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Adobor S, Banniza S, Vandenberg A, Purves RW. Untargeted profiling of secondary metabolites and phytotoxins associated with stemphylium blight of lentil. PLANTA 2023; 257:73. [PMID: 36864322 DOI: 10.1007/s00425-023-04105-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/13/2022] [Accepted: 02/21/2023] [Indexed: 06/18/2023]
Abstract
Stemphylium botryosum alters lentil secondary metabolism and differentially affects resistant and susceptible genotypes. Untargeted metabolomics identifies metabolites and their potential biosynthetic pathways that play a crucial role in resistance to S. botryosum. The molecular and metabolic processes that mediate resistance to stemphylium blight caused by Stemphylium botryosum Wallr. in lentil are largely unknown. Identifying metabolites and pathways associated with Stemphylium infection may provide valuable insights and novel targets to breed for enhanced resistance. The metabolic changes following infection of four lentil genotypes by S. botryosum were investigated by comprehensive untargeted metabolic profiling employing reversed-phase or hydrophilic interaction liquid chromatography (HILIC) coupled to a Q-Exactive mass spectrometer. At the pre-flowering stage, plants were inoculated with S. botryosum isolate SB19 spore suspension and leaf samples were collected at 24, 96 and 144 h post-inoculation (hpi). Mock-inoculated plants were used as negative controls. After analyte separation, high-resolution mass spectrometry data was acquired in positive and negative ionization modes. Multivariate modeling revealed significant treatment, genotype and hpi effects on metabolic profile changes that reflect lentil response to Stemphylium infection. In addition, univariate analyses highlighted numerous differentially accumulated metabolites. By contrasting the metabolic profiles of SB19-inoculated and mock-inoculated plants and among lentil genotypes, 840 pathogenesis-related metabolites were detected including seven S. botryosum phytotoxins. These metabolites included amino acids, sugars, fatty acids and flavonoids in primary and secondary metabolism. Metabolic pathway analysis revealed 11 significant pathways including flavonoid and phenylpropanoid biosynthesis, which were affected upon S. botryosum infection. This research contributes to ongoing efforts toward a comprehensive understanding of the regulation and reprogramming of lentil metabolism under biotic stress, which will provide targets for potential applications in breeding for enhanced disease resistance.
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Affiliation(s)
- Stanley Adobor
- Pulse Crop Breeding and Genetics, Department of Plant Sciences, Crop Development Centre, University of Saskatchewan, Saskatoon, SK, Canada.
| | - Sabine Banniza
- Pulse Crop Breeding and Genetics, Department of Plant Sciences, Crop Development Centre, University of Saskatchewan, Saskatoon, SK, Canada
| | - Albert Vandenberg
- Pulse Crop Breeding and Genetics, Department of Plant Sciences, Crop Development Centre, University of Saskatchewan, Saskatoon, SK, Canada
| | - Randy W Purves
- College of Pharmacy and Nutrition, University of Saskatchewan, Saskatoon, SK, Canada.
- Centre for Veterinary Drug Residues, Canadian Food Inspection Agency, Saskatoon, SK, Canada.
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2
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Positive Selection in the Chloroplastic ATP-Synthase β-Subunit and Its Relation to Virulence Factors. J Mol Evol 2020; 88:703-713. [PMID: 33029646 DOI: 10.1007/s00239-020-09968-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/10/2020] [Accepted: 09/27/2020] [Indexed: 10/23/2022]
Abstract
The most paradigmatic examples of molecular evolution under positive selection involve genes related to the immune system. Recently, different chloroplastic factors have been shown to be important for plant defenses, among them, the α- and β-subunits of the ATP synthase. The β-subunit has been reported to interact with several viral proteins while both proteins have been implicated with sensitivity to tentoxin, a phytotoxin produced by the widespread fungus Alternaria alternata. Given the relation of both protein to virulence factors, we studied whether these proteins are evolving under positive selection. To this end, we used the dN/dS ratio to examine possible sites under positive selection in several Angiosperm clades. After examining 79 plant genera and 1232 species, we found three times more sites under pervasive diversifying selection in the N-terminal region of the β-subunit compared to the α-subunit, supporting previous results which identified this region as responsible for interacting with viral proteins. Moreover, we found the site 83 of β-subunit under positive selection in several plant genera, a site clearly related to the sensitivity to tentoxin according to biochemistry assays, which possibly reflects the selective pressure of the non-host specific tentoxin across various Angiosperm clades.
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Wang ZF, Sun ZC, Xiao L, Zhou YM, Du FY. Herbicidal Polyketides and Diketopiperazine Derivatives from Penicillium viridicatum. JOURNAL OF AGRICULTURAL AND FOOD CHEMISTRY 2019; 67:14102-14109. [PMID: 31790231 DOI: 10.1021/acs.jafc.9b06116] [Citation(s) in RCA: 20] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/10/2023]
Abstract
Herbicidal activity-guided isolation from the fermentation extract of Penicillium viridicatum had obtained two herbicidal series of polyketides (1-7) and diketopiperazine derivatives (8-11), especially including three novel polyketides (1-3). The structures and absolute configurations of new polyketides 1-3 were elucidated by extensive spectroscopic analyses, as well as comparisons between measured and calculated ECD spectra. Novel polyketides 1-3 and known 4, all bearing the heptaketide skeleton with a trans-fused decalin ring of 8-CH3 substitution, could significantly inhibit the radicle growth of Echinochloa crusgalli seedlings with a dose-dependent relationship. Especially at the concentration of 10 μg/mL, 1-4 exhibited the inhibition rates with 81.5% ± 2.0, 76.4% ± 0.8, 79.6% ± 1.1, and 80.0 ± 1.8%, respectively, even better than the commonly used synthetic herbicide of acetochlor with 76.1 ± 1.4%. Further greenhouse bioassay revealed that 4 showed pre-emergence herbicidal activity against E. crusgalli with the fresh-weight inhibition rate of 74.1% at a dosage of 400 g ai/ha, also better than acetochlor, while the other isolated metabolites (5-11) exhibited moderate herbicidal activities. The structure-activity differences of isolated polyketides indicated that the heptaketide skeleton, characterized by a trans-fused decalin ring with 8-CH3 substitution, should be the key factor of their herbicidal activities, which could give new insights for the bioherbicide developments.
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Interactions involved in grasping and locking of the inhibitory peptide IF1 by mitochondrial ATP synthase. BIOCHIMICA ET BIOPHYSICA ACTA-BIOENERGETICS 2014; 1837:761-72. [DOI: 10.1016/j.bbabio.2014.01.023] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/30/2013] [Revised: 01/24/2014] [Accepted: 01/29/2014] [Indexed: 11/23/2022]
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Lou J, Fu L, Peng Y, Zhou L. Metabolites from Alternaria fungi and their bioactivities. Molecules 2013; 18:5891-935. [PMID: 23698046 PMCID: PMC6270608 DOI: 10.3390/molecules18055891] [Citation(s) in RCA: 161] [Impact Index Per Article: 14.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/18/2013] [Revised: 05/06/2013] [Accepted: 05/16/2013] [Indexed: 01/10/2023] Open
Abstract
Alternaria is a cosmopolitan fungal genus widely distributing in soil and organic matter. It includes saprophytic, endophytic and pathogenic species. At least 268 metabolites from Alternaria fungi have been reported in the past few decades. They mainly include nitrogen-containing metabolites, steroids, terpenoids, pyranones, quinones, and phenolics. This review aims to briefly summarize the structurally different metabolites produced by Alternaria fungi, as well as their occurrences, biological activities and functions. Some considerations related to synthesis, biosynthesis, production and applications of the metabolites from Alternaria fungi are also discussed.
