is carried out by photosystem II (PSII), a protein complex embedded in the thylakoid membrane. It consists of more than 25 different subunits, binds a large number of pigments, and contains a photochemical reaction center for light-driven charge separation (see recent reviews in refs. 1-5). In this paper we show that oxygen evolution is possible from a subcomplex composed of a small number of these subunits after reconstituting the catalytic inorganic center.The innermost part of PSII consists of the reaction center (RC), which, when isolated, is composed of the D1 and D2 proteins, where the primary charge separation occurs, the psbI gene product, and the ␣-and ␤-subunits of cytochrome b 559 (6). Closely associated with the RC are the chlorophyll-and ␤-carotene-binding ''inner antenna'' proteins CP43 and CP47 and a range of small, hydrophobic polypeptides, which, together, comprise the PSII core complex. Several of these subunits have been proposed to contain residues essential for water oxidation.Water oxidation occurs at a catalytic site containing a tetramanganese cluster, one calcium ion, and an indeterminate number of chloride ions in association with tyrosyl residue Tyr161 (Y Z ) located in the D1 protein. Evidence to date indicates that the majority of ligands binding the manganese cluster are located in the D1 protein (7-10). The oxidized tyrosyl radical Y Z⅐ is reduced by electrons from the manganese cluster after being oxidized by the light-driven charge separation. This charge separation involves the oxidation of the primary ele...

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“…Stringent conditions for the in situ hybridization were determined by hybridizing the probes with pine chloroplasts (27), cells of pine-associated bacteria (the bacteria under study and Mycobacterium sp. [21]), and two control bacteria (E. coli DH5␣ and Lactobacillus delbrueckii subsp.…”

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Detection of Intracellular Bacteria in the Buds of Scotch Pine ( Pinus sylvestris L.) by In Situ Hybridization

Pirttilä

Laukkanen²,

Pospiech

et al. 2000

Appl Environ Microbiol

172

109

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Photoactivation of Oxygen‐evolving System in Dark‐grown Spruce Seedlings

Cited by 36 publications

References 9 publications

Changes in Protein Composition and Mn Abundance in Photosystem II Particles on Photoactivation of the Latent O₂-Evolving System in Flash-Grown Wheat Leaves

Changes in Protein Composition and Mn Abundance in Photosystem II Particles on Photoactivation of the Latent O₂-Evolving System in Flash-Grown Wheat Leaves

Photoassembly of the manganese cluster and oxygen evolution from monomeric and dimeric CP47 reaction center photosystem II complexes

Detection of Intracellular Bacteria in the Buds of Scotch Pine ( Pinus sylvestris L.) by In Situ Hybridization

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Photoactivation of Oxygen‐evolving System in Dark‐grown Spruce Seedlings

Cited by 36 publications

References 9 publications

Changes in Protein Composition and Mn Abundance in Photosystem II Particles on Photoactivation of the Latent O2-Evolving System in Flash-Grown Wheat Leaves

Changes in Protein Composition and Mn Abundance in Photosystem II Particles on Photoactivation of the Latent O2-Evolving System in Flash-Grown Wheat Leaves

Photoassembly of the manganese cluster and oxygen evolution from monomeric and dimeric CP47 reaction center photosystem II complexes

Detection of Intracellular Bacteria in the Buds of Scotch Pine ( Pinus sylvestris L.) by In Situ Hybridization

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Changes in Protein Composition and Mn Abundance in Photosystem II Particles on Photoactivation of the Latent O₂-Evolving System in Flash-Grown Wheat Leaves

Changes in Protein Composition and Mn Abundance in Photosystem II Particles on Photoactivation of the Latent O₂-Evolving System in Flash-Grown Wheat Leaves