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Mäusle SM, Agarwala N, Eichmann VG, Dau H, Nürnberg DJ, Hastings G. Nanosecond time-resolved infrared spectroscopy for the study of electron transfer in photosystem I. PHOTOSYNTHESIS RESEARCH 2024; 159:229-239. [PMID: 37420121 PMCID: PMC10991071 DOI: 10.1007/s11120-023-01035-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/05/2023] [Accepted: 06/21/2023] [Indexed: 07/09/2023]
Abstract
Microsecond time-resolved step-scan FTIR difference spectroscopy was used to study photosystem I (PSI) from Thermosynechococcus vestitus BP-1 (T. vestitus, formerly known as T. elongatus) at 77 K. In addition, photoaccumulated (P700+-P700) FTIR difference spectra were obtained at both 77 and 293 K. The FTIR difference spectra are presented here for the first time. To extend upon these FTIR studies nanosecond time-resolved infrared difference spectroscopy was also used to study PSI from T. vestitus at 296 K. Nanosecond infrared spectroscopy has never been used to study PSI samples at physiological temperatures, and here it is shown that such an approach has great value as it allows a direct probe of electron transfer down both branches in PSI. In PSI at 296 K, the infrared flash-induced absorption changes indicate electron transfer down the B- and A-branches is characterized by time constants of 33 and 364 ns, respectively, in good agreement with visible spectroscopy studies. These time constants are associated with forward electron transfer from A1- to FX on the B- and A-branches, respectively. At several infrared wavelengths flash-induced absorption changes at 296 K recover in tens to hundreds of milliseconds. The dominant decay phase is characterized by a lifetime of 128 ms. These millisecond changes are assigned to radical pair recombination reactions, with the changes being associated primarily with P700+ rereduction. This conclusion follows from the observation that the millisecond infrared spectrum is very similar to the photoaccumulated (P700+-P700) FTIR difference spectrum.
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Affiliation(s)
- Sarah M Mäusle
- Department of Physics, Freie Universität Berlin, Arnimallee 14, 14195, Berlin, Germany
| | - Neva Agarwala
- Department of Physics and Astronomy, Georgia State University, Atlanta, GA, 30303, USA
- Department of Chemistry, Georgia State University, Atlanta, GA, 30303, USA
| | - Viktor G Eichmann
- Department of Physics, Freie Universität Berlin, Arnimallee 14, 14195, Berlin, Germany
| | - Holger Dau
- Department of Physics, Freie Universität Berlin, Arnimallee 14, 14195, Berlin, Germany.
| | - Dennis J Nürnberg
- Department of Physics, Freie Universität Berlin, Arnimallee 14, 14195, Berlin, Germany.
- Dahlem Centre of Plant Sciences, Freie Universität Berlin, Berlin, Germany.
| | - Gary Hastings
- Department of Physics and Astronomy, Georgia State University, Atlanta, GA, 30303, USA.
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2
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Jha S, Maity S, Singh J, Chouhan C, Tak N, Ambatipudi K. Integrated physiological and comparative proteomics analysis of contrasting genotypes of pearl millet reveals underlying salt-responsive mechanisms. PHYSIOLOGIA PLANTARUM 2022; 174:e13605. [PMID: 34837239 DOI: 10.1111/ppl.13605] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/28/2021] [Accepted: 11/11/2021] [Indexed: 05/20/2023]
Abstract
Salinity stress poses a significant risk to plant development and agricultural yield. Therefore, elucidation of stress-response mechanisms has become essential to identify salt-tolerance genes in plants. In the present study, two genotypes of pearl millet (Pennisetum glaucum L.) with contrasting tolerance for salinity exhibited differential morpho-physiological and proteomic responses under 150 mM NaCl. The genotype IC 325825 was shown to withstand the stress better than IP 17224. The salt-tolerance potential of IC 325825 was associated with its ability to maintain intracellular osmotic, ionic, and redox homeostasis and membrane integrity under stress. The IC 325825 genotype exhibited a higher abundance of C4 photosynthesis enzymes, efficient enzymatic and non-enzymatic antioxidant system, and lower Na+ /K+ ratio compared with IP 17224. Comparative proteomics analysis revealed greater metabolic perturbation in IP 17224 under salinity, in contrast to IC 325825 that harbored pro-active stress-responsive machinery, allowing its survival and better adaptability under salt stress. The differentially abundant proteins were in silico characterized for their functions, subcellular-localization, associated pathways, and protein-protein interaction. These proteins were mainly involved in photosynthesis/response to light stimulus, carbohydrate and energy metabolism, and stress responses. Proteomics data were validated through expression profiling of the selected genes, revealing a poor correlation between protein abundance and their relative transcript levels. This study has provided novel insights into salt adaptive mechanisms in P. glaucum, demonstrating the power of proteomics-based approaches. The critical proteins identified in the present study could be further explored as potential objects for engineering stress tolerance in salt-sensitive major crops.
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Affiliation(s)
- Shweta Jha
- Plant Functional Genomics Lab, Biotechnology Unit, Department of Botany (UGC-Centre of Advanced Study), Jai Narain Vyas University, Jodhpur, Rajasthan, India
| | - Sudipa Maity
- Department of Biotechnology, Indian Institute of Technology Roorkee, Roorkee, Uttarakhand, India
| | - Jawahar Singh
- Plant Functional Genomics Lab, Biotechnology Unit, Department of Botany (UGC-Centre of Advanced Study), Jai Narain Vyas University, Jodhpur, Rajasthan, India
| | - Chaya Chouhan
- Plant Functional Genomics Lab, Biotechnology Unit, Department of Botany (UGC-Centre of Advanced Study), Jai Narain Vyas University, Jodhpur, Rajasthan, India
| | - Nisha Tak
- BNF and Microbial Genomics Lab, Department of Botany (UGC-Centre of Advanced Study), Jai Narain Vyas University, Jodhpur, Rajasthan, India
| | - Kiran Ambatipudi
- Department of Biotechnology, Indian Institute of Technology Roorkee, Roorkee, Uttarakhand, India
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Chestnut MM, Milikisiyants S, Chatterjee R, Kern J, Smirnov AI. Electronic Structure of the Primary Electron Donor P700+• in Photosystem I Studied by Multifrequency HYSCORE Spectroscopy at X- and Q-Band. J Phys Chem B 2021; 125:36-48. [PMID: 33356277 DOI: 10.1021/acs.jpcb.0c09000] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
The primary electron donor P700 of the photosystem I (PSI) is a heterodimer consisting of two chlorophyll molecules. A series of electron-transfer events immediately following the initial light excitation leads to a stabilization of the positive charge by its cation radical form, P700+•. The electronic structure of P700+• and, in particular, its asymmetry with respect to the two chlorophyll monomers is of fundamental interest and is not fully understood up to this date. Here, we apply multifrequency X- (9 GHz) and Q-band (35 GHz) hyperfine sublevel correlation (HYSCORE) spectroscopy to investigate the electron spin density distribution in the cation radical P700+• of PSI from a thermophilic cyanobacterium Thermosynechococcus elongatus. Six 14N and two 1H distinct nuclei have been resolved in the HYSCORE spectra and parameters of the corresponding nuclear hyperfine and quadrupolar hyperfine interactions were obtained by combining the analysis of HYSCORE spectral features with direct numerical simulations. Based on a close similarity of the nuclear quadrupole tensor parameters, all of the resolved 14N nuclei were assigned to six out of total eight available pyrrole ring nitrogen atoms (i.e., four in each of the chlorophylls), providing direct evidence of spin density delocalization over the both monomers in the heterodimer. Using the obtained experimental values of the 14N electron-nuclear hyperfine interaction parameters, the upper limit of the electron spin density asymmetry parameter is estimated as RA/Bupper = 7.7 ± 0.5, while a tentative assignment of 14N observed in the HYSCORE spectra yields RB/A = 3.1 ± 0.5.
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Affiliation(s)
- Melanie M Chestnut
- Department of Chemistry, North Carolina State University, 2620 Yarbrough Drive, Raleigh, North Carolina 27695-8204, United States
| | - Sergey Milikisiyants
- Department of Chemistry, North Carolina State University, 2620 Yarbrough Drive, Raleigh, North Carolina 27695-8204, United States
| | - Ruchira Chatterjee
- Molecular Biophysics and Integrated Bioimaging Division, Lawrence Berkeley National Laboratory, Berkeley, California 94720, United States
| | - Jan Kern
- Molecular Biophysics and Integrated Bioimaging Division, Lawrence Berkeley National Laboratory, Berkeley, California 94720, United States
| | - Alex I Smirnov
- Department of Chemistry, North Carolina State University, 2620 Yarbrough Drive, Raleigh, North Carolina 27695-8204, United States
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Devadasu E, Pandey J, Dhokne K, Subramanyam R. Restoration of photosynthetic activity and supercomplexes from severe iron starvation in Chlamydomonas reinhardtii. BIOCHIMICA ET BIOPHYSICA ACTA-BIOENERGETICS 2020; 1862:148331. [PMID: 33127356 DOI: 10.1016/j.bbabio.2020.148331] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Subscribe] [Scholar Register] [Received: 09/24/2020] [Accepted: 10/24/2020] [Indexed: 02/06/2023]
Abstract
The eukaryotic alga Chlamydomonas (C.) reinhardtii is used as a model organism to study photosynthetic efficiency. We studied the organization and protein profile of thylakoid membranes under severe iron (Fe2+) deficiency condition and iron supplement for their restoration. Chlorophyll (Chl) a fluorescence fast OJIP transients were decreased in the severe Fe2+ deficient cells resulting in the reduction of the photochemical efficiency. The circular dichroism (CD) results from Fe2+ deficient thylakoid membranes show a significant change in pigment-pigment and pigment-protein excitonic interactions. The organization of super-complexes was also affected significantly. Furthermore, super-complexes of photosystem (PS) II and PSI, along with its dimers, were severely reduced. The complexes separated using sucrose gradient centrifugation shows that loss of super-complexes and excitonic pigment-pigment interactions were restored in the severely Fe2+ deficient cells upon Fe supplementation for three generations. Additionally, the immunoblots demonstrated that both PSII, PSI core, and their light-harvesting complex antenna proteins were differentially decreased. However, reduced core proteins were aggregated, which in turn proteins were unfold and destabilized the supercomplexes and its function. Interestingly, the aggregated proteins were insoluble after n-Dodecyl β-D-maltoside solubilization. Further, they were identified in the pellet form. When Fe2+ was added to the severely deficient cells, the photosynthetic activity, pigment-proteins complexes, and proteins were restored to the level of control after 3rd generation.