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Affiliation(s)
| | | | | | - Ligang Zhou
- MOA Key Laboratory of Plant Pathology, Department of Plant Pathology, College of Agronomy and Biotechnology, China Agricultural University, Beijing 100193, China
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Shi LX, Theg SM. Energetic cost of protein import across the envelope membranes of chloroplasts. Proc Natl Acad Sci U S A 2013; 110:930-5. [PMID: 23277572 PMCID: PMC3549074 DOI: 10.1073/pnas.1115886110] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Chloroplasts are the organelles of green plants in which light energy is transduced into chemical energy, forming ATP and reduced carbon compounds upon which all life depends. The expenditure of this energy is one of the central issues of cellular metabolism. Chloroplasts contain ~3,000 proteins, among which less than 100 are typically encoded in the plastid genome. The rest are encoded in the nuclear genome, synthesized in the cytosol, and posttranslationally imported into the organelle in an energy-dependent process. We report here a measurement of the amount of ATP hydrolyzed to import a protein across the chloroplast envelope membranes--only the second complete accounting of the cost in Gibbs free energy of protein transport to be undertaken. Using two different precursors prepared by three distinct techniques, we show that the import of a precursor protein into chloroplasts is accompanied by the hydrolysis of ~650 ATP molecules. This translates to a ΔG(protein) (transport) of some 27,300 kJ/mol protein imported. We estimate that protein import across the plastid envelope membranes consumes ~0.6% of the total light-saturated energy output of the organelle.
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Affiliation(s)
- Lan-Xin Shi
- Department of Plant Biology, University of California, Davis, CA 95616
| | - Steven M. Theg
- Department of Plant Biology, University of California, Davis, CA 95616
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Duke SO, Dayan FE. Clues to New Herbicide Mechanisms of Action from Natural Sources. ACS SYMPOSIUM SERIES 2013. [DOI: 10.1021/bk-2013-1141.ch014] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Affiliation(s)
- Stephen O. Duke
- Natural Products Utilization Research, Agricultural Research Service, University, Mississippi 38677, U.S.A
| | - Franck E. Dayan
- Natural Products Utilization Research, Agricultural Research Service, University, Mississippi 38677, U.S.A
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Dayan FE, Owens DK, Duke SO. Rationale for a natural products approach to herbicide discovery. PEST MANAGEMENT SCIENCE 2012; 68:519-28. [PMID: 22232033 DOI: 10.1002/ps.2332] [Citation(s) in RCA: 89] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/26/2011] [Accepted: 10/12/2011] [Indexed: 05/22/2023]
Abstract
Weeds continue to evolve resistance to all the known modes of herbicidal action, but no herbicide with a new target site has been commercialized in nearly 20 years. The so-called 'new chemistries' are simply molecules belonging to new chemical classes that have the same mechanisms of action as older herbicides (e.g. the protoporphyrinogen-oxidase-inhibiting pyrimidinedione saflufenacil or the very-long-chain fatty acid elongase targeting sulfonylisoxazoline herbicide pyroxasulfone). Therefore, the number of tools to manage weeds, and in particular those that can control herbicide-resistant weeds, is diminishing rapidly. There is an imminent need for truly innovative classes of herbicides that explore chemical spaces and interact with target sites not previously exploited by older active ingredients. This review proposes a rationale for a natural-products-centered approach to herbicide discovery that capitalizes on the structural diversity and ingenuity afforded by these biologically active compounds. The natural process of extended-throughput screening (high number of compounds tested on many potential target sites over long periods of times) that has shaped the evolution of natural products tends to generate molecules tailored to interact with specific target sites. As this review shows, there is generally little overlap between the mode of action of natural and synthetic phytotoxins, and more emphasis should be placed on applying methods that have proved beneficial to the pharmaceutical industry to solve problems in the agrochemical industry.
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Affiliation(s)
- Franck E Dayan
- United States Department of Agriculture, Agricultural Research Service, University, MS 38677, USA.
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Duke SO, Dayan FE. Modes of action of microbially-produced phytotoxins. Toxins (Basel) 2011; 3:1038-1064. [PMID: 22069756 PMCID: PMC3202864 DOI: 10.3390/toxins3081038] [Citation(s) in RCA: 71] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/28/2011] [Revised: 08/15/2011] [Accepted: 08/17/2011] [Indexed: 01/17/2023] Open
Abstract
Some of the most potent phytotoxins are synthesized by microbes. A few of these share molecular target sites with some synthetic herbicides, but many microbial toxins have unique target sites with potential for exploitation by the herbicide industry. Compounds from both non-pathogenic and pathogenic microbes are discussed. Microbial phytotoxins with modes of action the same as those of commercial herbicides and those with novel modes of action of action are covered. Examples of the compounds discussed are tentoxin, AAL-toxin, auscaulitoxin aglycone, hydantocidin, thaxtomin, and tabtoxin.
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Affiliation(s)
- Stephen O. Duke
- United States Department of Agriculture, Agricultural Research Service, Natural Products Utilization Research Unit, P. O. Box 8048, MS 38677, USA;
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Perrin L, Loiseau N, André F, Delaforge M. Metabolism of N-methyl-amide by cytochrome P450s. FEBS J 2011; 278:2167-78. [DOI: 10.1111/j.1742-4658.2011.08133.x] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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11
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Chivasa S, Tomé DFA, Hamilton JM, Slabas AR. Proteomic analysis of extracellular ATP-regulated proteins identifies ATP synthase beta-subunit as a novel plant cell death regulator. Mol Cell Proteomics 2011; 10:M110.003905. [PMID: 21156838 PMCID: PMC3047153 DOI: 10.1074/mcp.m110.003905] [Citation(s) in RCA: 53] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/03/2010] [Revised: 11/24/2010] [Indexed: 12/27/2022] Open
Abstract
Extracellular ATP is an important signal molecule required to cue plant growth and developmental programs, interactions with other organisms, and responses to environmental stimuli. The molecular targets mediating the physiological effects of extracellular ATP in plants have not yet been identified. We developed a well characterized experimental system that depletes Arabidopsis cell suspension culture extracellular ATP via treatment with the cell death-inducing mycotoxin fumonisin B1. This provided a platform for protein profile comparison between extracellular ATP-depleted cells and fumonisin B1-treated cells replenished with exogenous ATP, thus enabling the identification of proteins regulated by extracellular ATP signaling. Using two-dimensional difference in-gel electrophoresis and matrix-assisted laser desorption-time of flight MS analysis of microsomal membrane and total soluble protein fractions, we identified 26 distinct proteins whose gene expression is controlled by the level of extracellular ATP. An additional 48 proteins that responded to fumonisin B1 were unaffected by extracellular ATP levels, confirming that this mycotoxin has physiological effects on Arabidopsis that are independent of its ability to trigger extracellular ATP depletion. Molecular chaperones, cellular redox control enzymes, glycolytic enzymes, and components of the cellular protein degradation machinery were among the extracellular ATP-responsive proteins. A major category of proteins highly regulated by extracellular ATP were components of ATP metabolism enzymes. We selected one of these, the mitochondrial ATP synthase β-subunit, for further analysis using reverse genetics. Plants in which the gene for this protein was knocked out by insertion of a transfer-DNA sequence became resistant to fumonisin B1-induced cell death. Therefore, in addition to its function in mitochondrial oxidative phosphorylation, our study defines a new role for ATP synthase β-subunit as a pro-cell death protein. More significantly, this protein is a novel target for extracellular ATP in its function as a key negative regulator of plant cell death.
