scholarly journals In vitro reconstitution of the photosystem I light-harvesting complex LHCI-730: Heterodimerization is required for antenna pigment organization

1997 ◽  
Vol 94 (14) ◽  
pp. 7667-7672 ◽  
Author(s):  
V. H. R. Schmid ◽  
K. V. Cammarata ◽  
B. U. Bruns ◽  
G. W. Schmidt
Keyword(s):  
Photosystem I ◽  
Light Harvesting ◽  
Light Harvesting Complex ◽  
In Vitro Reconstitution ◽  
Antenna Pigment

scholarly journals The light-harvesting complexes of higher-plant Photosystem I: Lhca1/4 and Lhca2/3 form two red-emitting heterodimers

2011 ◽  
Vol 433 (3) ◽  
pp. 477-485 ◽  
Author(s):  
Emilie Wientjes ◽  
Roberta Croce
Keyword(s):  
Photosystem I ◽  
Light Harvesting ◽  
Fluorescence Emission ◽  
Light Response ◽  
Native State ◽  
Higher Plant ◽  
Light Harvesting Complexes ◽  
Light Harvesting Complex ◽  
Wavelength Emission

The outer antenna of higher-plant PSI (Photosystem I) is composed of four complexes [Lhc (light-harvesting complex) a1–Lhca4] belonging to the light-harvesting protein family. Difficulties in their purification have so far prevented the determination of their properties and most of the knowledge about Lhcas has been obtained from the study of the in vitro reconstituted antennas. In the present study we were able to purify the native complexes, showing that Lhca2/3 and Lhca1/4 form two functional heterodimers. Both dimers show red-fluorescence emission with maxima around 730 nm, as in the intact PSI complex. This indicates that the dimers are in their native state and that LHCI-680, which was previously assumed to be part of the PSI antenna, does not represent the native state of the system. The data show that the light-harvesting properties of the two dimers are functionally identical, concerning absorption, long-wavelength emission and fluorescence quantum yield, whereas they differ in their high-light response. Implications of the present study for the understanding of the energy transfer process in PSI are discussed. Finally, the comparison of the properties of the native dimers with those of the reconstituted complexes demonstrates that all of the major properties of the Lhcas are reproduced in the in vitro systems.

scholarly journals Plant Physiology, 2021 Functional redox links between lumen thiol oxidoreductase1 and serine/threonine-protein kinase STN7

2021 ◽  
Author(s):  
Jianghao Wu ◽  
Liwei Rong ◽  
Weijun Lin ◽  
Lingxi Kong ◽  
Dengjie Wei ◽  
...  
Keyword(s):  
Protein Kinase ◽  
Disulfide Bonds ◽  
Kinase Activity ◽  
Light Harvesting ◽  
Photosynthetic Electron Transport ◽  
State Transitions ◽  
Light Harvesting Complex ◽  
Light Harvesting Complex Ii

Abstract In response to changing light quantity and quality, photosynthetic organisms perform state transitions, a process which optimizes photosynthetic yield and mitigates photo-damage. The serine/threonine-protein kinase STN7 phosphorylates the light-harvesting complex of photosystem II (PSII; light-harvesting complex II), which then migrates from PSII to photosystem I (PSI), thereby rebalancing the light excitation energy between the photosystems and restoring the redox poise of the photosynthetic electron transport chain. Two conserved cysteines forming intra- or intermolecular disulfide bonds in the lumenal domain (LD) of STN7 are essential for the kinase activity although it is still unknown how activation of the kinase is regulated. In this study, we show lumen thiol oxidoreductase 1 (LTO1) is co-expressed with STN7 in Arabidopsis (Arabidopsis thaliana) and interacts with the LD of STN7 in vitro and in vivo. LTO1 contains thioredoxin (TRX)-like and vitamin K epoxide reductase domains which are related to the disulfide-bond formation system in bacteria. We further show that the TRX-like domain of LTO1 is able to oxidize the conserved lumenal cysteines of STN7 in vitro. In addition, loss of LTO1 affects the kinase activity of STN7 in Arabidopsis. Based on these results, we propose that LTO1 helps to maintain STN7 in an oxidized active state in state 2 through redox interactions between the lumenal cysteines of STN7 and LTO1.