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Affiliation(s)
- Elsinraju Devadasu
- Department of Plant Sciences, School of Life Sciences, University of Hyderabad, Hyderabad, Gachibowli, Telangana 500046, India
| | - Jayendra Pandey
- Department of Plant Sciences, School of Life Sciences, University of Hyderabad, Hyderabad, Gachibowli, Telangana 500046, India
| | - Kunal Dhokne
- Department of Plant Sciences, School of Life Sciences, University of Hyderabad, Hyderabad, Gachibowli, Telangana 500046, India
| | - Rajagopal Subramanyam
- Department of Plant Sciences, School of Life Sciences, University of Hyderabad, Hyderabad, Gachibowli, Telangana 500046, India.
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Bose J, Munns R, Shabala S, Gilliham M, Pogson B, Tyerman SD. Chloroplast function and ion regulation in plants growing on saline soils: lessons from halophytes. JOURNAL OF EXPERIMENTAL BOTANY 2017; 68:3129-3143. [PMID: 28472512 DOI: 10.1093/jxb/erx142] [Citation(s) in RCA: 107] [Impact Index Per Article: 15.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/20/2023]
Abstract
Salt stress impacts multiple aspects of plant metabolism and physiology. For instance it inhibits photosynthesis through stomatal limitation, causes excessive accumulation of sodium and chloride in chloroplasts, and disturbs chloroplast potassium homeostasis. Most research on salt stress has focused primarily on cytosolic ion homeostasis with few studies of how salt stress affects chloroplast ion homeostasis. This review asks the question whether membrane-transport processes and ionic relations are differentially regulated between glycophyte and halophyte chloroplasts and whether this contributes to the superior salt tolerance of halophytes. The available literature indicates that halophytes can overcome stomatal limitation by switching to CO2 concentrating mechanisms and increasing the number of chloroplasts per cell under saline conditions. Furthermore, salt entry into the chloroplast stroma may be critical for grana formation and photosystem II activity in halophytes but not in glycophytes. Salt also inhibits some stromal enzymes (e.g. fructose-1,6-bisphosphatase) to a lesser extent in halophyte species. Halophytes accumulate more chloride in chloroplasts than glycophytes and appear to use sodium in functional roles. We propose the molecular identities of candidate transporters that move sodium, chloride and potassium across chloroplast membranes and discuss how their operation may regulate photochemistry and photosystem I and II activity in chloroplasts.
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Affiliation(s)
- Jayakumar Bose
- Australian Research Council Centre of Excellence in Plant Energy Biology, School of Agriculture, Food and Wine, Waite Research Institute, University of Adelaide, PMB1, Glen Osmond, SA 5064, Australia
| | - Rana Munns
- Australian Research Council Centre of Excellence in Plant Energy Biology, and School of Agriculture and Environment, University of Western Australia, 35 Stirling Highway, Crawley, WA 6009, Australia
| | - Sergey Shabala
- School of Land and Food, University of Tasmania, Private Bag 54, Hobart, TAS 7001, Australia
| | - Matthew Gilliham
- Australian Research Council Centre of Excellence in Plant Energy Biology, School of Agriculture, Food and Wine, Waite Research Institute, University of Adelaide, PMB1, Glen Osmond, SA 5064, Australia
| | - Barry Pogson
- Australian Research Council Centre of Excellence in Plant Energy Biology, Research School of Biology, Australian National University, Canberra, ACT 2601, Australia
| | - Stephen D Tyerman
- Australian Research Council Centre of Excellence in Plant Energy Biology, School of Agriculture, Food and Wine, Waite Research Institute, University of Adelaide, PMB1, Glen Osmond, SA 5064, Australia
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Hasni I, Msilini N, Hamdani S, Tajmir-Riahi HA, Carpentier R. Characterization of the structural changes and photochemical activity of photosystem I under Al(3+) effect. JOURNAL OF PHOTOCHEMISTRY AND PHOTOBIOLOGY B-BIOLOGY 2015; 149:292-9. [PMID: 26123191 DOI: 10.1016/j.jphotobiol.2015.06.012] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/27/2015] [Revised: 06/08/2015] [Accepted: 06/14/2015] [Indexed: 11/27/2022]
Abstract
The photochemical activity of photosystem I (PSI) as affected by Al(3+) was investigated in thylakoid membranes and PSI submembrane fractions isolated from spinach. Biophysical and biochemical techniques such as oxygen uptake, light induced absorbance changes at 820nm, chlorophyll fluorescence emission, SDS-polyacrylamide gel electrophoresis, and FTIR spectroscopy have been used to analyze the sites and action modes of this cation on the PSI complex. Our results showed that Al(3+) above 3mM induces changes in the redox state of P700 reflected by an increase of P700 photooxidation phase and a delay of the slower rate of P700 re-reduction which reveals that Al(3+) exerted an inhibitory action at the donor side of PSI especially at plastocyanin (PC). Furthermore, results of P700 photooxidation monitored in the presence of DCMU with or without MV suggested that the same range of Al(3+) concentrations impairs the photochemical reaction centers (RC) of PSI, as shown by the decline in the amount of active population of P700, and disrupts the charge separation between P700 and the primary electron acceptor A0 leading to the inhibition of electron transfer at the acceptor side of PSI. These inhibitory actions were also accompanied by an impairment of the energy transfer from light harvesting complex (LHCI) to RC of PSI, following the disconnection of LHCI antenna as illustrated by an enhancement of chlorophyll fluorescence emission spectra at low temperature (77K). The above results coincided with FTIR measurements that indicated a conformational change of the protein secondary structures in PSI complex where 25% of α-helix was converted into β-sheet, β-antiparallel and turn structures. These structural changes in PSI complex proteins are closely related with the alteration photochemical activity of PSI including the inhibition of the electron transport through both acceptor and donor sides of PSI.
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Affiliation(s)
- Imed Hasni
- Groupe de Recherche en Biologie Végétale, Département de Chimie, Biochimie et Physique, Université du Québec à Trois-Rivières, Trois-Rivières, Qc G9A 5H7, Canada
| | - Najoua Msilini
- Laboratory of Physiology and Biochemistry of Salt Tolerance in Plants, Faculty of Sciences of Tunis, Campus University, 1060, Tunisia
| | - Saber Hamdani
- Plant Systems Biology Group, Partner Institute of Computational Biology, Chinese Academy of Sciences, Shanghai 200031, China
| | - Heidar-Ali Tajmir-Riahi
- Groupe de Recherche en Biologie Végétale, Département de Chimie, Biochimie et Physique, Université du Québec à Trois-Rivières, Trois-Rivières, Qc G9A 5H7, Canada
| | - Robert Carpentier
- Groupe de Recherche en Biologie Végétale, Département de Chimie, Biochimie et Physique, Université du Québec à Trois-Rivières, Trois-Rivières, Qc G9A 5H7, Canada.
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7
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Hastings G. Vibrational spectroscopy of photosystem I. BIOCHIMICA ET BIOPHYSICA ACTA-BIOENERGETICS 2014; 1847:55-68. [PMID: 25086273 DOI: 10.1016/j.bbabio.2014.07.014] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/29/2014] [Revised: 07/01/2014] [Accepted: 07/21/2014] [Indexed: 11/28/2022]
Abstract
Fourier transform infrared difference spectroscopy (FTIR DS) has been widely used to study the structural details of electron transfer cofactors (and their binding sites) in many types of photosynthetic protein complexes. This review focuses in particular on work that has been done to investigate the A₁cofactor in photosystem I photosynthetic reaction centers. A review of this subject area last appeared in 2006 [1], so only work undertaken since then will be covered here. Following light excitation of intact photosystem I particles the P700⁺A⁻(1) secondary radical pair state is formed within 100ps. This state decays within 300ns at room temperature, or 300μs at 77K. Given the short-lived nature of this state, it is not easily studied using "static" photo-accumulation FTIR difference techniques at either temperature. Time-resolved techniques are required. This article focuses on the use of time-resolved step-scan FTIR DS for the study of the P700⁺A⁻(1) state in intact photosystem I. Up until now, only our group has undertaken studies in this area. So, in this article, recent work undertaken in our lab is described, where we have used low-temperature (77K), microsecond time-resolved step-scan FTIR DS to study the P700⁺A⁻(1) state in photosystem I. In photosystem I a phylloquinone molecule occupies the A₁binding site. However, different quinones can be incorporated into the A1 binding site, and here work is described for photosystem I particles with plastoquinone-9, 2-phytyl naphthoquinone and 2-methyl naphthoquinone incorporated into the A₁binding site. Studies in which ¹⁸O isotope labeled phylloquinone has been incorporated into the A1 binding site are also discussed. To fully characterize PSI particles with different quinones incorporated into the A1 binding site nanosecond to millisecond visible absorption spectroscopy has been shown to be of considerable value, especially so when undertaken using identical samples under identical conditions to that used in time-resolved step-scan FTIR measurements. In this article the latest work that has been undertaken using both visible and infrared time resolved spectroscopies on the same sample will be described. Finally, vibrational spectroscopic data that has been obtained for phylloquinone in the A1 binding site in photosystem I is compared to corresponding data for ubiquinone in the QA binding site in purple bacterial reaction centers. This article is part of a Special Issue entitled: Vibrational spectroscopies and bioenergetic systems.