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Affiliation(s)
- Stephen Chivasa
- From the ‡School of Biological and Biomedical Sciences, Durham University, Durham DH1 3LE, United Kingdom
| | - Daniel F. A. Tomé
- From the ‡School of Biological and Biomedical Sciences, Durham University, Durham DH1 3LE, United Kingdom
| | - John M. Hamilton
- From the ‡School of Biological and Biomedical Sciences, Durham University, Durham DH1 3LE, United Kingdom
| | - Antoni R. Slabas
- From the ‡School of Biological and Biomedical Sciences, Durham University, Durham DH1 3LE, United Kingdom
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Sunamura EI, Konno H, Imashimizu-Kobayashi M, Sugano Y, Hisabori T. Physiological impact of intrinsic ADP inhibition of cyanobacterial FoF1 conferred by the inherent sequence inserted into the gammasubunit. PLANT & CELL PHYSIOLOGY 2010; 51:855-65. [PMID: 20421199 DOI: 10.1093/pcp/pcq061] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/07/2023]
Abstract
The F(o)F(1)-ATPase, which synthesizes ATP with a rotary motion, is highly regulated in vivo in order to function efficiently, although there remains a limited understanding of the physiological significance of this regulation. Compared with its bacterial and mitochondrial counterparts, the gamma subunit of cyanobacterial F(1), which makes up the central shaft of the motor enzyme, contains an additional inserted region. Although deletion of this region results in the acceleration of the rate of ATP hydrolysis, the functional significance of the region has not yet been determined. By analysis of rotation, we successfully determined that this region confers the ability to shift frequently into an ADP inhibition state; this is a highly conserved regulatory mechanism which prevents ATP synthase from carrying out the reverse reaction. We believe that the physiological significance of this increased likelihood of shifting into the ADP inhibition state allows the intracellular ATP levels to be maintained, which is especially critical for photosynthetic organisms.
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Affiliation(s)
- Ei-Ichiro Sunamura
- Chemical Resources Laboratory, Tokyo Institute of Technology, Nagatsuta 4259-R1-8, Midori-Ku, Yokohama 226-8503, Japan
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13
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Hunt HV, Lawes MC, Bower MA, Haeger JW, Howe CJ. A banned variety was the mother of several major wine grapes. Biol Lett 2009; 6:367-9. [PMID: 20015860 DOI: 10.1098/rsbl.2009.0810] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/21/2023] Open
Abstract
A number of widely grown varieties of Vitis vinifera ssp. sativa, the grape used for wine production, are known to have resulted from crosses between Pinot noir and Gouais blanc, although it is not known which was the maternal parent in these crosses. We have analysed microsatellites and a single nucleotide polymorphism (SNP) in chloroplast DNA from these two varieties and twelve progeny strains, including Chardonnay, Gamay noir and Aligoté. The results demonstrate that Gouais blanc was the maternal parent for nine of these strains, including Chardonnay, Gamay noir and Aligoté. This is a striking conclusion, as Gouais is generally considered a highly inferior variety, and its cultivation was banned for many years in parts of Europe.
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Affiliation(s)
- Harriet V Hunt
- McDonald Institute for Archaeological Research, University of Cambridge, Downing Street, Cambridge CB2 3ER, UK
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15
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Meiss E, Konno H, Groth G, Hisabori T. Molecular processes of inhibition and stimulation of ATP synthase caused by the phytotoxin tentoxin. J Biol Chem 2008; 283:24594-9. [PMID: 18579520 DOI: 10.1074/jbc.m802574200] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
F1-ATPase is the smallest mechanical motor known. Tentoxin, a cyclic peptide produced by phytopathogenic fungi, inactivates the F1 motor in sensitive plants at nanomolar to micromolar concentrations, whereas higher concentrations surpass the natural activity of the enzyme. Single molecule studies now have clarified the molecular steps involved in both processes. Inactivation delays the dwell time of a single step in the complete 360 degrees turn and results in an asymmetric rotation of the central rotor subunit. In contrast, rotation in the stimulated F1 particle is smooth and accompanied by strongly reduced ADP inhibition. Our study provides for the first time the direct observation of a noncompetitively inhibited state of the enzyme and directly visualizes the regulation of the molecular motor by an external natural compound. In addition, the ADP release step during catalysis was revealed by analysis of the single molecule rotation behavior. Hence, tentoxin is a sophisticated molecular tool to mark and control certain catalytic steps within the reaction pathway of the molecular F1 motor.
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Affiliation(s)
- Erik Meiss
- Chemical Resources Laboratory, Tokyo Institute of Technology, Nagatsuta 4259-R1-8, Yokohama 226-8503, Japan
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16
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Molecular cloning, characterization and expression of atpA and atpB genes from Ginkgo biloba. Biologia (Bratisl) 2008. [DOI: 10.2478/s11756-008-0093-0] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
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17
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Minoletti C, Santolini J, Haraux F, Pothier J, André F. Rebuilt 3D structure of the chloroplast f1 ATPase-tentoxin complex. Proteins 2002; 49:302-20. [PMID: 12360520 DOI: 10.1002/prot.10137] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
The F1 part of the chloroplast H+ adenosine triphosphate (ATP)-synthase (CF1) strongly interacts with tentoxin, a natural fungous cyclic tetrapeptide known to inhibit the chloroplast enzyme and not the mammalian mitochondrial enzyme. Whereas the synthesis or the hydrolysis of ATP requires the stepwise rotation of the protein rotor gamma within the (alphabeta)3 crown, only one molecule of tentoxin is needed to fully inhibit the complex. With the help of an original homology modeling technique, based on robust distance geometry protocols, we built a tridimensional model of the alpha3beta3gamma CF1) subcomplex (3200 esidues), in which we introduced three different nucleotide occupancies to check their possible influence on the tentoxin binding site. Simultaneous comparison of three available high-resolution X-ray structures of F1, performed with a local structural alignment search tool, led to characterizing common structural blocks and the distorsions experienced by the complex during the catalytic turnover. The common structural blocks were used as a starting point of the spinach CF1 structure rebuilding. Finally, tentoxin was docked into its putative binding site of the reconstructed structure. The docking method was initially validated in the mitochondrial enzyme by its ability to relocate nucleotides into their original position in the crystal. Tentoxin binding was found possible to the two alpha/beta interfaces associated with the empty and adenosine diphosphate (ADP)-loaded catalytic sites, but not to the one associated with the ATP-loaded site. These results suggest a mechanism of CF1 inhibition by one molecule of tentoxin, by the impossibility of the alpha/beta interface bearing tentoxin to pass through the ATP-loaded state.
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Affiliation(s)
- Claire Minoletti
- CNRS URA 2096, Protéines Membranaires Transductrices d'Energie, Section de Bioénergétique, Département de Biologie Cellulaire et Moléculaire, CEA-SACLAY, France
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Groth G, Hisabori T, Lill H, Bald D. Substitution of a single amino acid switches the tentoxin-resistant thermophilic F1-ATPase into a tentoxin-sensitive enzyme. J Biol Chem 2002; 277:20117-9. [PMID: 11943766 DOI: 10.1074/jbc.c200168200] [Citation(s) in RCA: 6] [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
In contrast to the homologous bacterial and mitochondrial enzymes the chloroplast F(1)-ATPase (CF(1)) is strongly affected by the phytopathogenic inhibitor tentoxin. Based on structural information obtained from crystals of a CF(1)-tentoxin co-complex (Groth, G. (2002) Proc. Natl. Acad. Sci. U. S. A. 99, 3464-3468) we have replaced residues betaSer(66) and alphaArg(132) in the alpha(3)beta(3)gamma subcomplex of the thermophilic F(1)-ATPase from Bacillus PS3 by the corresponding residues of the chloroplast ATPase to confer tentoxin sensitivity to the thermophilic enzyme. The mutation alphaArg(132) --> Pro, proposed to relieve steric constraints on tentoxin binding, did not have any significant effect. However, mutation betaSer(66) --> Ala, predicted to provide a crucial hydrogen bond with the inhibitor, resulted in tentoxin inhibition of ATP hydrolysis comparable with the situation found with the chloroplast enzyme.
