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Zakharov SD, Savikhin S, Misumi Y, Kurisu G, Cramer WA. Isothermal titration calorimetry of membrane protein interactions: FNR and the cytochrome b 6f complex. Biophys J 2022; 121:300-308. [PMID: 34902329 PMCID: PMC8790201 DOI: 10.1016/j.bpj.2021.12.014] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/26/2021] [Revised: 06/03/2021] [Accepted: 12/09/2021] [Indexed: 01/21/2023] Open
Abstract
Ferredoxin-NADP+ reductase (FNR) was previously inferred to bind to the cytochrome b6f complex in the electron transport chain of oxygenic photosynthesis. In the present study, this inference has been examined through analysis of the thermodynamics of the interaction between FNR and the b6f complex. Isothermal titration calorimetry (ITC) was used to characterize the physical interaction of FNR with b6f complex derived from two plant sources (Spinacia oleracea and Zea maize). ITC did not detect a significant interaction of FNR with the b6f complex in detergent solution nor with the complex reconstituted in liposomes. A previous inference of a small amplitude but defined FNR-b6f interaction is explained by FNR interaction with micelles of the undecyl β-D maltoside (UDM) detergent micelles used to purify b6f. Circular dichroism, employed to analyze the effect of detergent on the FNR structure, did not reveal significant changes in secondary or tertiary structures of FNR domains in the presence of UDM detergent. However, thermodynamic analysis implied a significant decrease in an interaction between the N-terminal FAD-binding and C-terminal NADP+-binding domains of FNR caused by detergent. The enthalpy, ΔHo, and the entropy, ΔSo, associated with FNR unfolding decreased four-fold in the presence of 1 mM UDM at pH 6.5. In addition to the conclusion regarding the absence of a binding interaction of significant amplitude between FNR and the b6f complex, these studies provide a precedent for consideration of significant background protein-detergent interactions in ITC analyses involving integral membrane proteins.
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Affiliation(s)
| | - Sergei Savikhin
- Department of Physics and Astronomy, Purdue University, West Lafayette, Indiana
| | - Yuko Misumi
- Department of Physics and Astronomy, Purdue University, West Lafayette, Indiana
| | - Genji Kurisu
- Institute for Protein Research, Osaka University, Suita, Osaka
| | - William A Cramer
- Department of Biological Sciences, Purdue University, West Lafayette, Indiana.
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2
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Kramer M, Rodriguez-Heredia M, Saccon F, Mosebach L, Twachtmann M, Krieger-Liszkay A, Duffy C, Knell RJ, Finazzi G, Hanke GT. Regulation of photosynthetic electron flow on dark to light transition by ferredoxin:NADP(H) oxidoreductase interactions. eLife 2021; 10:56088. [PMID: 33685582 PMCID: PMC7984839 DOI: 10.7554/elife.56088] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/17/2020] [Accepted: 02/25/2021] [Indexed: 01/12/2023] Open
Abstract
During photosynthesis, electron transport is necessary for carbon assimilation and must be regulated to minimize free radical damage. There is a longstanding controversy over the role of a critical enzyme in this process (ferredoxin:NADP(H) oxidoreductase, or FNR), and in particular its location within chloroplasts. Here we use immunogold labelling to prove that FNR previously assigned as soluble is in fact membrane associated. We combined this technique with a genetic approach in the model plant Arabidopsis to show that the distribution of this enzyme between different membrane regions depends on its interaction with specific tether proteins. We further demonstrate a correlation between the interaction of FNR with different proteins and the activity of alternative photosynthetic electron transport pathways. This supports a role for FNR location in regulating photosynthetic electron flow during the transition from dark to light.