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Affiliation(s)
- Gary Hastings
- Department of Physics and Astronomy, Georgia State University, Atlanta, GA 30303, USA
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Liu J, Chakraborty S, Hosseinzadeh P, Yu Y, Tian S, Petrik I, Bhagi A, Lu Y. Metalloproteins containing cytochrome, iron-sulfur, or copper redox centers. Chem Rev 2014; 114:4366-469. [PMID: 24758379 PMCID: PMC4002152 DOI: 10.1021/cr400479b] [Citation(s) in RCA: 560] [Impact Index Per Article: 56.0] [Reference Citation Analysis] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/02/2013] [Indexed: 02/07/2023]
Affiliation(s)
- Jing Liu
- Department of Chemistry, Department of Biochemistry, and Center for Biophysics
and Computational
Biology, University of Illinois at Urbana-Champaign, Urbana, Illinois 61801, United States
| | - Saumen Chakraborty
- Department of Chemistry, Department of Biochemistry, and Center for Biophysics
and Computational
Biology, University of Illinois at Urbana-Champaign, Urbana, Illinois 61801, United States
| | - Parisa Hosseinzadeh
- Department of Chemistry, Department of Biochemistry, and Center for Biophysics
and Computational
Biology, University of Illinois at Urbana-Champaign, Urbana, Illinois 61801, United States
| | - Yang Yu
- Department of Chemistry, Department of Biochemistry, and Center for Biophysics
and Computational
Biology, University of Illinois at Urbana-Champaign, Urbana, Illinois 61801, United States
| | - Shiliang Tian
- Department of Chemistry, Department of Biochemistry, and Center for Biophysics
and Computational
Biology, University of Illinois at Urbana-Champaign, Urbana, Illinois 61801, United States
| | - Igor Petrik
- Department of Chemistry, Department of Biochemistry, and Center for Biophysics
and Computational
Biology, University of Illinois at Urbana-Champaign, Urbana, Illinois 61801, United States
| | - Ambika Bhagi
- Department of Chemistry, Department of Biochemistry, and Center for Biophysics
and Computational
Biology, University of Illinois at Urbana-Champaign, Urbana, Illinois 61801, United States
| | - Yi Lu
- Department of Chemistry, Department of Biochemistry, and Center for Biophysics
and Computational
Biology, University of Illinois at Urbana-Champaign, Urbana, Illinois 61801, United States
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9
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Nguyen K, Bruce BD. Growing green electricity: progress and strategies for use of photosystem I for sustainable photovoltaic energy conversion. BIOCHIMICA ET BIOPHYSICA ACTA-BIOENERGETICS 2014; 1837:1553-66. [PMID: 24388916 DOI: 10.1016/j.bbabio.2013.12.013] [Citation(s) in RCA: 70] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/22/2013] [Revised: 12/17/2013] [Accepted: 12/25/2013] [Indexed: 10/25/2022]
Abstract
Oxygenic photosynthesis is driven via sequential action of Photosystem II (PSII) and (PSI)reaction centers via the Z-scheme. Both of these pigment-membrane protein complexes are found in cyanobacteria, algae, and plants. Unlike PSII, PSI is remarkably stable and does not undergo limiting photo-damage. This stability, as well as other fundamental structural differences, makes PSI the most attractive reaction centers for applied photosynthetic applications. These applied applications exploit the efficient light harvesting and high quantum yield of PSI where the isolated PSI particles are redeployed providing electrons directly as a photocurrent or, via a coupled catalyst to yield H₂. Recent advances in molecular genetics, synthetic biology, and nanotechnology have merged to allow PSI to be integrated into a myriad of biohybrid devices. In photocurrent producing devices, PSI has been immobilized onto various electrode substrates with a continuously evolving toolkit of strategies and novel reagents. However, these innovative yet highly variable designs make it difficult to identify the rate-limiting steps and/or components that function as bottlenecks in PSI-biohybrid devices. In this study we aim to highlight these recent advances with a focus on identifying the similarities and differences in electrode surfaces, immobilization/orientation strategies, and artificial redox mediators. Collectively this work has been able to maintain an annual increase in photocurrent density (Acm⁻²) of ~10-fold over the past decade. The potential drawbacks and attractive features of some of these schemes are also discussed with their feasibility on a large-scale. As an environmentally benign and renewable resource, PSI may provide a new sustainable source of bioenergy. This article is part of a special issue entitled: photosynthesis research for sustainability: keys to produce clean energy.
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Affiliation(s)
- Khoa Nguyen
- Department of Biochemistry and Cellular and Molecular Biology, University of Tennessee, Knoxville, TN 37996, USA
| | - Barry D Bruce
- Department of Biochemistry and Cellular and Molecular Biology, University of Tennessee, Knoxville, TN 37996, USA; Department of Microbiology, University of Tennessee, Knoxville, TN 37996, USA; Bredesen Center for Interdisciplinary Research and Education, University of Tennessee, Knoxville, TN 37996, USA.
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10
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Yadavalli V, Jolley CC, Malleda C, Thangaraj B, Fromme P, Subramanyam R. Alteration of proteins and pigments influence the function of photosystem I under iron deficiency from Chlamydomonas reinhardtii. PLoS One 2012; 7:e35084. [PMID: 22514709 PMCID: PMC3325961 DOI: 10.1371/journal.pone.0035084] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/28/2011] [Accepted: 03/12/2012] [Indexed: 11/19/2022] Open
Abstract
BACKGROUND Iron is an essential micronutrient for all organisms because it is a component of enzyme cofactors that catalyze redox reactions in fundamental metabolic processes. Even though iron is abundant on earth, it is often present in the insoluble ferric [Fe (III)] state, leaving many surface environments Fe-limited. The haploid green alga Chlamydomonas reinhardtii is used as a model organism for studying eukaryotic photosynthesis. This study explores structural and functional changes in PSI-LHCI supercomplexes under Fe deficiency as the eukaryotic photosynthetic apparatus adapts to Fe deficiency. RESULTS 77K emission spectra and sucrose density gradient data show that PSI and LHCI subunits are affected under iron deficiency conditions. The visible circular dichroism (CD) spectra associated with strongly-coupled chlorophyll dimers increases in intensity. The change in CD signals of pigments originates from the modification of interactions between pigment molecules. Evidence from sucrose gradients and non-denaturing (green) gels indicates that PSI-LHCI levels were reduced after cells were grown for 72 h in Fe-deficient medium. Ultrafast fluorescence spectroscopy suggests that red-shifted pigments in the PSI-LHCI antenna were lost during Fe stress. Further, denaturing gel electrophoresis and immunoblot analysis reveals that levels of the PSI subunits PsaC and PsaD decreased, while PsaE was completely absent after Fe stress. The light harvesting complexes were also susceptible to iron deficiency, with Lhca1 and Lhca9 showing the most dramatic decreases. These changes in the number and composition of PSI-LHCI supercomplexes may be caused by reactive oxygen species, which increase under Fe deficiency conditions. CONCLUSIONS Fe deficiency induces rapid reduction of the levels of photosynthetic pigments due to a decrease in chlorophyll synthesis. Chlorophyll is important not only as a light-harvesting pigment, but also has a structural role, particularly in the pigment-rich LHCI subunits. The reduced level of chlorophyll molecules inhibits the formation of large PSI-LHCI supercomplexes, further decreasing the photosynthetic efficiency.
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Affiliation(s)
- Venkateswarlu Yadavalli
- Department of Biochemistry, School of Life Sciences, University of Hyderabad, Hyderabad, India
| | - Craig C. Jolley
- Department of Chemistry and Biochemistry, Center for Bioenergy and Photosynthesis, Arizona State University, Tempe, Arizona, United States of America
| | - Chandramouli Malleda
- Department of Biochemistry, School of Life Sciences, University of Hyderabad, Hyderabad, India
| | - Balakumar Thangaraj
- Department of Chemistry and Biochemistry, Center for Bioenergy and Photosynthesis, Arizona State University, Tempe, Arizona, United States of America
| | - Petra Fromme
- Department of Chemistry and Biochemistry, Center for Bioenergy and Photosynthesis, Arizona State University, Tempe, Arizona, United States of America
| | - Rajagopal Subramanyam
- Department of Plant Sciences, School of Life Sciences, University of Hyderabad, Hyderabad, India
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11
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Subramanyam R, Jolley C, Thangaraj B, Nellaepalli S, Webber AN, Fromme P. Structural and functional changes of PSI-LHCI supercomplexes of Chlamydomonas reinhardtii cells grown under high salt conditions. PLANTA 2010; 231:913-922. [PMID: 20183922 DOI: 10.1007/s00425-009-1097-x] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/26/2023]
Abstract
The eVect of high salt concentration (100 mM NaCl) on the organization of photosystem I-light harvesting complex I supercomplexes (PSI-LHCI) of Chlamydomonas reinhardtii was studied. The electron transfer activity was reduced by 39% in isolated PSI-LHCI supercomplexes. The visible circular dichroism (CD) spectra associated with strongly coupled chlorophyll (Chl) dimers were reduced in intensity, indicating that pigment-pigment interactions were disrupted. This data is consistent with results from Xuorescence streak camera spectroscopy, which suggest that red-shifted pigments in the PSI-LHCI antenna had been lost. Denaturing gel electrophoresis and immunoblot analysis reveals that levels of the PSI reaction center proteins PsaD, PsaE and PsaF were reduced due to salt stress. PsaE is almost completely absent under high salt conditions. It is known that the membrane-extrinsic subunits PsaD and E form the ferredoxin-docking site. Our results indicate that the PSI-LHCI supercomplex is damaged by reactive oxygen species at high salt concentration, with particular impact on the ferredoxin-docking site and the PSILHCI interface.
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Affiliation(s)
- Rajagopal Subramanyam
- Department of Biochemistry, School of Life Sciences, University of Hyderabad, Hyderabad 500046, India.