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Affiliation(s)
- Georg Groth
- Department of Plant Biochemistry, Heinrich-Heine Universitat, D-40225 Dusseldorf, Germany
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Groth G. Structure of spinach chloroplast F1-ATPase complexed with the phytopathogenic inhibitor tentoxin. Proc Natl Acad Sci U S A 2002; 99:3464-8. [PMID: 11904410 PMCID: PMC122546 DOI: 10.1073/pnas.052546099] [Citation(s) in RCA: 41] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/13/2001] [Indexed: 11/18/2022] Open
Abstract
Tentoxin, a natural cyclic tetrapeptide produced by phytopathogenic fungi from the Alternaria species affects the catalytic function of the chloroplast F(1)-ATPase in certain sensitive species of plants. In this study, we show that the uncompetitive inhibitor tentoxin binds to the alphabeta-interface of the chloroplast F(1)-ATPase in a cleft localized at betaAsp-83. Most of the binding site is located on the noncatalytic alpha-subunit. The crystal structure of the tentoxin-inhibited CF(1)-complex suggests that the inhibitor is hydrogen bonded to Asp-83 in the catalytic beta-subunit but forms hydrophobic contacts with residues Ile-63, Leu-65, Val-75, Tyr-237, Leu-238, and Met-274 in the adjacent alpha-subunit. Except for minor changes around the tentoxin-binding site, the structure of the chloroplast alpha(3)beta(3)-core complex is the same as that determined with the native chloroplast ATPase. Tentoxin seems to act by inhibiting inter-subunit contacts at the alphabeta-interface and by blocking the interconversion of binding sites in the catalytic mechanism.
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Affiliation(s)
- Georg Groth
- Heinrich-Heine-Universität, Biochemie der Pflanzen, Universitätsstrasse 1, D-40225 Duesseldorf, Germany.
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Tucker WC, Du Z, Gromet-Elhanan Z, Richter ML. Formation and properties of hybrid photosynthetic F1-ATPases. Demonstration of different structural requirements for stimulation and inhibition by tentoxin. EUROPEAN JOURNAL OF BIOCHEMISTRY 2001; 268:2179-86. [PMID: 11277942 DOI: 10.1046/j.1432-1327.2001.02110.x] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
A hybrid ATPase composed of cloned chloroplast ATP synthase beta and gamma subunits (betaC and gammaC) and the cloned alpha subunit from the Rhodospirillum rubrum ATP synthase (alphaR) was assembled using solubilized inclusion bodies and a simple single-step folding procedure. The catalytic properties of the assembled alpha3Rbeta3CgammaC were compared to those of the core alpha3Cbeta3CgammaC complex of the native chloroplast coupling factor 1 (CF1) and to another recently described hybrid enzyme containing R. rubrum alpha and beta subunits and the CF1 gamma subunit (alpha3Rbeta3RgammaC). All three enzymes were similarly stimulated by dithiothreitol and inhibited by copper chloride in response to reduction and oxidation, respectively, of the disulfide bond in the chloroplast gamma subunit. In addition, all three enzymes exhibited the same concentration dependence for inhibition by the CF1 epsilon subunit. Thus the CF1 gamma subunit conferred full redox regulation and normal epsilon binding to the two hybrid enzymes. Only the native CF1 alpha3Cbeta3CgammaC complex was inhibited by tentoxin, confirming the requirement for both CF1 alpha and beta subunits for tentoxin inhibition. However, the alpha3Rbeta3CgammaC complex, like the alpha3Cbeta3CgammaC complex, was stimulated by tentoxin at concentrations in excess of 10 microm. In addition, replacement of the aspartate at position 83 in betaC with leucine resulted in the loss of stimulation in the alpha3Rbeta3CgammaC hybrid. The results indicate that both inhibition and stimulation by tentoxin require a similar structural contribution from the beta subunit, but differ in their requirements for alpha subunit structure.
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Affiliation(s)
- W C Tucker
- Department of Molecular Biosciences, University of Kansas, Lawrence 66045, USA
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Abstract
The structure of the F(1)-ATPase from spinach chloroplasts was determined to 3.2 A resolution by molecular replacement based on the homologous structure of the bovine mitochondrial enzyme. The crystallized complex contains four different subunits in a stoichiometry of alpha(3)beta(3)gammaepsilon. Subunit delta was removed before crystallization to improve the diffraction of the crystals. The overall structure of the noncatalytic alpha-subunits and the catalytic beta-subunits is highly similar to those of the mitochondrial and thermophilic subunits. However, in the crystal structure of the chloroplast enzyme, all alpha- and beta-subunits adopt a closed conformation and appear to contain no bound adenine nucleotides. The superimposed crystallographic symmetry in the space group R32 impaired an exact tracing of the gamma- and epsilon-subunits in the complex. However, clear electron density was present at the core of the alpha(3)beta(3)-subcomplex, which probably represents the C-terminal domain of the gamma-subunit. The structure of the spinach chloroplast F(1) has a potential binding site for the phytotoxin, tentoxin, at the alphabeta-interface near betaAsp(83) and an insertion from betaGly(56)-Asn(60) in the N-terminal beta-barrel domain probably increases the thermal stability of the complex. The structure probably represents an inactive latent state of the ATPase, which is unique to chloroplast and cyanobacterial enzymes.
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Affiliation(s)
- G Groth
- Heinrich-Heine-Universität, Biochemie der Pflanzen, Universitätsstrasse 1, D-40225 Düsseldorf, Germany and EMBL Hamburg, Notkestrasse 85, D-22603 Hamburg, Germany.
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Tucker WC, Du Z, Hein R, Richter ML, Gromet-Elhanan Z. Hybrid Rhodospirillum rubrum F(0)F(1) ATP synthases containing spinach chloroplast F(1) beta or alpha and beta subunits reveal the essential role of the alpha subunit in ATP synthesis and tentoxin sensitivity. J Biol Chem 2000; 275:906-12. [PMID: 10625626 DOI: 10.1074/jbc.275.2.906] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Trace amounts ( approximately 5%) of the chloroplast alpha subunit were found to be absolutely required for effective restoration of catalytic function to LiCl-treated chromatophores of Rhodospirillum rubrum with the chloroplast beta subunit (Avital, S., and Gromet-Elhanan, Z. (1991) J. Biol. Chem. 266, 7067-7072). To clarify the role of the alpha subunit in the rebinding of beta, restoration of catalytic function, and conferral of sensitivity to the chloroplast-specific inhibitor tentoxin, LiCl-treated chromatophores were analyzed by immunoblotting before and after reconstitution with mixtures of R. rubrum and chloroplast alpha and beta subunits. The treated chromatophores were found to have lost, in addition to most of their beta subunits, approximately a third of the alpha subunits, and restoration of catalytic activity required rebinding of both subunits. The hybrid reconstituted with the R. rubrum alpha and chloroplast beta subunits was active in ATP synthesis as well as hydrolysis, and both activities were completely resistant to tentoxin. In contrast, a hybrid reconstituted with both chloroplast alpha and beta subunits restored only a MgATPase activity, which was fully inhibited by tentoxin. These results indicate that all three copies of the R. rubrum alpha subunit are required for proton-coupled ATP synthesis, whereas for conferral of tentoxin sensitivity at least one copy of the chloroplast alpha subunit is required together with the chloroplast beta subunit. The hybrid system was further used to examine the effects of amino acid substitution at position 83 of the beta subunit on sensitivity to tentoxin.