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Affiliation(s)
- Manuela Kramer
- School of Biochemistry and Chemistry, Queen Mary University of London, London, United Kingdom.,Department of Plant Physiology, Faculty of Biology and Chemistry, University of Osnabrück, Osnabrück, Germany
| | | | - Francesco Saccon
- School of Biochemistry and Chemistry, Queen Mary University of London, London, United Kingdom
| | - Laura Mosebach
- Institute of Plant Biology and Biotechnology, University of Münster, Münster, Germany
| | - Manuel Twachtmann
- Department of Plant Physiology, Faculty of Biology and Chemistry, University of Osnabrück, Osnabrück, Germany
| | - Anja Krieger-Liszkay
- Institute for Integrative Biology of the Cell (I2BC), CEA, CNRS, Univ Paris-Sud, Université Paris-Saclay, Paris, France
| | - Chris Duffy
- School of Biochemistry and Chemistry, Queen Mary University of London, London, United Kingdom
| | - Robert J Knell
- School of Biochemistry and Chemistry, Queen Mary University of London, London, United Kingdom
| | - Giovanni Finazzi
- Laboratoire de Physiologie Cellulaire et Végétale, UMR 5168, Centre National de la Recherche Scientifique (CNRS), Commissariat a` l'Energie Atomique et aux Energies Alternatives (CEA), Université Grenoble Alpes, Institut National Recherche Agronomique (INRA), Institut de Recherche en Sciences et Technologies pour le Vivant (iRTSV), CEA Grenoble, Grenoble, France
| | - Guy Thomas Hanke
- School of Biochemistry and Chemistry, Queen Mary University of London, London, United Kingdom.,Department of Plant Physiology, Faculty of Biology and Chemistry, University of Osnabrück, Osnabrück, Germany
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3
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Binding of ferredoxin NADP + oxidoreductase (FNR) to plant photosystem I. BIOCHIMICA ET BIOPHYSICA ACTA-BIOENERGETICS 2019; 1860:689-698. [PMID: 31336103 DOI: 10.1016/j.bbabio.2019.07.007] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Subscribe] [Scholar Register] [Received: 04/02/2019] [Revised: 07/11/2019] [Accepted: 07/18/2019] [Indexed: 12/17/2022]
Abstract
The binding of FNR to PSI has been postulated long ago, however, a clear evidence is still missing. In this work, using isothermal titration calorimetry (ITC), we found that FNR binds to photosystem I with its light harvesting complex I (PSI-LHCI) from C. reinhardtii with a 1:1 stoichiometry, a Kd of ~0.8 μM and ∆H of -20.7 kcal/mol. Titrations at different temperatures were used to determine the heat capacity change, ∆CP, of the binding, through which the size of the interface area between the proteins was assessed as ~3000 Å2. In a different set of ITC experiments, introduction of various sucrose concentrations was used to estimate that ~95 water molecules are released to the solvent. These observations support the notion of a binding site shared by few of the photosystem I - light harvesting complex I (PSI-LHCI) subunits in addition to PsaE. Based on these results, a hypothetical model was built for the binding site of FNR at PSI, using known crystallographic structures of: cyanobacterial PSI in complex with ferredoxin (Fd), plant PSI-LHCI and Fd:FNR complex from cyanobacteria. FNR binding site location is proposed to be at the foot of the stromal ridge and above the inner LHCI belt. It is expected to form contacts with PsaE, PsaB, PsaF and at least one of the LHCI. In addition, a ~4.5-fold increased affinity between FNR and PSI-LHCI under crowded 1 M sucrose environment led us to conclude that in C. reinhardtii FNR also functions as a subunit of PSI-LHCI.
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4
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Kim YM, Bouras N, Kav NNV, Strelkov SE. Inhibition of photosynthesis and modification of the wheat leaf proteome by Ptr ToxB: A host-specific toxin from the fungal pathogen Pyrenophora tritici-repentis. Proteomics 2010; 10:2911-26. [DOI: 10.1002/pmic.200900670] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
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5
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Moolna A, Bowsher CG. The physiological importance of photosynthetic ferredoxin NADP+ oxidoreductase (FNR) isoforms in wheat. JOURNAL OF EXPERIMENTAL BOTANY 2010; 61:2669-81. [PMID: 20410318 PMCID: PMC2882262 DOI: 10.1093/jxb/erq101] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/08/2023]
Abstract
Ferredoxin NADP(+) oxidoreductase (FNR) enzymes catalyse electron transfer between ferredoxin and NADPH. In plants, a photosynthetic FNR (pFNR) transfers electrons from reduced ferredoxin to NADPH for the final step of linear electron flow, providing reductant for carbon fixation. pFNR is also thought to play important roles in two different mechanisms of cyclic electron flow around photosystem I; and photosynthetic reductant is itself partitioned between competing linear, cyclic, and alternative electron flow pathways. Four pFNR protein isoforms in wheat that display distinct reaction kinetics with leaf-type ferredoxin have previously been identified. It has been suggested that these isoforms may be crucial to the regulation of reductant partition between carbon fixation and other metabolic pathways. Here the 12 cm primary wheat leaf has been used to show that the alternative N-terminal pFNRI and pFNRII protein isoforms have statistically significant differences in response to the physiological parameters of chloroplast maturity, nitrogen regime, and oxidative stress. More specifically, the results obtained suggest that the alternative N-terminal forms of pFNRI have distinct roles in the partitioning of photosynthetic reductant. The role of alternative N-terminal processing of pFNRI is also discussed in terms of its importance for thylakoid targeting. The results suggest that the four pFNR protein isoforms are each present in the chloroplast in phosphorylated and non-phosphorylated states. pFNR isoforms vary in putative phosphorylation responses to physiological parameters, but the physiological significance requires further investigation.