Structure of plant photosystem I‐light harvesting complex I supercomplex at 2.4 Å resolution

2021 ◽  
Author(s):  
Jie Wang ◽  
Long‐Jiang Yu ◽  
Wenda Wang ◽  
Qiujing Yan ◽  
Tingyun Kuang ◽  
...  
Keyword(s):  
Photosystem I ◽  
Complex I ◽  
Light Harvesting ◽  
Light Harvesting Complex

Cloning of a pea cDNA encoding a polypeptide of the light-harvesting complex associated with photosystem I using a monoclonal antibody

1995 ◽  
Vol 27 (4) ◽  
pp. 821-824 ◽  
Author(s):  
Martin E. Cannell ◽  
Alison J. Mitchell ◽  
Sharon McCready ◽  
James A. Callow ◽  
Jonathan R. Green
Keyword(s):  
Monoclonal Antibody ◽  
Photosystem I ◽  
Light Harvesting ◽  
Light Harvesting Complex

scholarly journals Identification of parallel pH- and zeaxanthin-dependent quenching of excess energy in LHCSR3 in Chlamydomonas reinhardtii

2020 ◽  
Author(s):  
Julianne M. Troiano ◽  
Federico Perozeni ◽  
Raymundo Moya ◽  
Luca Zuliani ◽  
Kwangryul Baek ◽  
...  
Keyword(s):  
Chlamydomonas Reinhardtii ◽  
Light Harvesting ◽  
Complex Stress ◽  
Excess Energy ◽  
Photochemical Quenching ◽  
Light Harvesting Complexes ◽  
Light Harvesting Complex ◽  
Non Photochemical Quenching

AbstractUnder high light conditions, oxygenic photosynthetic organisms avoid photodamage by thermally dissipating excess absorbed energy, which is called non-photochemical quenching (NPQ). In green algae, a chlorophyll and carotenoid-binding protein, light-harvesting complex stress-related (LHCSR3), detects excess energy via pH and serves as a quenching site. However, the mechanisms by which LHCSR3 functions have not been determined. Using a combined in vivo and in vitro approach, we identify two parallel yet distinct quenching processes, individually controlled by pH and carotenoid composition, and their likely molecular origin within LHCSR3 from Chlamydomonas reinhardtii. The pH-controlled quenching is removed within a mutant LHCSR3 that lacks the protonable residues responsible for sensing pH. Constitutive quenching in zeaxanthin-enriched systems demonstrates zeaxanthin-controlled quenching, which may be shared with other light-harvesting complexes. We show that both quenching processes prevent the formation of damaging reactive oxygen species, and thus provide distinct timescales and mechanisms of protection in a changing environment.

scholarly journals Spatial relationship of photosystem I, photosystem II, and the light-harvesting complex in chloroplast membranes.

1977 ◽  
Vol 73 (2) ◽  
pp. 400-418 ◽  
Author(s):  
P A Armond ◽  
L A Staehelin ◽  
C J Arntzen
Keyword(s):  
Particle Size ◽  
Photosystem Ii ◽  
Photosystem I ◽  
Light Harvesting ◽  
Particle Density ◽  
Unit Size ◽  
Fracture Face ◽  
Photosynthetic Unit ◽  
Light Harvesting Complex ◽  
Chloroplast Membrane

