Evidence that D1 Processing Is Required for Manganese Binding and Extrinsic Protein Assembly into Photosystem II

Roose, Johnna L.; Pakrasi, Himadri B.

doi:10.1074/jbc.m408458200

Cited by 106 publications

(98 citation statements)

References 46 publications

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“…In the vast majority of organisms containing PSII, the D1 protein is synthesized as a precursor protein (pD1 with a short peptide extension (8-16 amino acid residues) on the carboxy terminus (C-terminus) that is proteolytically removed during the assembly process [12,36]. Experimental deletion of this segment still allows functional assembly of the WOC, provided the native mature C-terminal α-carboxylate at position 344 is available.…”

Section: Psii Damage and Repairmentioning

confidence: 99%

Photoassembly of the water-oxidizing complex in photosystem II

Dasgupta

Ananyev

Dismukes

2008

Coordination Chemistry Reviews

165

121

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The light-driven steps in the biogenesis and repair of the inorganic core comprising the O 2 -evolving center of oxygenic photosynthesis (photosystem II water-oxidation complex, PSII-WOC) are reviewed. These steps, known collectively as photoactivation, involve the photoassembly of the free inorganic cofactors to the cofactor-depleted PSII-(apo-WOC) driven by light and produce the active O 2 -evolving core comprised of Mn 4 CaO x Cl y . We focus on the functional role of the inorganic components as seen through the competition with non-native cofactors ("inorganic mutants") on water oxidation activity, the rate of the photoassembly reaction, and on structural insights gained from EPR spectroscopy of trapped intermediates formed in the initial steps of the assembly reaction. A chemical mechanism for the initial steps in photoactivation is given that is based on these data. Photoactivation experiments offer the powerful insights gained from replacement of the native cofactors, which together with the recent X-ray structural data for the resting holoenzyme provide a deeper understanding of the chemistry of water oxidation. We also review some new directions in research that photoactivation studies have inspired that look at the evolutionary history of this remarkable catalyst.

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Section: Psii Damage and Repairmentioning

confidence: 99%

Photoassembly of the water-oxidizing complex in photosystem II

Dasgupta

Ananyev

Dismukes

2008

Coordination Chemistry Reviews

165

121

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“…Besides proteases, other factors have been discovered such as LPA19 that facilitates D1 protein precursor processing and interacts with the C-terminal region of the mature and precursor form of D1 (Wei et al, 2010). LPA19 is related to Psb27 present in both cyanobacteria and plants that appears to function in the assembly of the manganese cluster (Roose and Pakrasi, 2004). A second Psb27 homolog of Arabidopsis was identified as a PSII component and it is required for efficient repair of photodamaged PSII but is nonessential for PSII accumulation (Chen et al, 2006).…”

Section: Psii Assembly Degradation and Repairmentioning

confidence: 99%

Assembly of the Photosynthetic Apparatus

Rochaix

2011

Plant Physiology

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The primary reactions of photosynthesis are mediated by three protein complexes embedded in the thylakoid membranes of chloroplasts. These complexes are PSII, the cytochrome b 6 f complex (Cytb 6 f), and PSI, which are connected in series through the photosynthetic electron transport chain. Light energy captured by the light-harvesting systems of PSII (LHCII) and PSI (LHCI) is transferred to the reaction center chlorophylls to create a charge separation across the membrane. This leads to the formation of a strong oxidant on the donor side of PSII capable of splitting water into molecular oxygen, protons, and electrons. The electrons are transferred stepwise from PSII to the plastoquinone pool, Cytb 6 f, plastocyanin, and PSI where a second charge separation creates a strong reductant capable of reducing ferredoxin that subsequently reduces NADP + to NADPH. Besides this linear electron pathway there is a cyclic pathway in which electrons are cycled around PSI through the Cytb 6 f complex. The electron transfer reactions are coupled to proton pumping into the lumen space of the thylakoids and the resulting pH gradient drives the ATP synthase for ATP production. Ultimately NADPH and ATP are used for CO 2 assimilation by the Calvin-Benson cycle. Thylakoid membranes of land plants are organized in two domains, the grana stacks, comprising 80% of the membrane, and the stromal nonappressed membranes that connect different grana stacks. The photosynthetic complexes with exception of Cytb 6 f, are not distributed evenly through the thylakoid membrane system. Whereas PSII is mostly confined to the grana regions, PSI and ATP synthase are located in the stroma lamellae. Electron transfer between these complexes is mediated by the diffusible electron carriers plastoquinone and plastocyanin.A characteristic feature of the photosynthetic complexes is that they all consist of numerous chloroplast and nucleus-encoded subunits. In the case of PSII, PSI, and Cytb 6 f these complexes contain in addition pigments such as chlorophylls and xanthophylls as well as hemes, quinones, and iron-sulfur (Fe-S) centers that act as redox cofactors. Hence the biogenesis of the photosynthetic apparatus involves a concerted interplay between the chloroplast and nucleocytosolic genetic systems as well as a tight coordination between protein and pigment synthesis and insertion into the thylakoid membranes. Analysis of numerous mutants affected in photosynthetic activity in Chlamydomonas reinhardtii, Arabidopsis (Arabidopsis thaliana), and Zea mays has provided many new insights into the assembly of the photosynthetic complexes (Barkan and Goldschmidt-Clermont, 2000;Eberhard et al., 2008).A remarkable feature of photosynthetic organisms is their ability to adapt to changing light conditions, which is reflected in changes in the organization of the photosynthetic complexes. This Update reviews recent advances in our understanding of the assembly of these complexes and for some of them, their remodeling and/or reversible association into supercomplexes...