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12
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Srinivasan N, Karyagina I, Bittl R, van der Est A, Golbeck JH. Role of the Hydrogen Bond from Leu722 to the A1A Phylloquinone in Photosystem I. Biochemistry 2009; 48:3315-24. [DOI: 10.1021/bi802340s] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Nithya Srinivasan
- Department of Biochemistry and Molecular Biology, The Pennsylvania State University, University Park, Pennsylvania 16802, Institut für Experimental Physik, Fachbereich Physik, Freie Universität Berlin, Arnimallee 14, D14195 Berlin, Germany, Department of Chemistry, Brock University, 500 Glenridge Avenue, St. Catharines, ON L2S 3A1, Canada, and Department of Chemistry, The Pennsylvania State University, University Park, Pennsylvania 16802
| | - Irina Karyagina
- Department of Biochemistry and Molecular Biology, The Pennsylvania State University, University Park, Pennsylvania 16802, Institut für Experimental Physik, Fachbereich Physik, Freie Universität Berlin, Arnimallee 14, D14195 Berlin, Germany, Department of Chemistry, Brock University, 500 Glenridge Avenue, St. Catharines, ON L2S 3A1, Canada, and Department of Chemistry, The Pennsylvania State University, University Park, Pennsylvania 16802
| | - Robert Bittl
- Department of Biochemistry and Molecular Biology, The Pennsylvania State University, University Park, Pennsylvania 16802, Institut für Experimental Physik, Fachbereich Physik, Freie Universität Berlin, Arnimallee 14, D14195 Berlin, Germany, Department of Chemistry, Brock University, 500 Glenridge Avenue, St. Catharines, ON L2S 3A1, Canada, and Department of Chemistry, The Pennsylvania State University, University Park, Pennsylvania 16802
| | - Art van der Est
- Department of Biochemistry and Molecular Biology, The Pennsylvania State University, University Park, Pennsylvania 16802, Institut für Experimental Physik, Fachbereich Physik, Freie Universität Berlin, Arnimallee 14, D14195 Berlin, Germany, Department of Chemistry, Brock University, 500 Glenridge Avenue, St. Catharines, ON L2S 3A1, Canada, and Department of Chemistry, The Pennsylvania State University, University Park, Pennsylvania 16802
| | - John H. Golbeck
- Department of Biochemistry and Molecular Biology, The Pennsylvania State University, University Park, Pennsylvania 16802, Institut für Experimental Physik, Fachbereich Physik, Freie Universität Berlin, Arnimallee 14, D14195 Berlin, Germany, Department of Chemistry, Brock University, 500 Glenridge Avenue, St. Catharines, ON L2S 3A1, Canada, and Department of Chemistry, The Pennsylvania State University, University Park, Pennsylvania 16802
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Sengupta S, Majumder AL. Insight into the salt tolerance factors of a wild halophytic rice, Porteresia coarctata: a physiological and proteomic approach. PLANTA 2009; 229:911-29. [PMID: 19130079 DOI: 10.1007/s00425-008-0878-y] [Citation(s) in RCA: 93] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/04/2008] [Accepted: 12/15/2008] [Indexed: 05/02/2023]
Abstract
Salinity poses a serious threat to yield performance of cultivated rice in South Asian countries. To understand the mechanism of salt-tolerance of the wild halophytic rice, Porteresia coarctata in contrast to the salt-sensitive domesticated rice Oryza sativa, we have compared P. coarctata with the domesticated O. sativa rice varieties under salinity stress with respect to several physiological parameters and changes in leaf protein expression. P. coarctata showed a better growth performance and biomass under salinity stress. Relative water content was conserved in Porteresia during stress and sodium ion accumulation in leaves was comparatively lesser. Scanning electron microscopy revealed presence of two types of salt hairs on two leaf surfaces, each showing a different behaviour under stress. High salt stress for prolonged period also revealed accumulation of extruded NaCl crystals on leaf surface. Changes induced in leaf proteins were studied by two-dimensional gel electrophoresis and subsequent quantitative image analysis. Out of more than 700 protein spots reproducibly detected and analyzed, 60% spots showed significant changes under salinity. Many proteins showed steady patterns of up- or downregulation in response to salinity stress. Twenty protein spots were analyzed by MALDI-TOF, leading to identification of 16 proteins involved in osmolyte synthesis, photosystem functioning, RubisCO activation, cell wall synthesis and chaperone functions. We hypothesize that some of these proteins confer a physiological advantage on Porteresia under salinity, and suggest a pattern of salt tolerance strategies operative in salt-marsh grasses. In addition, such proteins may turn out to be potential targets for recombinant cloning and introgression in salt-sensitive plants.
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Affiliation(s)
- Sonali Sengupta
- Plant Molecular and Cellular Genetics, Bose Institute (Centenary Building), P-1/12, C.I.T Scheme VIIM, Kolkata, 700054, India
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14
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Jajoo A, Sahay A, Singh P, Mathur S, Zharmukhamedov SK, Klimov VV, Allakhverdiev SI, Bharti S. Elucidating the site of action of oxalate in photosynthetic electron transport chain in spinach thylakoid membranes. PHOTOSYNTHESIS RESEARCH 2008; 97:177-184. [PMID: 18563623 DOI: 10.1007/s11120-008-9314-1] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/12/2008] [Accepted: 05/19/2008] [Indexed: 05/26/2023]
Abstract
The effects of oxalate on PS II and PS I photochemistry were studied. The results suggested that in chloride-deficient thylakoid membranes, oxalate inhibited activity of PS II as well as PS I. To our knowledge, this is the only anion so far known which inhibits both the photosystems. Measurements of fluorescence induction kinetics, YZ* decay, and S2 state multiline EPR signal suggested that oxalate inhibited PS II at the donor side most likely on the oxygen evolving complex. Measurements of re-reduction of P700+ signal in isolated PS I particles in oxalate-treated samples suggested a binding site of oxalate on the donor, as well as the acceptor side of PS I.
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Affiliation(s)
- Anjana Jajoo
- School of Life Sciences, Devi Ahilya University, Vigyan Bhavan, Khandwa Road, Indore 452017, M.P., India.
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15
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Tomo T, Kato Y, Suzuki T, Akimoto S, Okubo T, Noguchi T, Hasegawa K, Tsuchiya T, Tanaka K, Fukuya M, Dohmae N, Watanabe T, Mimuro M. Characterization of highly purified photosystem I complexes from the chlorophyll d-dominated cyanobacterium Acaryochloris marina MBIC 11017. J Biol Chem 2008; 283:18198-209. [PMID: 18458090 DOI: 10.1074/jbc.m801805200] [Citation(s) in RCA: 52] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Photochemically active photosystem (PS) I complexes were purified from the chlorophyll (Chl) d-dominated cyanobacterium Acaryochloris marina MBIC 11017, and several of their properties were characterized. PS I complexes consist of 11 subunits, including PsaK1 and PsaK2; a new small subunit was identified and named Psa27. The new subunit might replace the function of PsaI that is absent in A. marina. The amounts of pigments per one molecule of Chl d' were 97.0 +/- 11.0 Chl d, 1.9 +/- 0.5 Chl a, 25.2 +/- 2.4 alpha-carotene, and two phylloquinone molecules. The light-induced Fourier transform infrared difference spectroscopy and light-induced difference absorption spectra reconfirmed that the primary electron donor of PS I (P740) was the Chl d dimer. In addition to P740, the difference spectrum contained an additional band at 728 nm. The redox potentials of P740 were estimated to be 439 mV by spectroelectrochemistry; this value was comparable with the potential of P700 in other cyanobacteria and higher plants. This suggests that the overall energetics of the PS I reaction were adjusted to the electron acceptor side to utilize the lower light energy gained by P740. The distribution of charge in P740 was estimated by a density functional theory calculation, and a partial localization of charge was predicted to P1 Chl (special pair Chl on PsaA). Based on differences in the protein matrix and optical properties of P740, construction of the PS I core in A. marina was discussed.
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Affiliation(s)
- Tatsuya Tomo
- Department of Technology and Ecology, Hall of Global Environmental Research, Kyoto University, Kyoto, Japan.
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16
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Jeanjean R, Latifi A, Matthijs HC, Havaux M. The PsaE subunit of photosystem I prevents light-induced formation of reduced oxygen species in the cyanobacterium Synechocystis sp. PCC 6803. BIOCHIMICA ET BIOPHYSICA ACTA-BIOENERGETICS 2008; 1777:308-16. [DOI: 10.1016/j.bbabio.2007.11.009] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/08/2007] [Revised: 11/28/2007] [Accepted: 11/28/2007] [Indexed: 11/25/2022]
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17
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Kantzilakis K, Aivaliotis M, Kotakis C, Krasanakis F, Rizos AK, Kotzabasis K, Tsiotis G. A comparative approach towards thylakoid membrane proteome analysis of unicellular green alga Scenedesmus obliquus. BIOCHIMICA ET BIOPHYSICA ACTA-BIOMEMBRANES 2007; 1768:2271-9. [PMID: 17574204 DOI: 10.1016/j.bbamem.2007.04.028] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/24/2007] [Revised: 04/21/2007] [Accepted: 04/24/2007] [Indexed: 12/29/2022]
Abstract
The chlorophyll (Chl)-containing membrane protein complexes from the green alga Scenedesmus obliquus have been isolated from the thylakoid membranes by solubilization with dodecyl-beta-maltoside and fractionation using a sucrose density gradient. The Chl-containing protein fractions were characterized by absorption spectroscopy, tricine SDS PAGE, BN-PAGE, and dynamic light scattering (DLS). BN-PAGE showed the presence of seven protein complexes with molecular weights in the range of 68, 118, 157, 320, 494, 828 and 955 kDa, respectively. Furthermore, light scattering reveals the simultaneous presence of particles of different sizes in the 3-4 nm and 6.0-7.5 nm range, respectively. The smaller size is related to the hydrodynamic radius of the trimer Light Harvesting Complex (LHCII), whereas the larger size is associated with the presence of photosystem I and photosystem II reaction centers. Additionally, functional information regarding protein-protein interactions was deconvoluted using coupling 2-D BN-PAGE, MALDI-TOF MS and a detailed mapping of S. obliquus photosynthetic proteome of the solubilized thylakoid membranes is therefore presented.
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Affiliation(s)
- Konstantinos Kantzilakis
- Division of Biochemistry, Department of Chemistry, University of Crete, P.O. Box 2208, 71003 Voutes Heraklion, Greece
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18
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Abstract
Oxygenic photosynthesis, the principal converter of sunlight into chemical energy on earth, is catalyzed by four multi-subunit membrane-protein complexes: photosystem I (PSI), photosystem II (PSII), the cytochrome b(6)f complex, and F-ATPase. PSI generates the most negative redox potential in nature and largely determines the global amount of enthalpy in living systems. PSII generates an oxidant whose redox potential is high enough to enable it to oxidize H(2)O, a substrate so abundant that it assures a practically unlimited electron source for life on earth. During the last century, the sophisticated techniques of spectroscopy, molecular genetics, and biochemistry were used to reveal the structure and function of the two photosystems. The new structures of PSI and PSII from cyanobacteria, algae, and plants has shed light not only on the architecture and mechanism of action of these intricate membrane complexes, but also on the evolutionary forces that shaped oxygenic photosynthesis.
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Affiliation(s)
- Nathan Nelson
- Department of Biochemistry, George S. Wise Faculty of Life Sciences, Tel Aviv University, Tel Aviv 69978, Israel.
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Affiliation(s)
- Ivano Bertini
- Magnetic Resonance Center (CERM), University of Florence, Via L. Sacconi 6, 50019 Sesto Fiorentino, Italy.
