scholarly journals Psb35 Protein Stabilizes the CP47 Assembly Module and Associated High-Light Inducible Proteins during the Biogenesis of Photosystem II in the Cyanobacterium Synechocystis sp. PCC6803

2020 ◽  
Author(s):  
Guillem Pascual-Aznar ◽  
Grzegorz Konert ◽  
Martina Bečková ◽  
Eva Kotabová ◽  
Zdenko Gardian ◽  
...  
Keyword(s):  
Photosystem Ii ◽  
High Light ◽  
Oxygenic Photosynthesis ◽  
Oxygen Evolving Complex ◽  
Primary Charge Separation ◽  
Light Regimes ◽  
Pulldown Assay ◽  
Antenna Module ◽  
Oxygen Evolving ◽  
Synechocystis Sp

Abstract Photosystem II (PSII) is a large membrane protein complex performing primary charge separation in oxygenic photosynthesis. The biogenesis of PSII is a complicated process that involves a coordinated linking of assembly modules in a precise order. Each such module consists of one large chlorophyll (Chl)-binding protein, number of small membrane polypeptides, pigments and other cofactors. We isolated the CP47 antenna module from the cyanobacterium Synechocystis sp. PCC 6803 and found that it contains a 11-kDa protein encoded by the ssl2148 gene. This protein was named Psb35 and its presence in the CP47 module was confirmed by the isolation of FLAG-tagged version of Psb35. Using this pulldown assay, we showed that the Psb35 remains attached to CP47 after the integration of CP47 into PSII complexes. However, the isolated Psb35-PSIIs were enriched with auxiliary PSII assembly factors like Psb27, Psb28-1, Psb28-2 and RubA while they lacked the lumenal proteins stabilizing the PSII oxygen-evolving complex. In addition, the Psb35 co-purified with a large unique complex of CP47 and photosystem I trimer. The absence of Psb35 led to a lower accumulation and decreased stability of the CP47 antenna module and associated high-light-inducible proteins but did not change the growth rate of the cyanobacterium under the variety of light regimes. Nevertheless, in comparison with WT, the Psb35-less mutant showed an accelerated pigment bleaching during prolonged dark incubation. The results suggest an involvement of Psb35 in the life cycle of cyanobacterial Chl-binding proteins, especially CP47.

scholarly journals Variation in Sulfide Tolerance of Photosystem II in Phylogenetically Diverse Cyanobacteria from Sulfidic Habitats

2004 ◽  
Vol 70 (2) ◽  
pp. 736-744 ◽  
Author(s):  
Scott R. Miller ◽  
Brad M. Bebout
Keyword(s):  
Photosystem Ii ◽  
Fluorescence Induction ◽  
Oxygenic Photosynthesis ◽  
Chlorophyll Fluorescence Induction ◽  
Oxygen Evolving Complex ◽  
Sulfide Toxicity ◽  
Molecular Phylogenetic ◽  
Dynamic Trait ◽  
Oxygen Evolving ◽  
Sulfide Tolerance

ABSTRACT Physiological and molecular phylogenetic approaches were used to investigate variation among 12 cyanobacterial strains in their tolerance of sulfide, an inhibitor of oxygenic photosynthesis. Cyanobacteria from sulfidic habitats were found to be phylogenetically diverse and exhibited an approximately 50-fold variation in photosystem II performance in the presence of sulfide. Whereas the degree of tolerance was positively correlated with sulfide levels in the environment, a strain's phenotype could not be predicted from the tolerance of its closest relatives. These observations suggest that sulfide tolerance is a dynamic trait primarily shaped by environmental variation. Despite differences in absolute tolerance, similarities among strains in the effects of sulfide on chlorophyll fluorescence induction indicated a common mode of toxicity. Based on similarities with treatments known to disrupt the oxygen-evolving complex, it was concluded that sulfide toxicity resulted from inhibition of the donor side of photosystem II.

scholarly journals Specific Incorporation of Polyunsaturated Fatty Acids into the sn-2 Position of Phosphatidylglycerol Accelerates Photodamage to Photosystem II under Strong Light