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Affiliation(s)
- W C Tucker
- Department of Biological Chemistry, Weizmann Institute of Science, Rehovot 76100, Israel
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23
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Du Z, Gromet-Elhanan Z. Refolding of recombinant alpha and beta subunits of the Rhodospirillum rubrum F(0)F(1) ATP synthase into functional monomers that reconstitute an active alpha(1)beta(1)-dimer. EUROPEAN JOURNAL OF BIOCHEMISTRY 1999; 263:430-7. [PMID: 10406951 DOI: 10.1046/j.1432-1327.1999.00512.x] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
The alpha subunit from the Rhodospirillum rubrum F(0)F(1) ATP synthase (RrF(1)alpha) was over-expressed in unc operon-deleted Escherichia coli strains under various growth conditions only in insoluble inclusion bodies. The functional refolding of urea-solubilized RrF(1)alpha was followed by measuring its ability to stimulate the restoration of ATP synthesis and hydrolysis in beta-less R. rubrum chromatophores reconstituted with pure native or recombinant RrF(1)beta [Nathanson, L. & Gromet-Elhanan, Z. (1998) J. Biol. Chem. 273, 10933-10938]. The refolding efficiency was found to increase with decreasing RrF(1)alpha concentrations and required high concentrations of MgATP, saturating approximately 60% when 50 microgram protein.mL(-1) were refolded in presence of 50 mM MgATP. Size-exclusion HPLC of such refolded RrF(1)alpha revealed a 50-60% decrease in its aggregated form and a parallel appearance of its monomeric peak. RrF(1)beta refolded under identical conditions appeared almost exclusively as a monomer. This procedure enabled the isolation of large amounts of a stable RrF(1)alpha monomer, which stimulated the restoration of ATP synthesis and hydrolysis much more efficiently than the refolded alpha mixture, and bound ATP and ADP in a Mg-dependent manner. Incubation of both RrF(1)alpha and beta monomers, which by themselves had no ATPase activity, resulted in a parallel appearance of activity and assembled alpha(1)beta(1)-dimers, but showed no formation of alpha(3)beta(3)-hexamers. The RrF(1)-alpha(1)beta(1)-ATPase activity was, however, very similar to the activity observed in isolated native chloroplast CF(1)-alpha(3)beta(3), indicating that these dimers contain only the catalytic nucleotide-binding site at their alpha/beta interface. Their inability to associate into an alpha(3)beta(3)-hexamer seems therefore to reflect a much lower stability of the noncatalytic RrF(1) alpha/beta interface.
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Affiliation(s)
- Z Du
- Department of Biological Chemistry, The Weizmann Institute of Science, Rehovot, Israel
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24
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Santolini J, Haraux F, Sigalat C, Moal G, André F. Kinetic analysis of tentoxin binding to chloroplast F1-ATPase. A model for the overactivation process. J Biol Chem 1999; 274:849-58. [PMID: 9873024 DOI: 10.1074/jbc.274.2.849] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
The mechanism of action of tentoxin on the soluble part (chloroplast F1 H+-ATPase; CF1) of chloroplast ATP synthase was analyzed in the light of new kinetic and equilibrium experiments. Investigations were done regarding the functional state of the enzyme (activation, bound nucleotide, catalytic turnover). Dialysis and binding data, obtained with 14C-tentoxin, fully confirmed the existence of two tentoxin binding sites of distinct dissociation constants consistent with the observed Kinhibition and Koveractivation. This strongly supports a two-site model of tentoxin action on CF1. Kinetic and thermodynamic parameters of tentoxin binding to the first site (Ki = 10 nM; kon = 4.7 x 10(4) s-1.M-1) were determined from time-resolved activity assays. Tentoxin binding to the high affinity site was found independent on the catalytic state of the enzyme. The analysis of the kinetics of tentoxin binding on the low affinity site of the enzyme showed strong evidence for an interaction between this site and the nucleotide binding sites and revealed a complex relationship between the catalytic state and the reactivation process. New catalytic states of CF1 devoid of epsilon-subunit were detected: a transient overstimulated state, and a dead end complex unable to bind a second tentoxin molecule. Our experiments led to a kinetic model for the reactivation phenomenon for which rate constants were determined. The implications of this model are discussed in relation to the previous mechanistic hypotheses on the effect of tentoxin.
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Affiliation(s)
- J Santolini
- Section de Bioénergétique, Département de Biologie Cellulaire et Moléculaire, Commissariat à l'Energie Atomique-Saclay, F-91191 Gif-sur-Yvette Cedex, France.
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25
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Hippler M, Redding K, Rochaix JD. Chlamydomonas genetics, a tool for the study of bioenergetic pathways. BIOCHIMICA ET BIOPHYSICA ACTA 1998; 1367:1-62. [PMID: 9784589 DOI: 10.1016/s0005-2728(98)00136-4] [Citation(s) in RCA: 56] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Affiliation(s)
- M Hippler
- Departments of Molecular Biology and Plant Biology, University of Geneva, 30 Quai Ernest Ansermet, 1211 Geneva-4, Switzerland
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26
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Nathanson L, Gromet-Elhanan Z. Mutagenesis of beta-Glu-195 of the Rhodospirillum rubrum F1-ATPase and its role in divalent cation-dependent catalysis. J Biol Chem 1998; 273:10933-8. [PMID: 9556571 DOI: 10.1074/jbc.273.18.10933] [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
We introduced mutations at the fully conserved residue Glu-195 in subunit beta of Rhodospirillum rubrum F1-ATPase. The activities of the expressed wild type (WT) and mutant beta subunits were assayed by following their capacity to assemble into the earlier prepared beta-depleted, membrane-bound R. rubrum enzyme (Philosoph, S., Binder, A., and Gromet-Elhanan, Z. (1977) J. Biol. Chem. 252, 8742-8747) and to restore ATP synthesis and/or hydrolysis activity. All three mutations, beta-E195K, beta-E195Q, and beta-E195G, were found to bind as the WTbeta into the beta-depleted enzyme. They restored between 30 and 60% of the WT restored photophosphorylation activity and 16, 45, and 105%, respectively of the CaATPase activity. The mutants required, however, much higher concentrations of divalent cations and could not restore any significant MgATPase or MnATPase activities. Only beta-E195G could restore some of these activities when assayed in the presence of 100 mM sulfite and high MgCl2 or MnCl2 concentrations. These results suggest that the observed difference in restoration of ATP synthesis and CaATPase, as compared with MgATPase and MnATPase, can be due to the tight regulation of the last two activities, resulting in their inhibition at cation/ATP ratios above 0.5. The R. rubrum F1beta-E195 is equivalent to the mitochondrial F1beta-E199, which points into the tunnel leading to the F1 catalytic nucleotide binding sites (Abrahams, J. P., Leslie, A. G. W., Lutter, R., and Walker, J. E. (1994) Nature 370, 621-628). Our findings indicate that this residue, although not an integral part of the F1 catalytic sites, affects divalent cation binding and release of inhibitory MgADP, suggesting its participation in the interconversion of the F1 catalytic sites between different conformational states.