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20
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Ko BS, Babcock B, Jennings GK, Tilden SG, Peterson RR, Cliffel D, Greenbaum E. Effect of surface composition on the adsorption of photosystem I onto alkanethiolate self-assembled monolayers on gold. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2004; 20:4033-8. [PMID: 15969395 DOI: 10.1021/la0356809] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/03/2023]
Abstract
We have used self-assembled monolayers (SAMs) prepared from omega-terminated alkanethiols on gold to generate model surfaces and examine the effect of surface composition on the adsorption of Photosystem I (PSI), stabilized in aqueous solution by Triton X-100. Triton-stabilized PSI adsorbs to high-energy surfaces prepared from HO- and HO2C-terminated alkanethiols but does not adsorb to low-energy surfaces. The inhibition of PSI adsorption at low-energy surfaces is consistent with the presence of a layer of Triton X-100 that adsorbs atop the hydrophobic SAM and presents a protein-resistant poly(ethylene glycol) (PEG) surface. While the presence of the PEG surface prevents the adsorption of PSI, the displacement of the inhibiting layer of Triton X-100 by dodecanol, a more active surfactant, greatly enhances the adsorption of PSI. This inhibiting effect by Triton X-100 can be extended to other protein systems such as bovine serum albumin.
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Affiliation(s)
- B Samuel Ko
- Department of Chemical Engineering, Vanderbilt University, Nashville, Tennessee 37235, USA
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21
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Montesano M, Scheller HV, Wettstein R, Palva ET. Down-regulation of photosystem I by Erwinia carotovora-derived elicitors correlates with H(2)O(2) accumulation in chloroplasts of potato. MOLECULAR PLANT PATHOLOGY 2004; 5:115-123. [PMID: 20565588 DOI: 10.1111/j.1364-3703.2004.00213.x] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/29/2023]
Abstract
SUMMARY Identification of Solanum tuberosum genes responsive to culture filtrates (CF) from Erwinia carotovora ssp. carotovora resulted in isolation of psaD, a nuclear gene encoding the PSI-D subunit of photosystem I (PSI). This gene was rapidly and markedly down-regulated in CF-treated or wounded plants. Down-regulation of psaD transcripts was also triggered by signal molecules involved in plant defence such as methyl jasmonate. The CF-induced down-regulation of psaD transcripts was correlated with an accumulation of hydrogen peroxide in chloroplasts and a down-regulation of the NADP(+) photoreduction activity mediated by PSI. These results suggest that the CF-induced down-regulation of PSI may be related to the accumulation of reactive oxygen species in chloroplasts of plant cells responding to E. c. carotovora.
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Affiliation(s)
- Marcos Montesano
- Department of Biosciences, Division of Genetics, University of Helsinki, Box 56, FIN-00014, Helsinki, Finland
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22
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The Photosynthetic Apparatus of Chlorophyll b- and d-Containing Oxyphotobacteria. PHOTOSYNTHESIS IN ALGAE 2003. [DOI: 10.1007/978-94-007-1038-2_3] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
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23
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24
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25
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Lushy A, Verchovsky L, Nechushtai R. The stable assembly of newly synthesized PsaE into the photosystem I complex occurring via the exchange mechanism is facilitated by electrostatic interactions. Biochemistry 2002; 41:11192-9. [PMID: 12220184 DOI: 10.1021/bi025905z] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Photosystem I (PSI) is a photochemically active membrane protein complex that functions at the reducing site of the photosynthetic electron-transfer chain as plastocyanin-ferredoxin oxidoreductase. PsaE, a peripheral subunit of the PSI complex, plays an important role in the function of PSI. PsaE is involved in the docking of ferredoxin/flavodoxin to the PSI complex and also participates in the cyclic electron transfer around PSI. The molecular characterization of the assembly of newly synthesized PsaE in the thylakoid membranes or in isolated PSI complexes is the subject of the present study. For this purpose the Mastigocladus laminosus psaE gene was cloned and overexpressed in Escherichia coli, and the resulting PsaE protein was purified to homogeneity by affinity chromatography. The purified PsaE was then introduced into thylakoids isolated from M. laminosus, and the newly introduced PsaE subunit saturates the membrane. The solubilization and separation of the different thylakoid protein complexes indicated that PsaE accumulates specifically in its functional location, the PSI complex. A similar stable assembly was detected when PsaE was introduced into purified PSI complexes, i.e., in the absence of other thylakoid components. This strongly indicates that the information for the stable assembly of PsaE into PSI lies within the polypeptide itself and within other subunits of the PSI complex that interact with it. To determine the nature of these interactions, the assembly reaction was performed in conditions affecting the ionic/osmotic strength. We found that altering the ionic strength significantly affects the capability of PsaE to assemble into isolated thylakoids or PSI complexes, strongly supporting the fact that electrostatic interactions are formed between PsaE and other PSI subunits. Moreover, the data suggest that the formation of electrostatic interactions occurs concomitantly with an exchange step in which newly introduced PsaE replaces the subunit present in situ.
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Affiliation(s)
- Amit Lushy
- Department of Plant Sciences, The Silberman Institute of Life Sciences, The Hebrew University of Jerusalem, Edmond Safra Campus, Givat Ram, Jerusalem 91904, Israel
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26
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Molina-Heredia FP, Balme A, Hervás M, Navarro JA, De la Rosa MA. A comparative structural and functional analysis of cytochrome cM cytochrome c6 and plastocyanin from the cyanobacterium Synechocystis sp. PCC 6803. FEBS Lett 2002; 517:50-4. [PMID: 12062408 DOI: 10.1016/s0014-5793(02)02576-0] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
Cytochrome cM is a new c-class photosynthetic haem protein whose physiological role is still unknown. It has been proposed previously that cytochrome cM can replace cytochrome c6 and plastocyanin in transferring electrons between the two membrane complexes cytochrome b6-f and photosystem I in organisms growing under stress conditions. The experimental evidence herein provided allows us to discard such a hypothesis. We report a procedure to overexpress cytochrome cM from the cyanobacterium Synechocystis sp. PCC 6803 in Escherichia coli cells in mg quantities. This has allowed us to perform a comparative laser flash-induced kinetic analysis of photosystem I reduction by the three metalloproteins from Synechocystis. The bimolecular rate constant for the overall reaction is up to 100 times lower with cytochrome cM than with cytochrome c6 or plastocyanin. In addition, the redox potential value and surface electrostatic potential distribution of cytochrome cM are quite different from those of cytochrome c6 and plastocyanin. These findings strongly indicate that cytochrome cM cannot be recognised by and interact with the same redox partners as the other two metalloproteins.
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Affiliation(s)
- Fernando P Molina-Heredia
- Instituto de Bioquímica Vegetal y Fotosíntesis, Centro Isla de la Cartuja, Universidad de Sevilla y CSIC, Américo Vespucio s/n, Sevilla, Spain
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27
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Abstract
Ferredoxin and flavodoxin are soluble proteins which are reduced by the terminal electron acceptors of photosystem I. The kinetics of ferredoxin (flavodoxin) photoreduction are discussed in detail, together with the last steps of intramolecular photosystem I electron transfer which precede ferredoxin (flavodoxin) reduction. The present knowledge concerning the photosystem I docking site for ferredoxin and flavodoxin is described in the second part of the review.
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Affiliation(s)
- P Sétif
- Section de Bioénergétique and CNRS URA 2096, Département de Biologie Cellulaire et Moléculaire, CEA Saclay, 91191, Gif sur Yvette, France.
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28
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Abstract
In plants and cyanobacteria, the primary step in oxygenic photosynthesis, the light induced charge separation, is driven by two large membrane intrinsic protein complexes, the photosystems I and II. Photosystem I catalyses the light driven electron transfer from plastocyanin/cytochrome c(6) on the lumenal side of the membrane to ferredoxin/flavodoxin at the stromal side by a chain of electron carriers. Photosystem I of Synechococcus elongatus consists of 12 protein subunits, 96 chlorophyll a molecules, 22 carotenoids, three [4Fe4S] clusters and two phylloquinones. Furthermore, it has been discovered that four lipids are intrinsic components of photosystem I. Photosystem I exists as a trimer in the native membrane with a molecular mass of 1068 kDa for the whole complex. The X-ray structure of photosystem I at a resolution of 2.5 A shows the location of the individual subunits and cofactors and provides new information on the protein-cofactor interactions. [P. Jordan, P. Fromme, H.T. Witt, O. Klukas, W. Saenger, N. Krauss, Nature 411 (2001) 909-917]. In this review, biochemical data and results of biophysical investigations are discussed with respect to the X-ray crystallographic structure in order to give an overview of the structure and function of this large membrane protein.
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Affiliation(s)
- P Fromme
- Max Volmer Laboratorium für Biophysikalische Chemie Institut für Chemie, Technische Universität Berlin, Germany.
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Navarro JA, Myshkin E, De la Rosa MA, Bullerjahn GS, Hervás M. The unique proline of the Prochlorothrix hollandica plastocyanin hydrophobic patch impairs electron transfer to photosystem I. J Biol Chem 2001; 276:37501-5. [PMID: 11457853 DOI: 10.1074/jbc.m105367200] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
A number of surface residues of plastocyanin from Prochlorothrix hollandica have been modified by site-directed mutagenesis. Changes have been made in amino acids located in the amino-terminal hydrophobic patch of the copper protein, which presents a variant structure as compared with other plastocyanins. The single mutants Y12G, Y12F, Y12W, P14L, and double mutant Y12G/P14L have been produced. Their reactivity toward photosystem I has been analyzed by laser flash absorption spectroscopy. Plots of the observed rate constant with all mutants versus plastocyanin concentration show a saturation profile similar to that with wild-type plastocyanin, thus suggesting the formation of a plastocyanin-photosystem I transient complex. The mutations do not induce relevant changes in the equilibrium constant for complex formation but induce significant variations in the electron transfer rate constant, mainly with the two mutants at proline 14. Additionally, molecular dynamics calculations indicate that mutations at position 14 yield small changes in the geometry of the copper center. The comparative kinetic analysis of the reactivity of plastocyanin mutants toward photosystem I from different organisms (plants and cyanobacteria) reveals that reversion of the unique proline of Prochlorothrix plastocyanin to the conserved leucine of all other plastocyanins at this position enhances the reactivity of the Prochlorothrix protein.