2021 ◽  
Vol 22 (19) ◽  
pp. 10432
Author(s):  
Haruhiko Jimbo ◽  
Koki Yuasa ◽  
Kensuke Takagi ◽  
Takashi Hirashima ◽  
Sumie Keta ◽  
...  
Keyword(s):  
Fatty Acids ◽  
Photosystem Ii ◽  
Polyunsaturated Fatty Acids ◽  
Membrane Lipids ◽  
Monounsaturated Fatty Acids ◽  
Oxygen Evolving Complex ◽  
Strong Light ◽  
Photosynthetic Organisms ◽  
Oxygen Evolving ◽  
Synechocystis Sp

Free fatty acids (FFAs) are generated by the reaction of lipases with membrane lipids. Generated polyunsaturated fatty acids (PUFAs) containing more than two double bonds have toxic effects in photosynthetic organisms. In the present study, we examined the effect of exogenous FFAs in the growth medium on the activity of photosystem II (PSII) under strong light in the cyanobacterium Synechocystis sp. PCC 6803 (Synechocystis). PUFAs but not monounsaturated fatty acids accelerated the rate of photodamage to PSII by inactivating electron transfer at the oxygen-evolving complex. Moreover, supplemented PUFAs were specifically incorporated into the sn-2 position of phosphatidylglycerol (PG), which usually contains C16 fatty acids at the sn-2 position in Synechocystis cells. The disruption of the gene for an acyl-ACP synthetase reduced the effect of PUFAs on the photoinhibition of PSII. Thus, the specific incorporation of PUFAs into PG molecules requires acyl-ACP synthetase and leads to an unstable PSII, thereby accelerating photodamage to PSII. Our results are a breakthrough into elucidating the molecular mechanism of the toxicity of PUFAs to photosynthetic organisms.

scholarly journals Photosystem II antenna modules CP43 and CP47 do not form a stable ‘no reaction centre complex’ in the cyanobacterium Synechocystis sp. PCC 6803

2022 ◽  
Author(s):  
Martina Bečková ◽  
Roman Sobotka ◽  
Josef Komenda
Keyword(s):  
Photosystem Ii ◽  
High Light ◽  
Oxygenic Photosynthesis ◽  
Reaction Centre ◽  
Wild Type ◽  
Migration Patterns ◽  
Separate Protein ◽  
Antenna Module ◽  
D2 Protein ◽  
Pcc 6803

AbstractThe repair of photosystem II is a key mechanism that keeps the light reactions of oxygenic photosynthesis functional. During this process, the PSII central subunit D1 is replaced with a newly synthesized copy while the neighbouring CP43 antenna with adjacent small subunits (CP43 module) is transiently detached. When the D2 protein is also damaged, it is degraded together with D1 leaving both the CP43 module and the second PSII antenna module CP47 unassembled. In the cyanobacterium Synechocystis sp. PCC 6803, the released CP43 and CP47 modules have been recently suggested to form a so-called no reaction centre complex (NRC). However, the data supporting the presence of NRC can also be interpreted as a co-migration of CP43 and CP47 modules during electrophoresis and ultracentrifugation without forming a mutual complex. To address the existence of NRC, we analysed Synechocystis PSII mutants accumulating one or both unassembled antenna modules as well as Synechocystis wild-type cells stressed with high light. The obtained results were not compatible with the existence of a stable NRC since each unassembled module was present as a separate protein complex with a mutually similar electrophoretic mobility regardless of the presence of the second module. The non-existence of NRC was further supported by isolation of the His-tagged CP43 and CP47 modules from strains lacking either D1 or D2 and their migration patterns on native gels.