We have previously demonstrated (Armond, P. A., C. J. Arntzen, J.-M. Briantais, and C. Vernotte. 1976. Arch. Biochem. Biophys. 175:54-63; and Davis, D. J., P. A. Armond, E. L. Gross, and C. J. Arntzen. 1976. Arch. Biochem. Biophys. 175:64-70) that pea seedlings which were exposed to intermittent illumination contained incompletely developed chloroplasts. These plastids were photosynthetically competent, but did not contain grana. We now demonstrate that the incompletely developed plastids have a smaller photosynthetic unit size; this is primarily due to the absence of a major light-harvesting pigment-protein complex which is present in the mature membranes. Upon exposure of intermittent-light seedlings to continuous white light for periods up to 48 h, a ligh-harvesting chlorophyll-protein complex was inserted into the chloroplast membrane with a concomitant appearance of grana stacks and an increase in photosynthetic unit size. Plastid membranes from plants grown under intermediate light were examined by freeze-fracture electron microscopy. The membrane particles on both the outer (PF) and inner (EF) leaflets of the thylakoid membrane were found to be randomly distributed. The particle density of the PF fracture face was approx. four times that of the EF fracture face. While only small changes in particle density were observed during the greening process under continuous light, major changes in particle size were noted, particularly in the EF particles of stacked regions (EFs) of the chloroplast membrane. Both the changes in particle size and an observed aggregation of the EF particles into the newly stacked regions of the membrane were correlated with the insertion of light-harvesting pigment-protein into the membrane. Evidence is presented for identification of the EF particles as the morphological equivalent of a "complete" photosystem II complex, consisting of a phosochemically active "core" complex surrounded by discrete aggregates of the light-harvesting pigment protein. A model demonstrating the spatial relationships of photosystem I, photosystem II, and the light-harvesting complex in the chloroplast membrane is presented.

Isolation and characterization of three membranebound chlorophyll-protein complexes from four dinoflagellate species

1993 ◽  
Vol 340 (1294) ◽  
pp. 381-392 ◽  
Keyword(s):  
Energy Transfer ◽  
Photosystem I ◽  
Light Harvesting ◽  
Protein Complexes ◽  
Gradient Centrifugation ◽  
Water Soluble ◽  
Molar Ratio ◽  
Light Harvesting Complexes ◽  
Light Harvesting Complex ◽  
Isolation And Characterization

Employing discontinuous sucrose density gradient centrifugation of n -dodecyl β-d-maltoside-solubilized thylakoid membranes, three chlorophyll (Chl)-protein complexes containing Chl a , Chl c 2 and peridinin in different proportions, were isolated from the dinoflagellates Symbiodinium microadriaticum, S. kawagutii, S. pilosum and Heterocapsa pygmaea . In S. microadriaticum , the first complex, containing 13% of the total cellular Chl a , and minor quantities of Chl c 2 and peridinin, is associated with polypeptides with apparent molecular mass ( M r ) of 8-9 kDa, and demonstrated inefficient energy transfer from the accessory pigments to Chl a . The second complex contains Chl a , Chl c 2 and peridinin in a molar ratio of 1:1:2, associated with two apoproteins of M r 19-20 kDa, and comprises 45%, 75% and 70%, respectively, of the cellular Chl a , Chl c 2 and peridinin. The efficient energy transfer from Chl c 2 and peridinin to Chl a in this complex is supportive of a light-harvesting function. This Chl a - c 2 - peridin-protein complex represents the major light-harvesting complex in dinoflagellates. The third complex obtained contains 12% of the cellular Chl a , and appears to be the core of photosystem I, associated with a light-harvesting complex. This complex is spectroscopically similar to analogous preparations from different taxonomic groups, but demonstrates a unique apoprotein composition. Antibodies against the water-soluble peridinin-Chl a -protein (sPCP) light-harvesting complexes failed to cross-react with any of the thylakoid-associated complexes, as did antibodies against Chl a - c -fucoxanthin apoprotein (from diatoms). Antibodies against the P 700 apoprotein of plants did not cross-react with the photosystem I complex. Similar results were observed in the other dinoflagellates.

Sign in / Sign up

Export Citation Format

Share Document