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Morsy FM, Nakajima M, Yoshida T, Fujiwara T, Sakamoto T, Wada K. Subcellular localization of ferredoxin-NADP(+) oxidoreductase in phycobilisome retaining oxygenic photosysnthetic organisms. PHOTOSYNTHESIS RESEARCH 2008; 95:73-85. [PMID: 17828614 DOI: 10.1007/s11120-007-9235-4] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/27/2007] [Accepted: 07/19/2007] [Indexed: 05/17/2023]
Abstract
Ferredoxin-NADP(+) oxidoreductase (FNR) catalyzing the terminal step of the linear photosynthetic electron transport was purified from the cyanobacterium Spirulina platensis and the red alga Cyanidium caldarium. FNR of Spirulina consisted of three domains (CpcD-like domain, FAD-binding domain, and NADP(+)-binding domain) with a molecular mass of 46 kDa and was localized in either phycobilisomes or thylakoid membranes. The membrane-bound FNR with 46 kDa was solublized by NaCl and the solublized FNR had an apparent molecular mass of 90 kDa. FNR of Cyanidium consisted of two domains (FAD-binding domain and NADP(+)-binding domain) with a molecular mass of 33 kDa. In Cyanidium, FNR was found on thylakoid membranes, but there was no FNR on phycobilisomes. The membrane-bound FNR of Cyanidium was not solublized by NaCl, suggesting the enzyme is tightly bound in the membrane. Although both cyanobacteria and red algae are photoautotrophic organisms bearing phycobilisomes as light harvesting complexes, FNR localization and membrane-binding characteristics were different. These results suggest that FNR binding to phycobilisomes is not characteristic for all phycobilisome retaining oxygenic photosynthetic organisms, and that the rhodoplast of red algae had possibly originated from a cyanobacterium ancestor, whose FNR lacked the CpcD-like domain.
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Affiliation(s)
- Fatthy Mohamed Morsy
- Division of Life Science, Graduate School of Natural Science and Technology, Kanazawa University, Kakuma, Kanazawa, Ishikawa, 920-1192, Japan
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Ohtsuka M, Oyabu J, Kashino Y, Satoh K, Koike H. Inactivation of ycf33 Results in an Altered Cyclic Electron Transport Pathway Around Photosystem I in Synechocystis sp. PCC6803. ACTA ACUST UNITED AC 2004; 45:1243-51. [PMID: 15509847 DOI: 10.1093/pcp/pch147] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Abstract
ycf33 encodes a small protein with a molecular mass of 7.5 kDa and is found from cyanobacteria to higher plants. A ycf33 deletion mutant was constructed in Synechocystis sp. PCC6803 and characterized. The mutant showed a higher phycobilisome/chlorophyll ratio than the wild type and a higher photosystem II/photosystem I fluorescence ratio measured at 77 K. Under photoautotrophic conditions, the growth rates were not much different from those of the wild type. Cyclic electron transport activities around photosystem I were not much different between the wild type and the mutant. However, the effects of diphenyleneiodonium, an inhibitor of flavoprotein, on cyclic electron transport in the mutant were different from those in the wild type; it was severely inhibited in the wild type but not much in the mutant. Together with the effects of nitrite, which accepts electrons from ferredoxin via nitrite reductase and those of HgCl2, it was suggested that the pathway of cyclic electron transport is altered in the mutant.