Evolution of Oxygenic Photosynthesis

2017 ◽  
Author(s):  
Donald Eugene Canfield
Keyword(s):  
Photosystem Ii ◽  
Photosystem I ◽  
Evolutionary History ◽  
Oxygenic Photosynthesis ◽  
Oxygen Evolving Complex ◽  
History Of ◽  
Oxygen Evolving ◽  
Evolution Of Oxygen ◽  
Basic Constituent ◽  
Key Questions

This chapter discusses the evolution of oxygen-producing organisms by considering the evolution and assembly of its basic constituent parts. It focuses on the following key questions: (1) What is the evolutionary history of chlorophyll? (2) What are the evolutionary histories of photosystem I and photosystem II (PSII)? (3) What is the origin of the oxygen-evolving complex in PSII? And finally, (4) what is the evolutionary history of Rubisco? In addressing these, the chapter seeks to understand the complex path leading to the evolution of oxygenic photosynthesis on Earth. This event was one of the major transforming events in the history of life. With no oxygenic photosynthesis, there would be no oxygen in the atmosphere; there would also be no plants, no animals, and nobody to tell this story.

scholarly journals Photosystem II oxygen-evolving complex photoassembly displays an inverse H/D solvent isotope effect under chloride-limiting conditions

2019 ◽  
Vol 116 (38) ◽  
pp. 18917-18922 ◽  
Author(s):  
David J. Vinyard ◽  
Syed Lal Badshah ◽  
M. Rita Riggio ◽  
Divya Kaur ◽  
Annaliesa R. Fanguy ◽  
...  
Keyword(s):  
Amino Acid ◽  
Photosystem Ii ◽  
Isotope Effect ◽  
Water Oxidation ◽  
Oxygenic Photosynthesis ◽  
Oxygen Evolving Complex ◽  
Solvent Isotope Effect ◽  
Solvent Isotope ◽  
Oxygen Evolving ◽  
Protein Environment

Photosystem II (PSII) performs the solar-driven oxidation of water used to fuel oxygenic photosynthesis. The active site of water oxidation is the oxygen-evolving complex (OEC), a Mn4CaO5 cluster. PSII requires degradation of key subunits and reassembly of the OEC as frequently as every 20 to 40 min. The metals for the OEC are assembled within the PSII protein environment via a series of binding events and photochemically induced oxidation events, but the full mechanism is unknown. A role of proton release in this mechanism is suggested here by the observation that the yield of in vitro OEC photoassembly is higher in deuterated water, D2O, compared with H2O when chloride is limiting. In kinetic studies, OEC photoassembly shows a significant lag phase in H2O at limiting chloride concentrations with an apparent H/D solvent isotope effect of 0.14 ± 0.05. The growth phase of OEC photoassembly shows an H/D solvent isotope effect of 1.5 ± 0.2. We analyzed the protonation states of the OEC protein environment using classical Multiconformer Continuum Electrostatics. Combining experiments and simulations leads to a model in which protons are lost from amino acid that will serve as OEC ligands as metals are bound. Chloride and D2O increase the proton affinities of key amino acid residues. These residues tune the binding affinity of Mn2+/3+ and facilitate the deprotonation of water to form a proposed μ-hydroxo bridged Mn2+Mn3+ intermediate.

scholarly journals Structural Changes in the Acceptor Site of Photosystem II upon Ca2+/Sr2+ Exchange in the Mn4CaO5 Cluster Site and the Possible Long-Range Interactions

Biomolecules ◽  
2019 ◽  
Vol 9 (8) ◽  
pp. 371
Author(s):  
Koua
Keyword(s):  
Crystal Structure ◽  
Photosystem Ii ◽  
Long Range ◽  
Electron Acceptor ◽  
Structural Changes ◽  
Acceptor Site ◽  
Oxygen Evolving Complex ◽  
Long Range Interactions ◽  
Structural Perturbations ◽  
Oxygen Evolving

The Mn4CaO5 cluster site in the oxygen-evolving complex (OEC) of photosystem II (PSII) undergoes structural perturbations, such as those induced by Ca2+/Sr2+ exchanges or Ca/Mn removal. These changes have been known to induce long-range positive shifts (between +30 and +150 mV) in the redox potential of the primary quinone electron acceptor plastoquinone A (QA), which is located 40 Å from the OEC. To further investigate these effects, we reanalyzed the crystal structure of Sr-PSII resolved at 2.1 Å and compared it with the native Ca-PSII resolved at 1.9 Å. Here, we focus on the acceptor site and report the possible long-range interactions between the donor, Mn4Ca(Sr)O5 cluster, and acceptor sites.

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