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Affiliation(s)
- L Nathanson
- Department of Biochemistry, The Weizmann Institute of Science, Rehovot 76100, Israel
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Santolini J, Haraux F, Sigalat C, Munier L, André F. Interrelation between high and low affinity tentoxin binding sites in chloroplast F1-ATPase revealed by synthetic analogues. J Biol Chem 1998; 273:3343-50. [PMID: 9452452 DOI: 10.1074/jbc.273.6.3343] [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: 02/06/2023] Open
Abstract
Eight synthetic analogues of tentoxin (cyclo-(L-N-MeGlu1-L-Leu2-N-MeDeltaZPhe3-Gly4)) modified in residues 1, 2, and 3 were checked for their ability to inhibit and reactivate the ATPase activity of the activated soluble part of chloroplast ATP synthase. The data were consistent with a model involving two binding sites of different affinities for the toxins. The occupancy of the high affinity site (or tight site) gave rise to an inactive complex, whereas filling both sites (tight + loose) gave rise to a complex of variable activity, dependent on the toxin analogue. Competition experiments between tentoxin and nonreactivating analogues allowed discrimination between the absence of binding and a nonproductive binding to the site of lower affinity (or loose site). The affinity for the loose site was not affected significantly by the modifications of the tentoxin molecule, whereas the affinity for the tight site was found notably changed. Increasing the size of side chain 1 or 2 and introducing a net electrical charge both resulted in a decrease of affinity for the tight site, but the second change dominated the first one. The activity of different ternary complexes enzyme-tentoxin-analogue depended on the nature of the toxin bound on each site and not only on that bound on the loose site. This demonstrates that the reactivation process results from an interaction, direct or not, between these two binding sites. Possible molecular mechanisms are discussed.
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Affiliation(s)
- J Santolini
- Section de Bioénergétique, Département de Biologie Cellulaire et Moléculaire, CEA-Saclay, bâtiment 532, F-91191 Gif-sur-Yvette Cedex, France
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28
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Affiliation(s)
- W Knogge
- Department of Biochemistry, Max-Planck-Institut für Züchtungsforschung, Cologne, Germany
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Mochimaru M, Sakurai H. Three kinds of binding site for tentoxin on isolated chloroplast coupling factor 1. FEBS Lett 1997; 419:23-6. [PMID: 9426212 DOI: 10.1016/s0014-5793(97)01421-x] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
Tentoxin binding on chloroplast coupling factor 1 (CF1) was studied using a centrifugation column method followed by HPLC analysis. From non-linear regression analysis of the results, the presence of three types of binding site with the following Kd values was deduced: 6.9x10(-8) M (first site), 1.4x10(-5) M (second site), and 6.3x10(-3) M (third site). The binding of one tentoxin inhibits, that of two tentoxins moderately restores, and that of three tentoxins greatly stimulates the ATPase activity of CF1. The forward rate constant of the binding of tentoxin on the first site was 6.3x10(3) M-1 s-1.
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Affiliation(s)
- M Mochimaru
- Department of Biology, School of Education, Waseda University, Tokyo, Japan.
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30
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Delaforge M, Andre F, Jaouen M, Dolgos H, Benech H, Gomis JM, Noel JP, Cavelier F, Verducci J, Aubagnac JL, Liebermann B. Metabolism of tentoxin by hepatic cytochrome P-450 3A isozymes. EUROPEAN JOURNAL OF BIOCHEMISTRY 1997; 250:150-7. [PMID: 9432003 DOI: 10.1111/j.1432-1033.1997.00150.x] [Citation(s) in RCA: 21] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
The interaction between rat and human liver cytochrome P-450 with tentoxin, a natural phytotoxic cyclotetrapeptide having chlorotic properties, was studied by difference ultraviolet visible spectroscopy. Tentoxin interacted with rat liver microsomes and the difference spectrum was characteristic of binding to a protein site close to the heme. The intensity of this spectrum was clearly dependent on the amounts of P-450 3A in the microsomes and was optimal in dexamethasone-treated rat microsomes. Tentoxin exhibited a high affinity for P-450 3A (Ks approximately 10 microM). Similar results were observed with human P-450 isozymes expressed in yeast. Only P-450 3A4 and 3A5 were able to give spectral interactions with tentoxin. Liver microsomes from rats pretreated with dexamethasone, a specific inducer of P-450 3A, were found to be particularly active for the oxidation of tentoxin, which occurs mainly on its Ala(Me) function leading to demethylation. Yeast-expressed P-450 3A also exhibited high activity to metabolize tentoxin. The metabolites were identified by their ultraviolet and mass spectra in fast atom bombardment and collision-activated dissociation modes. In addition to the major N-demethylated metabolite, other hydroxylated metabolites were formed. Preliminary analysis showed that as tentoxin, some metabolites were still efficient chloroplast ATPase inhibitors, while at least one of them exhibited even at low concentration stimulatory effects.
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Affiliation(s)
- M Delaforge
- Université René Descartes, Laboratoire de Chimie et Biochimie Pharmacologiques et Toxicologiques, CNRS URA 400, Paris, France.
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31
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Characterization of atpA and atpB deletion mutants produced in Chlamydomonas reinhardtii cw15: electron transport and photophosphorylation activities of isolated thylakoids. BIOCHIMICA ET BIOPHYSICA ACTA-BIOENERGETICS 1997. [DOI: 10.1016/s0005-2728(96)00123-5] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
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32
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Hu D, Fiedler HR, Golan T, Edelman M, Strotmann H, Shavit N, Leu S. Catalytic properties and sensitivity to tentoxin of Chlamydomonas reinhardtii ATP synthases changed in codon 83 of atpB by site-directed mutagenesis. J Biol Chem 1997; 272:5457-63. [PMID: 9038147 DOI: 10.1074/jbc.272.9.5457] [Citation(s) in RCA: 21] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023] Open
Abstract
The participation of the amino acid beta83 in determining the sensitivity of chloroplast ATP synthases to tentoxin was reported previously. We have changed codon 83 of the Chlamydomonas reinhardtii atpB gene by site-directed mutagenesis to further examine the role of this amino acid in the response of the ATP synthase to tentoxin and in the mechanism of ATP synthesis and hydrolysis. Amino acid beta83 was changed from Glu to Asp (betaE83D) and to Lys (betaE83K), and the highly conserved tetrapeptide betaT82-E83-G84-L85 (DeltaTEGL) was deleted. Mutant strains were produced by particle gun transformation of atpB deletion mutants cw15DeltaatpB and FUD50 with the mutated atpB genes. The transformants containing the betaE83D and betaE83K mutant genes grew well photoautotrophically. The DeltaTEGL transformant did not grow photoautotrophically, and no CF1 subunits were detected by immunostaining of Western blots using CF1 specific antibodies. The rates of ATP synthesis at clamped DeltapH with thylakoids isolated from cw15 and the two mutants, betaE83D and betaE83K, were similar. However, only the phosphorylation activity of the mutant betaE83D was inhibited by tentoxin with 50% inhibition attained at 4 microM. These results confirm that amino acid beta83 is critical in determining the response of ATP synthase to tentoxin. The rates of the latent Mg-ATPase activity of the CF1s isolated from cw15, betaE83D, and betaE83K were similar and could be enhanced by heat, alcohols, and octylglucoside. As in the case of the membrane-bound enzyme, only CF1 from the betaE83D mutant was sensitive to tentoxin. A lower alcohol concentration was required for optimal stimulation of the ATPase of the betaE83K-CF1 than that of CF1 from the other two strains. Moreover, the optimal activity of the betaE83K-CF1 was also lower. These results suggest that introduction of an amino acid with a positively charged side chain in position 83 in the "crown" domain affects the active conformation of the CF1-ATPase.