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Affiliation(s)
- Masako Ohtsuka
- Department of Life Science, Graduate School of Life Science, University of Hyogo, Harima Science Garden City, Hyogo, 678-1297 Japan
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8
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9
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Clark R, Hawkesford M, Coughlan S, Bennett J, Hind G. Association of ferredoxin-NADP+
oxidoreductase with the chloroplast cytochrome b-f
complex. FEBS Lett 2001. [DOI: 10.1016/0014-5793(84)81092-3] [Citation(s) in RCA: 83] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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10
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Su X, Fraenkel P, Bogorad L. Excitation energy transfer from phycocyanin to chlorophyll in an apcA-defective mutant of Synechocystis sp. PCC 6803. J Biol Chem 1992. [DOI: 10.1016/s0021-9258(18)50038-7] [Citation(s) in RCA: 23] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022] Open
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11
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Andersen B, Scheller HV, Møller BL. The PSI-E subunit of photosystem I binds ferredoxin:NADP+ oxidoreductase. FEBS Lett 1992; 311:169-73. [PMID: 1397306 DOI: 10.1016/0014-5793(92)81391-x] [Citation(s) in RCA: 115] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Abstract
A photosystem I complex containing the polypeptides PSI-A to PSI-L, light-harvesting complex I and ferredoxin:NADP+ oxidoreductase has been isolated from barley using the non-ionic detergent n-decyl-beta-D-maltopyranoside. The ratio between bound ferredoxin:NADP+ oxidoreductase and P700 is 0.4 +/- 0.2. The complex is highly active in catalyzing light-induced transfer of electrons from plastocyanin to NADP+ at rates of 280 +/- 150 and 1800 +/- 800 mumol NADPH/(mg chl.h), without and in the presence of saturating amounts of exogenously added ferredoxin:NADP+ oxidoreductase, respectively. Endogenously bound ferredoxin:NADP+ oxidoreductase interacts with the PSI-E subunit as demonstrated by cross-linking experiments using two different types of cross-linkers and identification of the products by Western blotting and the use of monospecific antibodies.
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Affiliation(s)
- B Andersen
- Department of Plant Biology, Royal Veterinary and Agricultural University, Copenhagen, Denmark
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12
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Gebhart UB, Maier TL, Stevanović S, Bayer MG, Schenk HE. Ferredoxin:NADP oxidoreductase of Cyanophora paradoxa: purification, partial characterization, and N-terminal amino acid sequence. Protein Expr Purif 1992; 3:228-35. [PMID: 1392619 DOI: 10.1016/1046-5928(92)90019-s] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Abstract
The ferredoxin:NADP+ oxidoreductase of the protist Cyanophora paradoxa, as a descendant of a former symbiotic consortium, an important model organism in view of the Endosymbiosis Theory, is the first enzyme purified from a formerly original endocytobiont (cyanelle) that is found to be encoded in the nucleus of the host. This cyanoplast enzyme was isolated by FPLC (19% yield) and characterized with respect to the uv-vis spectrum, pH optimum (pH 9), molecular mass of 34 kDa, and an N-terminal amino acid sequence (24 residues). The enzyme shows, as known from other organisms, molecular heterogeneity. The N-terminus of a further ferredoxin:NADP+ oxidoreductase polypeptide represents a shorter sequence missing the first four amino acids of the mature enzyme.
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Affiliation(s)
- U B Gebhart
- Botanical Institute, University of Tübingen, Germany
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13
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Hodges M, Miginiac-Maslow M, Le Maréchal P, Rémy R. The ATP-dependent post translational modification of ferredoxin: NADP+ oxidoreductase. BIOCHIMICA ET BIOPHYSICA ACTA 1990; 1052:446-52. [PMID: 2191725 DOI: 10.1016/0167-4889(90)90154-6] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Abstract
Incubation of thylakoids with purified FNR and [32P]ATP led to the incorporation of phosphate into the FNR. In the absence of added FNR, 32P-labelled FNR could be detected associated with the thylakoids. An amino-acid analysis showed that in the dark, the FNR could be phosphorylated on a serine residue. In the presence of thylakoids, the FNR contained a threonine phosphate which was associated with a light-dependent reaction. The physiological function of this phosphorylation is not clear. Some modifications in NADP(+)-dependent photosystem I (PSI) activity and FNR-membrane association have been observed on the addition of ATP. Whether these changes are linked to the phosphorylation of the FNR remain to be fully elucidated.
