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.

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 Targeted Random Mutagenesis To Identify Functionally Important Residues in the D2 Protein of Photosystem II in Synechocystis sp. Strain PCC 6803

2001 ◽  
Vol 183 (1) ◽  
pp. 145-154 ◽  
Author(s):  
Svetlana Ermakova-Gerdes ◽  
Zhenbao Yu ◽  
Wim Vermaas
Keyword(s):  
Photosystem Ii ◽  
Screening Method ◽  
Random Mutagenesis ◽  
Terminal Part ◽  
Photoautotrophic Growth ◽  
Intragenic Complementation ◽  
Novel Method ◽  
Α Helix ◽  
D2 Protein ◽  
Pcc 6803

ABSTRACT To identify important residues in the D2 protein of photosystem II (PSII) in the cyanobacterium Synechocystis sp. strain PCC 6803, we randomly mutagenized a region of psbDI (coding for a 96-residue-long C-terminal part of D2) with sodium bisulfite. Mutagenized plasmids were introduced into a Synechocystissp. strain PCC 6803 mutant that lacks both psbD genes, and mutants with impaired PSII function were selected. Nine D2 residues were identified that are important for PSII stability and/or function, as their mutation led to impairment of photoautotrophic growth. Five of these residues are likely to be involved in the formation of the QA-binding niche; these are Ala249, Ser254, Gly258, Ala260, and His268. Three others (Gly278, Ser283, and Gly288) are in transmembrane α-helix E, and their alteration leads to destabilization of PSII but not to major functional alterations of the remaining centers, indicating that they are unlikely to interact directly with cofactors. In the C-terminal lumenal tail of D2, only one residue (Arg294) was identified as functionally important for PSII. However, from the number of mutants generated it is likely that most or all of the 70 residues that are susceptible to bisulfite mutagenesis have been altered at least once. The fact that mutations in most of these residues have not been picked up by our screening method suggests that these mutations led to a normal photoautotrophic phenotype. A novel method of intragenic complementation in Synechocystissp. strain PCC 6803 was developed to facilitate genetic analysis ofpsbDI mutants containing several amino acid changes in the targeted domain. Recombination between genome copies in the same cell appears to be much more prevalent in Synechocystis sp. strain PCC 6803 than was generally assumed.

Photosystem II activity of wild type Synechocystis PCC 6803 and its mutants with different plastoquinone pool redox states

2016 ◽  
Vol 81 (8) ◽  
pp. 858-870
Author(s):  
O. V. Voloshina ◽  
Y. V. Bolychevtseva ◽  
F. I. Kuzminov ◽  
M. Y. Gorbunov ◽  
I. V. Elanskaya ◽  
...  
Keyword(s):  
Photosystem Ii ◽  
Wild Type ◽  
Synechocystis Pcc 6803 ◽  
Redox States ◽  
Plastoquinone Pool ◽  
Photosystem Ii Activity ◽  
Pcc 6803

scholarly journals Site-directed mutations at D1-His198 and D1-Thr179 of photosystem II in Synechocystis sp. PCC 6803: deciphering the spectral properties of the PSII reaction centre

2007 ◽  
Vol 363 (1494) ◽  
pp. 1197-1202 ◽  
Author(s):  
Eberhard Schlodder ◽  
William J Coleman ◽  
Peter J Nixon ◽  
Rachel O Cohen ◽  
Thomas Renger ◽  
...  
Keyword(s):  
Photosystem Ii ◽  
Difference Spectrum ◽  
Axial Ligand ◽  
Reaction Centre ◽  
Wild Type ◽  
Difference Spectra ◽  
Exciton Transition ◽  
Special Pair ◽  
First Approximation ◽  
Absorbance Difference

Site-directed mutations were constructed in photosystem II of Synechocystis sp. PCC6803 in which the axial ligand, D1-His198, of special pair chlorophyll P D1 was replaced with Gln and where D1-Thr179, which overlies monomeric chlorophyll Chl D1 , was replaced with His. The D1-His198Gln mutation produces a 3 nm displacement to the blue of the bleaching minimum in the Soret and in the Qy region of the – absorbance difference spectrum. To a first approximation, the bleaching can be assigned to the low-energy exciton transition of the special pair chlorophylls P D1 /P D2 . The D1-Thr179His mutation produces a 2 nm displacement to the red of the bleaching minimum in the Qy region of the ( 3 P– 1 P) absorbance difference spectrum. Analysis of the flash-induced – and ( 3 P– 1 P) absorbance difference spectra of both mutants compared with wild-type at 80 K indicate that the cation of the oxidized donor P + is predominantly localized on the chlorophyll P D1 of the special pair and that the reaction centre triplet state, produced upon charge recombination from 3 [P + Pheo − ], when the primary quinone electron acceptor Q A is doubly reduced, is primarily localized on Chl D1 .