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Affiliation(s)
- D Hu
- Doris and Bertie Black Center for Bioenergetics in Life Sciences, Ben Gurion University of the Negev, Beer Sheva 84105, Israel
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33
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Etzold C, Deckers-Hebestreit G, Altendorf K. Turnover number of Escherichia coli F0F1 ATP synthase for ATP synthesis in membrane vesicles. EUROPEAN JOURNAL OF BIOCHEMISTRY 1997; 243:336-43. [PMID: 9030757 DOI: 10.1111/j.1432-1033.1997.0336a.x] [Citation(s) in RCA: 53] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
Abstract
The rate of ATP synthesized by the ATP synthase (F0F1-ATPase) is limited by the rate of energy production via the respiratory chain, when measured in everted membrane vesicles of an Escherichia coli atp wild-type strain. After energization of the membranes with NADH, fractional inactivation of F0F1 by the covalent inhibitor N,N'-dicyclohexylcarbodiimide allowed the rate of ATP synthesis/mol remaining active ATP synthase complexes to increase; the active ATP synthase complexes were calculated using ATP hydrolysis rates as the defining parameter. In addition, variation of the assay temperature revealed an increase of the ATP synthesis rate up to a temperature of 37 degrees C, the optimal growth temperature of E. coli. In parallel, the amount of F0F1 complexes present in membrane vesicles was determined by immunoquantitation to be 3.3 +/- 0.3% of the membrane protein for cells grown in rich medium and 6.6 +/- 0.3% for cells grown in minimal medium with glycerol as sole carbon and energy source. Based on these data, a turnover number for ATP synthesis of 270 +/- 40 s(-1) could be determined in the presence of 5% active F0F1 complexes. Therefore, these studies demonstrate that the ATP synthase complex of E. coli has, with respect to maximum rates, the same capacity as the corresponding enzymes of eukaryotic organells.
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Affiliation(s)
- C Etzold
- Fachbereich Biologie/Chemie, Arbeitsgruppe Mikrobiologie, Universitat Osnabruck, Germany
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34
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Pinet E, Gomis JM, Girault G, Cavelier F, Verducci J, Noël JP, André F. Tentoxin has at least two binding sites on CF1 and epsilon-depleted CF1 ATPases isolated from spinach chloroplast. FEBS Lett 1996; 395:217-20. [PMID: 8898099 DOI: 10.1016/0014-5793(96)01043-5] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
Abstract
A new procedure for synthesis of 14C-labeled tentoxin [14C-MePhe[(Z)delta]3-tentoxin], with a high specific activity, is described. Binding experiments with CF1 or CF1-epsilon isolated from spinach chloroplast have been carried out using equilibrium dialysis technique. The results show the presence of two classes of binding sites. The association constants of the two major binding sites were derived from non-linear fitting of the binding curves. At 4 degrees C, the first binding site has a value of Ka1 = 8.2 x 10(5) M(-1) in CF1 and 8.7 x 10(5) M(-1) in CF1-epsilon, while the second binding site has lower affinity with Ka2 = 1.5 x 10(4) M(-1) in CF1 and 2.3 x 10(3) M(-1) in CF1-epsilon.
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Affiliation(s)
- E Pinet
- Département de Biologie Cellulaire et Moléculaire, CEA-Saclay, Gif-sur-Yvette, France
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The ATP synthase of Streptomyces lividans: characterization and purification of the F1Fo complex. BIOCHIMICA ET BIOPHYSICA ACTA-BIOENERGETICS 1996. [DOI: 10.1016/0005-2728(96)00003-5] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
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36
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Pinet E, Neumann JM, Dahse I, Girault G, André F. Multiple interconverting conformers of the cyclic tetrapeptide tentoxin, [cyclo-(L-MeAla1-L-Leu2-MePhe[(Z) delta]3-Gly4)], as seen by two-dimensional 1H-nmr spectroscopy. Biopolymers 1995; 36:135-52. [PMID: 7492742 DOI: 10.1002/bip.360360204] [Citation(s) in RCA: 25] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/25/2023]
Abstract
The conformations of the phytotoxic cyclic tetrapeptide tentoxin [cyclo-(L-MeAla1-L-Leu2-MePhe[(Z) delta]3-Gly4)] have been studied in aqueous solution by two-dimensional proton nmr at various temperatures. Contrary to what is observed in chloroform, tentoxin exhibits multiple exchanging conformations in water. Aggregation phenomena were also observed. Four conformations with different proportions (51, 37, 8, and 4%) were observed at -5 degrees C. Models were constructed from nmr parameters and restrained molecular dynamics simulations. All the models exhibit cis-trans-cis-trans conformation of the amide bond sequence. The conversion from one form to another is accomplished by a conformational peptide flip consisting of a 180 degree rotation of a nonmethylated peptide bond.
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Affiliation(s)
- E Pinet
- Département de Biologie Cellulaire et Moléculaire, CEA-Saclay Gif-sur-Yvette, France
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37
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Chen Z, Spies A, Hein R, Zhou X, Thomas BC, Richter ML, Gegenheimer P. A subunit interaction in chloroplast ATP synthase determined by genetic complementation between chloroplast and bacterial ATP synthase genes. J Biol Chem 1995; 270:17124-32. [PMID: 7615507 DOI: 10.1074/jbc.270.29.17124] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023] Open
Abstract
F1F0-ATP synthases utilize protein conformational changes induced by a transmembrane proton gradient to synthesize ATP. The allosteric cooperativity of these multisubunit enzymes presumably requires numerous protein-protein interactions within the enzyme complex. To correlate known in vitro changes in subunit structure with in vivo allosteric interactions, we introduced the beta subunit of spinach chloroplast coupling factor 1 ATP into a bacterial F1 ATP synthase. A cloned atpB gene, encoding the complete chloroplast beta subunit, complemented a chromosomal deletion of the cognate uncD gene in Escherichia coli and was incorporated into a functional hybrid F1 ATP synthase. The cysteine residue at position 63 in chloroplast beta is known to be located at the interface between alpha and beta subunits and to be conformationally coupled, in vitro, to the nucleotide binding site > 40 A away. Enlarging the side chain of chloroplast coupling factor 1 beta residue 63 from Cys to Trp blocked ATP synthesis in vivo without significantly impairing ATPase activity or ADP binding in vitro. The in vivo coupling of nucleotide binding at catalytic sites to transmembrane proton movement may thus involve an interaction, via conformational changes, between the amino-terminal domains of the alpha and beta subunits.
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Affiliation(s)
- Z Chen
- Department of Biochemistry, University of Kansas, Lawrence 66045-2106, USA
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38
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Sigalat C, Pitard B, Haraux F. Proton coupling is preserved in membrane-bound chloroplast ATPase activated by high concentrations of tentoxin. FEBS Lett 1995; 368:253-6. [PMID: 7628616 DOI: 10.1016/0014-5793(95)00664-u] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
Abstract
The effect of tentoxin at high concentrations was investigated in thylakoids and proteoliposomes containing bacteriorhodopsin and CF0CF1. Venturicidin-sensitive ATP hydrolysis, ATP-generated delta pH and ATP synthesis were practically 100% inhibited at 2 microM tentoxin, and restored to various extents beyond 50 microM. With respect to the native enzyme, tentoxin-reactivated ATPase had the following properties: (i) a higher delta pH requirement to synthetise ATP; (ii) a decreased futile proton flow through CF0CF1 (without ADP), which remains 100% blocked by ADP. It is concluded that despite its altered kinetic performances, tentoxin-modified CF0CF1 preserves its mechanism and remains a tightly coupled proton pump.