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“…Notably, the psb27 gene exhibits a strong temporal connectivity to other genes in SN IV (Table S3). The Psb27 protein is involved in the assembly of the water oxidation complex of photosystem II (25).…”

Section: Identification Of Genes With Oscillating Transcript Abundancementioning

confidence: 99%

Global transcriptomic analysis ofCyanothece51142 reveals robust diurnal oscillation of central metabolic processes

Stöckel

Welsh

Liberton

et al. 2008

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

Self Cite

174

259

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Cyanobacteria are photosynthetic organisms and are the only prokaryotes known to have a circadian lifestyle. Unicellular diazotrophic cyanobacteria such as Cyanothece sp. ATCC 51142 produce oxygen and can also fix atmospheric nitrogen, a process exquisitely sensitive to oxygen. To accommodate such antagonistic processes, the intracellular environment of Cyanothece oscillates between aerobic and anaerobic conditions during a day-night cycle. This is accomplished by temporal separation of the two processes: photosynthesis during the day and nitrogen fixation at night. Although previous studies have examined periodic changes in transcript levels for a limited number of genes in Cyanothece and other unicellular diazotrophic cyanobacteria, a comprehensive study of transcriptional activity in a nitrogen-fixing cyanobacterium is necessary to understand the impact of the temporal separation of photosynthesis and nitrogen fixation on global gene regulation and cellular metabolism. We have examined the expression patterns of nearly 5,000 genes in Cyanothece 51142 during two consecutive diurnal periods. Our analysis showed that Ϸ30% of these genes exhibited robust oscillating expression profiles. Interestingly, this set included genes for almost all central metabolic processes in Cyanothece 51142. A transcriptional network of all genes with significantly oscillating transcript levels revealed that the majority of genes encoding enzymes in numerous individual biochemical pathways, such as glycolysis, oxidative pentose phosphate pathway, and glycogen metabolism, were coregulated and maximally expressed at distinct phases during the diurnal cycle. These studies provide a comprehensive picture of how a physiologically relevant diurnal light-dark cycle influences the metabolism in a photosynthetic bacterium.circadian ͉ cyanobacteria ͉ microarray ͉ nitrogen fixation ͉ photosynthesis M any organisms, including animals, plants, fungi, and algae, have evolved an internal timing system to anticipate daily variations in their environment. Circadian behavior, the endogenous oscillation of processes with a period length of Ϸ1 day, is a fundamental aspect of biology that allows organisms to respond to their environment. The circadian clock controls a wide variety of biological activities, including sleep-wake cycles in mammals, leaf movements of plants, conidiation of Neurospora, and bioluminescence in dinoflagellates (1-4). In contrast, prokaryotes were long thought incapable of daily biological rhythms, because their generation times are typically shorter than a circadian period (5). During the past 15 years, numerous studies have shown that cyanobacteria, photosynthetic microbes, are the only prokaryotes known to have a circadian clock (6, 7). Although components of the circadian clock have been identified and analyzed in detail in cyanobacteria (8-10), the interactions between the clock and cellular physiology and metabolism have not been well elucidated.In cyanobacteria, oxygenic photosynthesis is a central metabolic process. In ad...

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Evidence that D1 Processing Is Required for Manganese Binding and Extrinsic Protein Assembly into Photosystem II

Cited by 106 publications

References 46 publications

Photoassembly of the water-oxidizing complex in photosystem II

Photoassembly of the water-oxidizing complex in photosystem II

Assembly of the Photosynthetic Apparatus

Global transcriptomic analysis ofCyanothece51142 reveals robust diurnal oscillation of central metabolic processes

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