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Affiliation(s)
- J A Navarro
- Instituto de Bioquimica Vegetal y Fotosintesis, Centro de Investigaciones Cientificas Isla de la Cartuja, Universidad de Sevilla, Spain
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30
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Chitnis PR. PHOTOSYSTEM I: Function and Physiology. ANNUAL REVIEW OF PLANT PHYSIOLOGY AND PLANT MOLECULAR BIOLOGY 2001; 52:593-626. [PMID: 11337410 DOI: 10.1146/annurev.arplant.52.1.593] [Citation(s) in RCA: 143] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
Photosystem I is the light-driven plastocyanin-ferredoxin oxidoreductase in the thylakoid membranes of cyanobacteria and chloroplasts. In recent years, sophisticated spectroscopy, molecular genetics, and biochemistry have been used to understand the light conversion and electron transport functions of photosystem I. The light-harvesting complexes and internal antenna of photosystem I absorb photons and transfer the excitation energy to P700, the primary electron donor. The subsequent charge separation and electron transport leads to the reduction of ferredoxin. The photosystem I proteins are responsible for the precise arrangement of cofactors and determine redox properties of the electron transfer centers. With the availability of genomic information and the structure of photosystem I, one can now probe the functions of photosystem I proteins and cofactors. The strong reductant produced by photosystem I has a central role in chloroplast metabolism, and thus photosystem I has a critical role in the metabolic networks and physiological responses in plants.
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Affiliation(s)
- Parag R Chitnis
- Department of Biochemistry, Biophysics, and Molecular Biology, Iowa State University, Ames, Iowa 50011; e-mail:
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31
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Nakamura A, Tanaka S, Watanabe T. Normal-phase HPLC separation of possible biosynthetic intermediates of pheophytin a and chlorophyll a'. ANAL SCI 2001; 17:509-13. [PMID: 11990567 DOI: 10.2116/analsci.17.509] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Abstract
Normal-phase HPLC conditions have been developed for separating the C17(3) isoprenoid isomers, which are expected to be formed as biosynthetic intermediates of chlorophyll (Chl) a, Chl a' (C13(2)-epimer of Chl a), pheophytin (Pheo) a and protochlorophyll (PChl). The application of these conditions to pigment composition analysis of greening etiolated barley leaves allowed us to detect, for the first time, the C17(3) isomers of Chl a', a possible constituent of the primary electron donor of photosystem (PS) I, P700, and those of Pheo a, the primary electron acceptor of PS II, in the very early stage of greening. The C17(3) isomer distribution patterns were approximately the same between Chl a and Chl a', but significantly different between Pheo a and Chl a', probably reflecting the similarity and difference, respectively, in the biosynthetic pathways of these pigment pairs.
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Affiliation(s)
- A Nakamura
- Institute of Industrial Science, The University of Tokyo, Komaba, Meguro, Japan.
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32
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Käss H, Fromme P, Witt HT, Lubitz W. Orientation and Electronic Structure of the Primary Donor Radical Cation in Photosystem I: A Single Crystals EPR and ENDOR Study. J Phys Chem B 2001. [DOI: 10.1021/jp0032311] [Citation(s) in RCA: 88] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Hanno Käss
- Max-Volmer-Institut für Biophysikalische Chemie und Biochemie, Technische Universität Berlin, Str. d. 17. Juni 135, D-10623 Berlin, Germany
| | - Petra Fromme
- Max-Volmer-Institut für Biophysikalische Chemie und Biochemie, Technische Universität Berlin, Str. d. 17. Juni 135, D-10623 Berlin, Germany
| | - Horst T. Witt
- Max-Volmer-Institut für Biophysikalische Chemie und Biochemie, Technische Universität Berlin, Str. d. 17. Juni 135, D-10623 Berlin, Germany
| | - Wolfgang Lubitz
- Max-Volmer-Institut für Biophysikalische Chemie und Biochemie, Technische Universität Berlin, Str. d. 17. Juni 135, D-10623 Berlin, Germany
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Zolla L, Timperio AM. High performance liquid chromatography-electrospray mass spectrometry for the simultaneous resolution and identification of intrinsic thylakoid membrane proteins. Proteins 2000; 41:398-406. [PMID: 11025550 DOI: 10.1002/1097-0134(20001115)41:3<398::aid-prot110>3.0.co;2-k] [Citation(s) in RCA: 20] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
Abstract
In higher plants, both photosystem I (PSI) and II (PSII) consist of membrane-embedded proteins that contain more than one transmembrane alpha helix. PSI is a multiprotein complex consisting of a core complex of thirteen proteins surrounded by four different types of light harvesting antenna proteins. Up to now, the protein components of both photosystems have been characterized by SDS-PAGE and/or immunoblotting and, therefore, identification made only on the basis of electrophoretic mobility, which is sometimes not sufficient to discriminate between individual membrane proteins. This is also complicated by the fact that some proteins, such as the antenna proteins, have almost identical molecular mass and amino acid sequence, making it difficult to identify and ascertain the relative stoichiometry of the proteins. In this paper, we report the complete resolution of the antenna proteins and most of the core components of PSI from spinach, together with the identification of proteins by molecular mass, successfully deduced by the combined use of HPLC coupled on-line with a mass spectrometer equipped with an electrospray ion source (ESI-MS). The proposed RP-HPLC-ESI-MS method holds several advantages over SDS-PAGE, including better protein separation, especially for antenna proteins, mass accuracy, speed, efficiency, and the potential to reveal isomeric forms. Moreover, the molecular masses determined by HPLC-ESI-MS are in good agreement with the molecular masses of the individual components calculated on the basis of their nucleotide-derived amino acid sequences, indicating an absence of post-translational modifications in these proteins. It follows that if the method proposed is useful for these highly hydrophobic proteins, it may be of general use for any membrane proteins, where the presence of detergent for solubilization may compromise their characterization.
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Affiliation(s)
- L Zolla
- Dipartimento di Scienze Ambientali, Università della Tuscia, Viterbo, Italy.
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Mann NH, Novac N, Mullineaux CW, Newman J, Bailey S, Robinson C. Involvement of an FtsH homologue in the assembly of functional photosystem I in the cyanobacterium Synechocystis sp. PCC 6803. FEBS Lett 2000; 479:72-7. [PMID: 10940391 DOI: 10.1016/s0014-5793(00)01871-8] [Citation(s) in RCA: 80] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
The Synechocystis sp. PCC 6803 genome encodes four putative homologues of the AAA protease FtsH, two of which (slr0228 and sll1463) have been subjected to insertional mutagenesis in this study. Disruption of sll1463 had no discernible effect but disruption of slr0228 caused a 60% reduction in the abundance of functional photosystem I, without affecting the cellular content of photosystem II or phycobilisomes. Fluorescence and immunoblotting analyses show reductions in PS I polypeptides and possible structural alterations in the residual PS I, indicating an important role for slr0228 in PS I biogenesis.
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Affiliation(s)
- N H Mann
- Department of Biological Sciences, University of Warwick, Coventry, UK.
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35
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Hope AB. Electron transfers amongst cytochrome f, plastocyanin and photosystem I: kinetics and mechanisms. BIOCHIMICA ET BIOPHYSICA ACTA 2000; 1456:5-26. [PMID: 10611452 DOI: 10.1016/s0005-2728(99)00101-2] [Citation(s) in RCA: 166] [Impact Index Per Article: 6.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
The review covers the theory and practice of the determination of kinetic constants for the electron transfer reactions in chloroplast thylakoid membranes between plastocyanin and cytochrome f in cytochrome bf complexes, and between plastocyanin and the reaction centre of photosystem I. Effects of ionic strength and pH are featured. The contribution of mutant studies is included. It is concluded that nearly all data from in vitro experiments can be interpreted with a reaction scheme in which an encounter complex between donor and acceptor is formed by long-range electrostatic attraction, followed by rearrangement during which metal centres become close enough for rapid intra-complex electron transfer. In vivo experiments so far cast doubt on this particular sequence, but their interpretation is not straightforward. Means of modelling the bimolecular complex between cytochrome f and plastocyanin are outlined, and two likely structures are illustrated. The complex formed by plastocyanin and photosystem I in higher plants involves the PsaF subunit, but its structure has not been fully determined.
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Affiliation(s)
- A B Hope
- School of Biological Sciences, Faculty of Science and Engineering, Flinders University, GPO Box 2100, Adelaide, SA, Australia.
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36
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Molina-Heredia FP, Díaz-Quintana A, Hervás M, Navarro JA, De La Rosa MA. Site-directed mutagenesis of cytochrome c(6) from Anabaena species PCC 7119. Identification of surface residues of the hemeprotein involved in photosystem I reduction. J Biol Chem 1999; 274:33565-70. [PMID: 10559243 DOI: 10.1074/jbc.274.47.33565] [Citation(s) in RCA: 36] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
A number of surface residues of cytochrome c(6) from the cyanobacterium Anabaena sp. PCC 7119 have been modified by site-directed mutagenesis. Changes were made in six amino acids, two near the heme group (Val-25 and Lys-29) and four in the positively charged patch (Lys-62, Arg-64, Lys-66, and Asp-72). The reactivity of mutants toward the membrane-anchored complex photosystem I was analyzed by laser flash absorption spectroscopy. The experimental results indicate that cytochrome c(6) possesses two areas involved in the redox interaction with photosystem I: 1) a positively charged patch that may drive its electrostatic attractive movement toward photosystem I to form a transient complex and 2) a hydrophobic region at the edge of the heme pocket that may provide the contact surface for the transfer of electrons to P(700). The isofunctionality of these two areas with those found in plastocyanin (which acts as an alternative electron carrier playing the same role as cytochrome c(6)) are evident.
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Affiliation(s)
- F P Molina-Heredia
- Instituto de Bioquímica Vegetal y Fotosíntesis, Universidad de Sevilla y Consejo Superior de Investigaciones Científicas, Centro Isla de la Cartuja, Américo Vespucio s/n, 41092 Sevilla, Spain
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37
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Karapetyan NV, Holzwarth AR, Rögner M. The photosystem I trimer of cyanobacteria: molecular organization, excitation dynamics and physiological significance. FEBS Lett 1999; 460:395-400. [PMID: 10556505 DOI: 10.1016/s0014-5793(99)01352-6] [Citation(s) in RCA: 107] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
The photosystem I complex organized in cyanobacterial membranes preferentially in trimeric form participates in electron transport and is also involved in dissipation of excess energy thus protecting the complex against photodamage. A small number of longwave chlorophylls in the core antenna of photosystem I are not located in the close vicinity of P700, but at the periphery, and increase the absorption cross-section substantially. The picosecond fluorescence kinetics of trimers resolved the fastest energy transfer components reflecting the equilibration processes in the core antenna at different redox states of P700. Excitation kinetics in the photosystem I bulk antenna is nearly trap-limited, whereas excitation trapping from longwave chlorophyll pools is diffusion-limited and occurs via the bulk antenna. Charge separation in the photosystem I reaction center is the fastest of all known reaction centers.