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Affiliation(s)
- C Sigalat
- Section de Bioénergétique, DBCM-CEA Saclay, Gif-sur-Yvette, France
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39
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Webber AN, Bingham SE, Lee H. Genetic engineering of thylakoid protein complexes by chloroplast transformation in Chlamydomonas reinhardtii. PHOTOSYNTHESIS RESEARCH 1995; 44:191-205. [PMID: 24307038 DOI: 10.1007/bf00018309] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/20/1994] [Accepted: 03/01/1995] [Indexed: 06/02/2023]
Abstract
Chloroplast transformation of Chlamydomonas reinhardtii has developed into a powerful tool for studying the structure, function and assembly of thylakoid protein complexes in a eukaryotic organism. In this article we review the progress that is being made in the development of procedures for efficient chloroplast transformation. This focuses on the development of selectable markers and the use of Chlamydomonas mutants, individually lacking thylakoid protein complexes, as recipients. Chloroplast transformation has now been used to engineer all four major thylakoid protein complexes, photosystem II, photosystem I, cytochrome b 6/f and ATP synthase. These results are discussed with an emphasis on new insights into assembly and function of these complexes in chloroplasts as compared with their prokaryotic counterparts.
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Affiliation(s)
- A N Webber
- Department of Botany and Center for the Study of Early Events in Photosynthesis, Arizona State University, Box 871601, 85287-1601, Tempe, AZ, USA
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40
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Gao F, Lipscomb B, Wu I, Richter ML. In vitro assembly of the core catalytic complex of the chloroplast ATP synthase. J Biol Chem 1995; 270:9763-9. [PMID: 7730354 DOI: 10.1074/jbc.270.17.9763] [Citation(s) in RCA: 25] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023] Open
Abstract
The regulatory gamma subunit and an alpha beta complex were isolated from the catalytic F1 portion of the chloroplast ATP synthase. The isolated gamma subunit was devoid of catalytic activity, whereas the alpha beta complex exhibited a very low ATPase activity (approximately 200 nmol/min/mg of protein). The alpha beta complex migrated as a hexameric alpha 3 beta 3 complex during ultracentrifugation and gel filtration but reversibly dissociated into alpha and beta monomers after freezing and thawing in the presence of ethylenediamine tetraacetic acid and in the absence of nucleotides. Conditions are described in which the gamma and alpha beta preparations were combined to rapidly and efficiently reconstitute a fully functional catalytic core enzyme complex. The reconstituted enzyme exhibited normal tight binding and sensitivity to the inhibitory epsilon subunit and to the allosteric inhibitor tentoxin. However, neither the alpha beta complex nor the isolated gamma subunit alone could bind the epsilon subunit or tentoxin with high affinity. Similarly, high affinity binding sites for ATP and ADP, which are characteristic of the core alpha 3 beta 3 gamma enzyme, were absent from the alpha beta complex. The results indicate that when the gamma subunit binds to the alpha beta complex, it induces a three-dimensional conformation in the enzyme, which is necessary for tight binding of the inhibitors and for high-affinity, asymmetric nucleotide binding.
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Affiliation(s)
- F Gao
- Department of Biochemistry, University of Kansas, Lawrence 66045, USA
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41
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Abstract
ATP synthase (F-ATPase) of chloroplasts, CF0CF1, is both activated and driven by transmembrane protonmotive force. We dichotomized between activating and driving proton transfer by specific inhibitors, tentoxin and venturicidin. Thylakoids membranes were submitted to voltage steps (by flashing light) superimposed to a steady pH-difference. Transient proton intake, transfer and release by CF0CF1 was monitored by spectroscopic probes. Both activities, activation and catalysis, required all three partial reactions of the proton, however, activating proton transfer rose first (monophasically, tau 1/2 approximately 15 ms) followed by another phase of equal magnitude with a time lag of about 15 ms. Both types of consecutive proton transfer reactions contribute free energy for ATP synthesis.
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Affiliation(s)
- G Groth
- Abt. Biophysik, Universität Osnabrück, Germany
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42
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Chen GG, Jagendorf AT. Chloroplast molecular chaperone-assisted refolding and reconstitution of an active multisubunit coupling factor CF1 core. Proc Natl Acad Sci U S A 1994; 91:11497-501. [PMID: 7972091 PMCID: PMC45258 DOI: 10.1073/pnas.91.24.11497] [Citation(s) in RCA: 34] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023] Open
Abstract
The chloroplast coupling factor 1 (CF1) is composed of five kinds of subunits with a stoichiometry of alpha 3 beta 3 gamma delta epsilon. Reconstitution of a catalytically active alpha 3 beta 3 gamma core from urea-denatured subunits at a physiological pH is reported here. A restoration of approximately 90% of the CF1 ATPase activity has been observed. The reconstitution was achieved by using subunits overexpressed in Escherichia coli, purified, and combined in the presence of MgATP, K+, and a mixture of several chloroplast molecular chaperones at pH 7.5. The combination of chaperonin 60 and chaperonin 24 failed to reconstitute the active CF1 core, as did the GroEL/GroES pair (E. coli chaperonin 60/10 homologues). Characteristics of the reconstituted ATPase were very close to those of the native complex, including methanol-reversible inhibition by the purified epsilon subunit of CF1 and sensitivity to inhibition by azide and by tentoxin. In reconstitution with a mixture of tentoxin-resistant and -sensitive beta subunits, the extent of inhibition by tentoxin depended on the proportion of sensitive subunits in the reconstitution mixture. Finally, a model for the assembly of the CF1 core alpha 3 beta 3 gamma structure is proposed.
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Affiliation(s)
- G G Chen
- Section of Plant Biology, Cornell University, Ithaca, NY 14853
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43
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Carrer H, Hockenberry TN, Svab Z, Maliga P. Kanamycin resistance as a selectable marker for plastid transformation in tobacco. MOLECULAR & GENERAL GENETICS : MGG 1993; 241:49-56. [PMID: 8232211 DOI: 10.1007/bf00280200] [Citation(s) in RCA: 99] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/29/2023]
Abstract
We report on a novel chimeric gene that confers kanamycin resistance on tobacco plastids. The kan gene from the bacterial transposon Tn5, encoding neomycin phosphotransferase (NPTII), was placed under control of plastid expression signals and cloned between rbcL and ORF512 plastid gene sequences to target the insertion of the chimeric gene into the plastid genome. Transforming plasmid pTNH32 DNA was introduced into tobacco leaves by the biolistic procedure, and plastid transformants were selected by their resistance to 50 micrograms/ml of kanamycin monosulfate. The regenerated plants uniformly transmitted the transplastome to the maternal progeny. Resistant clones resulting from incorporation of the chimeric gene into the nuclear genome were also obtained. However, most of these could be eliminated by screening for resistance to high levels of kanamycin (500 micrograms/ml). Incorporation of kan into the plastid genome led to its amplification to a high copy number, about 10,000 per leaf cell, and accumulation of NPTII to about 1% of total cellular protein.
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Affiliation(s)
- H Carrer
- Waksman Institute, Rutgers, State University of New Jersey, Piscataway 08855-0759
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44
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Hu N, Mills D, Huchzermeyer B, Richter M. Inhibition by tentoxin of cooperativity among nucleotide binding sites on chloroplast coupling factor 1. J Biol Chem 1993. [DOI: 10.1016/s0021-9258(18)52908-2] [Citation(s) in RCA: 34] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022] Open
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45
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Chen G, Jagendorf A. Import and assembly of the beta-subunit of chloroplast coupling factor 1 (CF1) into isolated intact chloroplasts. J Biol Chem 1993. [DOI: 10.1016/s0021-9258(18)53784-4] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022] Open
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