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Affiliation(s)
- M Hodges
- Laboratoire de Physiologie Végétale Moléculaire, CNRS (UA1128), Université de Paris Sud, Orsay, France
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14
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The chloroplast reductase-binding protein is identical to the 16.5-kDa polypeptide described as a component of the oxygen-evolving complex. J Biol Chem 1989. [DOI: 10.1016/s0021-9258(19)30053-5] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
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15
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Soncini FC, Vallejos RH. Immunodetection of the Ferredoxin-NADP Oxidoreductase-Binding Protein Complex in Thylakoids of Different Higher Plant Species. PLANT PHYSIOLOGY 1989; 90:372-5. [PMID: 16666777 PMCID: PMC1061729 DOI: 10.1104/pp.90.2.372] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/09/2023]
Abstract
Monospecific polyclonal antibodies against thylakoid ferredoxin-NADP(+) oxidoreductase and its binding protein from Spinacia oleracea were used to detect the presence of these proteins in different higher plants, including C(3), C(4), and Crassulacean acid metabolism species. A remarkable conservation of antigenic determinants in all the species analyzed was demonstrated for both the reductase and its binding protein. The association of these polypeptides in a complex was detected by immunoprecipitation.
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Affiliation(s)
- F C Soncini
- Centro de Estudios Fotosintéticos y Bioquímicos (CONICET, F.M.Lillo, U.N.R.), Suipacha 531, 2000 Rosario, Argentina
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16
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Chemical modification of the active site of ferredoxin-NADP+ reductase and conformation of the binary ferredoxin/ferredoxin-NADP+ reductase complex in solution. BIOCHIMICA ET BIOPHYSICA ACTA-BIOENERGETICS 1988. [DOI: 10.1016/0005-2728(88)90002-3] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
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17
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Newman BJ, Gray JC. Characterisation of a full-length cDNA clone for pea ferredoxin-NADP(+) reductase. PLANT MOLECULAR BIOLOGY 1988; 10:511-520. [PMID: 24277623 DOI: 10.1007/bf00033606] [Citation(s) in RCA: 63] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/15/1987] [Accepted: 02/12/1988] [Indexed: 06/02/2023]
Abstract
Ferredoxin-NADP(+) reductase has been purified to homogeneity from pea leaves and has been resolved into two forms by ion exchange chromatography and SDS gel electrophoresis. Antibodies to the proteins have been used to isolate pea leaf cDNA clones from a library in λgt11. A full-length clone of 1 400 bp encodes a polypeptide of 360 amino acid residues, of which 52 residues constitute an N-terminal transit peptide and 308 residues make up the mature protein. Transcription and translation of the cDNA in vitro produces a protein of 40 kDa, which is imported by isolated pea chloroplasts and processed to the mature 34 kDa protein. Southern hybridisation to pea genomic DNA indicates that there are probably two genes in the haploid genome.
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Affiliation(s)
- B J Newman
- Botany School, University of Cambridge, CB2 3EA, Cambridge, UK
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18
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Pschorn R, Rühle W, Wild A. Structure and function of ferredoxin-NADP(+)-oxidoreductase. PHOTOSYNTHESIS RESEARCH 1988; 17:217-229. [PMID: 24429769 DOI: 10.1007/bf00035449] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/11/1987] [Accepted: 04/01/1988] [Indexed: 06/03/2023]
Abstract
The redox-enzyme ferredoxin-NADP-oxidoreductase has been shown to be activated by light and inactivated in the dark. This review will summarize recent data concerning the biochemical characterization of the enzyme compared to its in-vivo activation. Further-more the mechanism of this activation process is discussed as a conformational change caused by the light-driven proton gradient.
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Affiliation(s)
- R Pschorn
- Institut für Allgemeine Botanik der Johannes Gutenberg-Universität, Saarstr. 21, D-6500, Mainz, Federal Republic of Germany
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19
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Rühle W, Pschorn R, Wild A. Regulation of the photosynthetic electron transport during dark-light transitions by activation of the ferredoxin-NADP(+)-oxidoreductase in higher plants. PHOTOSYNTHESIS RESEARCH 1987; 11:161-171. [PMID: 24435492 DOI: 10.1007/bf00018274] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/24/1986] [Revised: 05/09/1986] [Indexed: 06/03/2023]
Abstract
Absorbance changes associated with the oxidation and reduction of cytochrome f belong to the classical observations about the interaction of the two photosystems. A complex induction pattern of cytochrome f oxidation results, if both photosystems are excited simultaneously. This indicates a light-modulated regulation of the photosynthetic electron transport, which we examined for intact biological systems of decreasing complexity. The ferredoxin-NADP(+)-oxidoreductase (FNR) is suggested to be activated by light and inactivated in the dark. This is pointed out by the kinetics of variable fluorescence and by the influence of different artificial electron acceptors on the cytochrome f kinetics. The photoreduction of NADP(+) by carefully prepared thylakoids demonstrates the activation process directly.