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Affiliation(s)
- N V Karapetyan
- A.N. Bakh Institute of Biochemistry, Russian Academy of Sciences, 117071, Moscow, Russia.
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38
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Horiuchi H, Yokawa A, Okutsu T, Hiratsuka H. Laser Flash Photolysis Studies of the Photo-Ring-Opening Reaction of Flav-3-en-2-ol. BULLETIN OF THE CHEMICAL SOCIETY OF JAPAN 1999. [DOI: 10.1246/bcsj.72.2429] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
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Sun J, Xu W, Hervás M, Navarro JA, Rosa MA, Chitnis PR. Oxidizing side of the cyanobacterial photosystem I. Evidence for interaction between the electron donor proteins and a luminal surface helix of the PsaB subunit. J Biol Chem 1999; 274:19048-54. [PMID: 10383406 DOI: 10.1074/jbc.274.27.19048] [Citation(s) in RCA: 34] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Photosystem I (PSI) interacts with plastocyanin or cytochrome c6 on the luminal side. To identify sites of interaction between plastocyanin/cytochrome c6 and the PSI core, site-directed mutations were generated in the luminal J loop of the PsaB protein from Synechocystis sp. PCC 6803. The eight mutant strains differed in their photoautotrophic growth. Western blotting with subunit-specific antibodies indicated that the mutations affected the PSI level in the thylakoid membranes. PSI proteins could not be detected in the S600R/G601C/N602I, N609K/S610C/T611I, and M614I/G615C/W616A mutant membranes. The other mutant strains contained different levels of PSI proteins. Among the mutant strains that contained PSI proteins, the H595C/L596I, Q627H/L628C/I629S, and N638C/N639S mutants showed similar levels of PSI-mediated electron transfer activity when either cytochrome c6 or an artificial electron donor was used. In contrast, cytochrome c6 could not function as an electron donor to the W622C/A623R mutant, even though the PSI activity mediated by an artificial electron donor was detected in this mutant. Thus, the W622C/A623R mutation affected the interaction of the PSI complex with cytochrome c6. Biotin-maleimide modification of the mutant PSI complexes indicated that His-595, Trp-622, Leu-628, Tyr-632, and Asn-638 in wild-type PsaB may be exposed on the surface of the PSI complex. The results presented here demonstrate the role of an extramembrane loop of a PSI core protein in the interaction with soluble electron donor proteins.
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Affiliation(s)
- J Sun
- Department of Biochemistry and Biophysics, Iowa State University, Ames, Iowa 50011, USA
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40
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Kruip J, Karapetyan NV, Terekhova IV, Rögner M. In vitro oligomerization of a membrane protein complex. liposome-based reconstitution of trimeric photosystem I from isolated monomers. J Biol Chem 1999; 274:18181-8. [PMID: 10373417 DOI: 10.1074/jbc.274.26.18181] [Citation(s) in RCA: 58] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Many membrane proteins can be isolated in different oligomeric forms. Photosystem I (PSI), for example, exists in cyanobacteria either as a monomeric or as a trimeric complex. Neither the factors responsible for the specific trimerization process nor its biological role are known at present. In the filamentous cyanobacterium Spirulina platensis, trimers in contrast to monomers show chlorophyll fluorescence emission at 760 nm. To investigate the oligomerization process as well as the nature of the long wavelength chlorophylls, we describe here an in vitro reconstitution procedure to assemble trimeric PS I from isolated purified PS I monomers. Monomers (and trimers) were extracted from S. platensis with n-dodecyl beta-D-maltoside and further purified by perfusion chromatography steps. The isolated complexes had the same polypeptide composition as other cyanobacteria (PsaA-PsaF and PsaI-PsaM), as determined from high resolution gels and immunoblotting. They were incorporated into proteoliposomes, which had been prepared by the detergent absorption method, starting from a phosphatidylcholine:phosphatidic acid mixture solubilized by octylglucoside. After the addition of monomeric PS I (lipid:chlorophyll, 25:1), octylglucoside was gradually removed by the stepwise addition of Biobeads. The 77 K fluorescence emission spectrum of these proteoliposomes displays a long wavelength emission at 760 nm that is characteristic of PS I trimers, which indicates for the first time the successful in vitro reconstitution of PS I trimers. In addition, a high performance liquid chromatography analysis of complexes extracted from these proteoliposomes confirms the formation of structural trimers. We also could show with this system 1) that at least one of the stromal subunits PsaC, -D, and -E is necessary for trimer formation and 2) that the extreme long wavelength emitting chlorophyll is formed as a result of trimer formation.
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Affiliation(s)
- J Kruip
- Faculty of Biology, Plant Biochemistry, Ruhr-University Bochum, D-44780 Bochum, Germany
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41
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Klukas O, Schubert WD, Jordan P, Krauss N, Fromme P, Witt HT, Saenger W. Photosystem I, an improved model of the stromal subunits PsaC, PsaD, and PsaE. J Biol Chem 1999; 274:7351-60. [PMID: 10066799 DOI: 10.1074/jbc.274.11.7351] [Citation(s) in RCA: 73] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
An improved electron density map of photosystem I (PSI) calculated at 4-A resolution yields a more detailed structural model of the stromal subunits PsaC, PsaD, and PsaE than previously reported. The NMR structure of the subunit PsaE of PSI from Synechococcus sp. PCC7002 (Falzone, C. J., Kao, Y.-H., Zhao, J., Bryant, D. A., and Lecomte, J. T. J. (1994) Biochemistry 33, 6052-6062) has been used as a model to interpret the region of the electron density map corresponding to this subunit. The spatial orientation with respect to other subunits is described as well as the possible interactions between the stromal subunits. A first model of PsaD consisting of a four-stranded beta-sheet and an alpha-helix is suggested, indicating that this subunit partly shields PsaC from the stromal side. In addition to the improvements on the stromal subunits, the structural model of the membrane-integral region of PSI is also extended. The current electron density map allows the identification of the N and C termini of the subunits PsaA and PsaB. The 11-transmembrane alpha-helices of these subunits can now be assigned uniquely to the hydrophobic segments identified by hydrophobicity analyses.
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Affiliation(s)
- O Klukas
- Institut für Kristallographie, Freie Universität Berlin, Takustrassett 6, D-14195 Berlin, Germany
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42
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Bertini I, Ciurli S, Dikiy A, Gasanov R, Luchinat C, Martini G, Safarov N. High-Field NMR Studies of Oxidized Blue Copper Proteins: The Case of Spinach Plastocyanin. J Am Chem Soc 1999. [DOI: 10.1021/ja983833m] [Citation(s) in RCA: 89] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Ivano Bertini
- Contribution from the Department of Chemistry, University of Florence, Via Gino Capponi 7/9, 50121 Florence, Italy, Institute of Agricultural Chemistry, University of Bologna, viale Berti Pichat 10, 40120 Bologna, Italy, Institute of Molecular Biology and Biotechnology, Azerbaijan Academy of Sciences, Matbuat pr., 2, 370073, Baku, Azerbaijan, and Department of Soil Science and Plant Nutrition, University of Florence, P.le delle Cascine 28, 50144 Florence, Italy
| | - Stefano Ciurli
- Contribution from the Department of Chemistry, University of Florence, Via Gino Capponi 7/9, 50121 Florence, Italy, Institute of Agricultural Chemistry, University of Bologna, viale Berti Pichat 10, 40120 Bologna, Italy, Institute of Molecular Biology and Biotechnology, Azerbaijan Academy of Sciences, Matbuat pr., 2, 370073, Baku, Azerbaijan, and Department of Soil Science and Plant Nutrition, University of Florence, P.le delle Cascine 28, 50144 Florence, Italy
| | - Alexander Dikiy
- Contribution from the Department of Chemistry, University of Florence, Via Gino Capponi 7/9, 50121 Florence, Italy, Institute of Agricultural Chemistry, University of Bologna, viale Berti Pichat 10, 40120 Bologna, Italy, Institute of Molecular Biology and Biotechnology, Azerbaijan Academy of Sciences, Matbuat pr., 2, 370073, Baku, Azerbaijan, and Department of Soil Science and Plant Nutrition, University of Florence, P.le delle Cascine 28, 50144 Florence, Italy
| | - Ralphreed Gasanov
- Contribution from the Department of Chemistry, University of Florence, Via Gino Capponi 7/9, 50121 Florence, Italy, Institute of Agricultural Chemistry, University of Bologna, viale Berti Pichat 10, 40120 Bologna, Italy, Institute of Molecular Biology and Biotechnology, Azerbaijan Academy of Sciences, Matbuat pr., 2, 370073, Baku, Azerbaijan, and Department of Soil Science and Plant Nutrition, University of Florence, P.le delle Cascine 28, 50144 Florence, Italy
| | - Claudio Luchinat
- Contribution from the Department of Chemistry, University of Florence, Via Gino Capponi 7/9, 50121 Florence, Italy, Institute of Agricultural Chemistry, University of Bologna, viale Berti Pichat 10, 40120 Bologna, Italy, Institute of Molecular Biology and Biotechnology, Azerbaijan Academy of Sciences, Matbuat pr., 2, 370073, Baku, Azerbaijan, and Department of Soil Science and Plant Nutrition, University of Florence, P.le delle Cascine 28, 50144 Florence, Italy
| | - Giacomo Martini
- Contribution from the Department of Chemistry, University of Florence, Via Gino Capponi 7/9, 50121 Florence, Italy, Institute of Agricultural Chemistry, University of Bologna, viale Berti Pichat 10, 40120 Bologna, Italy, Institute of Molecular Biology and Biotechnology, Azerbaijan Academy of Sciences, Matbuat pr., 2, 370073, Baku, Azerbaijan, and Department of Soil Science and Plant Nutrition, University of Florence, P.le delle Cascine 28, 50144 Florence, Italy
| | - Niaz Safarov
- Contribution from the Department of Chemistry, University of Florence, Via Gino Capponi 7/9, 50121 Florence, Italy, Institute of Agricultural Chemistry, University of Bologna, viale Berti Pichat 10, 40120 Bologna, Italy, Institute of Molecular Biology and Biotechnology, Azerbaijan Academy of Sciences, Matbuat pr., 2, 370073, Baku, Azerbaijan, and Department of Soil Science and Plant Nutrition, University of Florence, P.le delle Cascine 28, 50144 Florence, Italy
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Jin P, Sun J, Chitnis PR. Structural features and assembly of the soluble overexpressed PsaD subunit of photosystem I. BIOCHIMICA ET BIOPHYSICA ACTA 1999; 1410:7-18. [PMID: 10076011 DOI: 10.1016/s0005-2728(98)00169-8] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
Abstract
PsaD is a peripheral protein on the reducing side of photosystem I (PS I). We expressed the psaD gene from the thermophilic cyanobacterium Mastigocladus laminosus in Escherichia coli and obtained a soluble protein with a polyhistidine tag at the carboxyl terminus. The soluble PsaD protein was purified by Ni-affinity chromatography and had a mass of 16716 Da by MALDI-TOF. The N-terminal amino acid sequence of the overexpressed PsaD matched the N-terminal sequence of the native PsaD from M. laminosus. The soluble PsaD could assemble into the PsaD-less PS I. As determined by isothermal titration calorimetry, PsaD bound to PS I with 1.0 binding site per PS I, the binding constant of 7.7x10(6) M-1, and the enthalpy change of -93.6 kJ mol-1. This is the first time that the binding constant and binding heat have been determined in the assembly of any photosynthetic membrane protein. To identify the surface-exposed domains, purified PS I complexes and overexpressed PsaD were treated with N-hydroxysuccinimidobiotin (NHS-biotin) and biotin-maleimide, and the biotinylated residues were mapped. The Cys66, Lys21, Arg118 and Arg119 residues were exposed on the surface of soluble PsaD whereas the Lys129 and Lys131 residues were not exposed on the surface. Consistent with the X-ray crystallographic studies on PS I, circular dichroism spectroscopy revealed that PsaD contains a small proportion of alpha-helical conformation.