scholarly journals A reversibly induced CRISPRi system targeting Photosystem II in the cyanobacterium Synechocystis sp. PCC 6803

2020 ◽  
Author(s):  
Deng Liu ◽  
Virginia M. Johnson ◽  
Himadri B. Pakrasi
Keyword(s):  
Photosystem Ii ◽  
Sole Carbon Source ◽  
Model Organism ◽  
Inducible Promoter ◽  
New Strategy ◽  
Photosynthetic Complexes ◽  
Promoter System ◽  
Synechocystis Sp ◽  
D2 Protein ◽  
Pcc 6803

ABSTRACTThe cyanobacterium Synechocystis sp. PCC 6803 is used as a model organism to study photosynthesis, as it can utilize glucose as the sole carbon source to support its growth under heterotrophic conditions. CRISPR interference (CRISPRi) has been widely applied to repress the transcription of genes in a targeted manner in cyanobacteria. However, a robust and reversible induced CRISPRi system has not been explored in Synechocystis 6803 to knock down and recover the expression of a targeted gene. In this study, we built a tightly controlled chimeric promoter, PrhaBAD-RSW, in which a theophylline responsive riboswitch was integrated into a rhamnose-inducible promoter system. We applied this promoter to drive the expression of ddCpf1 (DNase-dead Cpf1 nuclease) in a CRISPRi system and chose the PSII reaction center gene psbD (D2 protein) to target for repression. psbD was specifically knocked down by over 95% of its native expression, leading to severely inhibited Photosystem II activity and growth of Synechocystis 6803 under photoautotrophic conditions. Significantly, removal of the inducers rhamnose and theophylline reversed repression by CRISPRi. Expression of PsbD recovered following release of repression, coupled with increased Photosystem II content and activity. This reversibly induced CRISPRi system in Synechocystis 6803 represents a new strategy for study of the biogenesis of photosynthetic complexes in cyanobacteria.

scholarly journals CpcM Posttranslationally Methylates Asparagine-71/72 of Phycobiliprotein Beta Subunits in Synechococcus sp. Strain PCC 7002 and Synechocystis sp. Strain PCC 6803

2008 ◽  
Vol 190 (14) ◽  
pp. 4808-4817 ◽  
Author(s):  
Gaozhong Shen ◽  
Heidi S. Leonard ◽  
Wendy M. Schluchter ◽  
Donald A. Bryant
Keyword(s):  
Light Stress ◽  
Fluorescence Emission ◽  
High Light ◽  
State Transitions ◽  
Comparative Genomic ◽  
Beta Subunits ◽  
Wild Type ◽  
Light Harvesting Complexes ◽  
Type Strains ◽  
Pcc 6803

ABSTRACT Cyanobacteria produce phycobilisomes, which are macromolecular light-harvesting complexes mostly assembled from phycobiliproteins. Phycobiliprotein beta subunits contain a highly conserved γ-N-methylasparagine residue, which results from the posttranslational modification of Asn71/72. Through comparative genomic analyses, we identified a gene, denoted cpcM, that (i) encodes a protein with sequence similarity to other S-adenosylmethionine-dependent methyltransferases, (ii) is found in all sequenced cyanobacterial genomes, and (iii) often occurs near genes encoding phycobiliproteins in cyanobacterial genomes. The cpcM genes of Synechococcus sp. strain PCC 7002 and Synechocystis sp. strain PCC 6803 were insertionally inactivated. Mass spectrometric analyses of phycobiliproteins isolated from the mutants confirmed that the CpcB, ApcB, and ApcF were 14 Da lighter than their wild-type counterparts. Trypsin digestion and mass analyses of phycobiliproteins isolated from the mutants showed that tryptic peptides from phycocyanin that included Asn72 were also 14 Da lighter than the equivalent peptides from wild-type strains. Thus, CpcM is the methyltransferase that modifies the amide nitrogen of Asn71/72 of CpcB, ApcB, and ApcF. When cells were grown at low light intensity, the cpcM mutants were phenotypically similar to the wild-type strains. However, the mutants were sensitive to high-light stress, and the cpcM mutant of Synechocystis sp. strain PCC 6803 was unable to grow at moderately high light intensities. Fluorescence emission measurements showed that the ability to perform state transitions was impaired in the cpcM mutants and suggested that energy transfer from phycobiliproteins to the photosystems was also less efficient. The possible functions of asparagine N methylation of phycobiliproteins are discussed.

Sign in / Sign up

Export Citation Format

Share Document