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Affiliation(s)
- W Rühle
- Institut für Allgemeine Botanik, Saarstr. 21, D-6500, Mainz, Federal Republic of Germany
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20
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Armstrong FA, Corbett SG. Inhibition of ferredoxin: NADP+ reductase activity by the hexacyanochromate (III) ion. Biochem Biophys Res Commun 1986; 141:578-83. [PMID: 3801016 DOI: 10.1016/s0006-291x(86)80212-1] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023]
Abstract
The small inorganic complex Cr(CN)6(3-) is a clean inhibitor of the ferredoxin: NADP+ reductase-catalysed oxidation of reduced spinach ferredoxin by NADP+. Independent spectrophotometric measurements show that millimolar additions of Cr(CN)6(3-) to mixtures of ferredoxin and ferredoxin NADP+ reductase give a marked attenuation of the difference spectrum characteristic of ferredoxin-ferredoxin: NADP+ reductase complex formation. Since there is no evidence, from NMR studies, for significant binding of Cr(CN)6(3-) to ferredoxin, these results indicate that Cr(CN)6(3-) binds to ferredoxin: NADP+ reductase at a site which is crucial to its interaction with the electron-transfer protein. The effective kinetic binding constant for Cr(CN)6(3-), measured at low ferredoxin concentration, is 445 M-1 (ie Kdiss congruent to 2 mM) at 25 degrees, pH7.5, I = 0.10 M. With assumption of a simple electrostatic interaction, an enzyme domain with an effective charge of 3+/4+ is proposed.
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21
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Serrano A, Soncini FC, Vallejos RH. Localization and Quantitative Determination of Ferredoxin-NADP Oxidoreductase, a Thylakoid-Bound Enzyme in the Cyanobacterium Anabaena sp. Strain 7119. PLANT PHYSIOLOGY 1986; 82:499-502. [PMID: 16665058 PMCID: PMC1056148 DOI: 10.1104/pp.82.2.499] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/09/2023]
Abstract
Thylakoid membrane preparations obtained from mechanically disrupted (sonicated) cells of the cyanobacterium Anabaena sp. strain 7119 show a membrane-bound ferredoxin-NADP(+) oxidoreductase (EC 1.18.1.2) as determined either by specific antibodies or by using the ferredoxin-dependent NADPH-cytochrome c reductase activity, which is a specific test for this enzyme. However, in contrast with higher plant thylakoids, a low yield of the cyanobacterial reductase-only about 20% of the total amount of this protein estimated in whole cell homogenates-was obtained as a membrane-bound form when Mg(2+) was present during the disruption treatment. It is noteworthy that the addition of water-soluble nonionic polymers, namely polyethylene glycol and polyyinylpyrrolidone, dramatically increased the yield of the thylakoid-bound reductase, reaching values up to 80 to 85% of the total enzyme. Using these thylakoid membrane preparations, a quantitative determination of the reductase has been performed for the first time for cyanobacterial thylakoids. The value determined by immunoelectrophoresis-from 8 to 10 nanomoles per micromole of chlorophyll-is clearly higher than those reported for chloroplast thylakoids.
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Affiliation(s)
- A Serrano
- Centro de Estudios Fotosintéticos y Bioquímicos, Consejo Nacional de Investigaciones Científicas y Técnicas, Fundación Miguel Lillo, Universidad Nacional de Rosario, Suipacha 531, 2000 Rosario, Argentina
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22
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Removal of ferredoxin:NADP+ oxidoreductase from thylakoid membranes, rebinding to depleted membranes, and identification of the binding site. J Biol Chem 1986. [DOI: 10.1016/s0021-9258(18)67216-3] [Citation(s) in RCA: 64] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
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23
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Coughlan S, Matthijs HC, Hind G. The ferredoxin-NADP+ oxidoreductase-binding protein is not the 17-kDa component of the cytochrome b/f complex. J Biol Chem 1985. [DOI: 10.1016/s0021-9258(18)95675-9] [Citation(s) in RCA: 18] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022] Open
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Carrillo N, Vallejos RH. The light-dependent modulation of photosynthetic electron transport. Trends Biochem Sci 1983. [DOI: 10.1016/0968-0004(83)90389-4] [Citation(s) in RCA: 30] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
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Functional sulfhydryl groups of ferredoxin-NADP+ oxidoreductase. BIOCHIMICA ET BIOPHYSICA ACTA-BIOENERGETICS 1982. [DOI: 10.1016/0005-2728(82)90183-9] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
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