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Affiliation(s)
- P Jin
- Department of Biochemistry and Biophysics, Iowa State University, 4156 Molecular Biology Building, Ames, IA 50011, USA
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44
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Sticht H, Rösch P. The structure of iron-sulfur proteins. PROGRESS IN BIOPHYSICS AND MOLECULAR BIOLOGY 1998; 70:95-136. [PMID: 9785959 DOI: 10.1016/s0079-6107(98)00027-3] [Citation(s) in RCA: 114] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
Ferredoxins are a group of iron-sulfur proteins for which a wealth of structural and mutational data have recently become available. Previously unknown structures of ferredoxins which are adapted to halophilic, acidophilic or hyperthermophilic environments and new cysteine patterns for cluster ligation and non-cysteine cluster ligation have been described. Site-directed mutagenesis experiments have given insight into factors that influence the geometry, stability, redox potential, electronic properties and electron-transfer reactivity of iron-sulfur clusters.
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Affiliation(s)
- H Sticht
- Lehrstuhl für Struktur und Chemie der Biopolymere, Universität Bayreuth, Germany.
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45
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Sun J, Ke A, Jin P, Chitnis VP, Chitnis PR. Isolation and functional study of photosystem I subunits in the cyanobacterium Synechocystis sp. PCC 6803. Methods Enzymol 1998; 297:124-39. [PMID: 9750206 DOI: 10.1016/s0076-6879(98)97010-0] [Citation(s) in RCA: 39] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/08/2023]
Affiliation(s)
- J Sun
- Department of Biochemistry and Biophysics, Iowa State University, Ames 50011, USA
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46
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Naver H, Scott MP, Golbeck JH, Olsen CE, Scheller HV. The eight-amino acid internal loop of PSI-C mediates association of low molecular mass iron-sulfur proteins with the P700-FX core in photosystem I. J Biol Chem 1998; 273:18778-83. [PMID: 9668051 DOI: 10.1074/jbc.273.30.18778] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
The PSI-C subunit of photosystem I (PS I) shows similarity to soluble 2[4Fe-4S] ferredoxins. PSI-C contains an eight residue internal loop and a 15 residue C-terminal extension which are absent in the ferredoxins. The eight-residue loop has been shown to interact with PSI-A/PSI-B (Naver, H., Scott, M. P., Golbeck, J. H., Moller, B. L., and Scheller, H. V. (1996) J. Biol. Chem. 271, 8996-9001). Four mutant proteins were constructed. Two were modified barley PSI-C proteins, one lacking the loop and the C terminus (PSI-Ccore) and one where the loop replace the C-terminal extension (PSI-CcoreLc-term). Two were modified Clostridium pasteurianum ferredoxins, one with the loop of barley PSI-C and one with both the loop and the C terminus of PSI-C. Wild-type proteins and the mutants were used to reconstitute barley P700-FX cores lacking PSI-C, -D, and-E. Western blotting showed that PSI-CcoreLc-term binds to PS I, whereas PSI-Ccore does not. Without PSI-D the PSI-CcoreLc-term mutant accepts electrons from FX in contrast to PSI-C mutants without the loop. Flash photolysis of P700-FX cores reconstituted with C. pasteurianum ferredoxin showed that only the ferredoxin mutants with the loop accepted electrons from FX. From this, it is concluded that the loop of PSI-C is necessary and sufficient for the association between PS I and PSI-C, and that the loop is functional as an interaction domain even when positioned at the C terminus of PSI-C or on a low molecular mass, soluble ferredoxin.
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Affiliation(s)
- H Naver
- Plant Biochemistry Laboratory, Department of Plant Biology, The Royal Veterinary and Agricultural University, 40 Thorvaldsensvej, DK 1871 Frederiksberg C, Copenhagen, Denmark
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47
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Fromme P, Witt HT. Improved isolation and crystallization of photosystem I for structural analysis. BIOCHIMICA ET BIOPHYSICA ACTA-BIOENERGETICS 1998. [DOI: 10.1016/s0005-2728(98)00059-0] [Citation(s) in RCA: 109] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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Nakamura A, Watanabe T. HPLC determination of photosynthetic pigments during greening of etiolated barley leaves. Evidence for the biosynthesis of chlorophyll a'. FEBS Lett 1998; 426:201-4. [PMID: 9599008 DOI: 10.1016/s0014-5793(98)00344-5] [Citation(s) in RCA: 22] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
The temporal evolution of pigment composition during greening of etiolated barley leaves was investigated by reversed-phase HPLC with particular attention to chlorophyll (Chl) a' (C13(2) epimer of Chl a), which had been detected by ourselves in photosystem (PS) I particles. At early stages of greening, the Chl a'/Chl a molar ratio rapidly increased to a level more than twice that in mature leaves, then gradually leveled off, accompanied by a growth of the Chl b/Chl a ratio, to the mature level. After 3 h of illumination, the temporal evolution of the Chl a'/Chl a molar ratio nearly paralleled that of the P700/Chl a ratio with a stoichiometry Chl a'/P700 approximately equal to 2: this strongly suggests that Chl a' is biosynthesized as a constituent of the PS I reaction center complex.
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Affiliation(s)
- A Nakamura
- Institute of Industrial Science, University of Tokyo, Japan.
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49
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Vassiliev IR, Jung YS, Yang F, Golbeck JH. PsaC subunit of photosystem I is oriented with iron-sulfur cluster F(B) as the immediate electron donor to ferredoxin and flavodoxin. Biophys J 1998; 74:2029-35. [PMID: 9545061 PMCID: PMC1299543 DOI: 10.1016/s0006-3495(98)77909-3] [Citation(s) in RCA: 52] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023] Open
Abstract
The PsaC subunit of photosystem I (PS I) binds two [4Fe-4S] clusters, F(A) and F(B), functioning as electron carriers between F(X) and soluble ferredoxin. To resolve the issue whether F(A) or F(B) is proximal to F(X), we used single-turnover flashes to promote step-by-step electron transfer between electron carriers in control (both F(A) and F(B) present) and HgCl2-treated (F(B)-less) PS I complexes from Synechococcus sp. PCC 6301 and analyzed the kinetics of P700+ reduction by monitoring the absorbance changes at 832 nm in the presence of a fast electron donor (phenazine methosulfate (PMS)). In control PS I complexes exogenously added ferredoxin, or flavodoxin could be photoreduced on each flash, thus allowing P700+ to be reduced from PMS. In F(B)-less complexes, both in the presence and in the absence of ferredoxin or flavodoxin, P700+ was reduced from PMS only on the first flash and was reduced from F(X)- on the following flashes, indicating lack of electron transfer to ferredoxin or flavodoxin. In the F(B)-less complexes, a normal level of P700 photooxidation was detected accompanied by a high yield of charge recombination between P700+ and F(A)- in the presence of a slow donor, 2,6-dichlorophenol-indophenol. This recombination remained the only pathway of F(A)- reoxidation in the presence of added ferredoxin, consistent with the lack of forward electron transfer. F(A)- could be reoxidized by methyl viologen in F(B)-less PS I complexes, although at a concentration two orders of magnitude higher than is required in wild-type PS I complexes, thus implying the presence of a diffusion barrier. The inhibition of electron transfer to ferredoxin and flavodoxin was completely reversed after reconstituting the F(B) cluster. Using rate versus distance estimates for electron transfer rates from F(X) to ferredoxin for two possible orientations of PsaC, we conclude that the kinetic data are best compatible with PsaC being oriented with F(A) as the cluster proximal to F(X) and F(B) as the distal cluster that donates electrons to ferredoxin.
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Affiliation(s)
- I R Vassiliev
- Department of Biochemistry and Molecular Biology, The Pennsylvania State University, University Park 16802, USA
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Molina-Heredia FP, Hervás M, Navarro JA, De la Rosa MA. Cloning and correct expression in Escherichia coli of the petE and petJ genes respectively encoding plastocyanin and cytochrome c6 from the cyanobacterium Anabaena sp. PCC 7119. Biochem Biophys Res Commun 1998; 243:302-6. [PMID: 9473522 DOI: 10.1006/bbrc.1997.7953] [Citation(s) in RCA: 39] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
The genes coding for plastocyanin (petE) and cytochrome c6 (petJ) from Anabaena sp. PCC 7119 have been cloned and properly expressed in Escherichia coli. The recombinant proteins are identical to those purified from the cyanobacterial cells. The products of both the petE and petJ genes are correctly processed in E. coli, as deduced from their identical N-terminal amino acid sequences as compared with those of the metalloproteins isolated from the cyanobacterium. Physicochemical and functional properties of the native and recombinant protein preparations are also identical, thereby confirming that expression of petE and petJ genes in E. coli is an adequate tool to address the study of the structure/function relationships in plastocyanin and cytochrome c6 from Anabaena by site-directed mutagenesis.
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Affiliation(s)
- F P Molina-Heredia
- Instituto de Bioquímica Vegetal y Fotosíntesis, Centro Isla de la Cartuja, Universidad de Sevilla, Spain
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