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Busby JN, Trevelyan S, Pegg CL, Kerr ED, Schulz BL, Chassagnon I, Landsberg MJ, Weston MK, Hurst MRH, Lott JS. The ABC toxin complex from Yersinia entomophaga can package three different cytotoxic components expressed from distinct genetic loci in an unfolded state: the structures of both shell and cargo. IUCRJ 2024; 11:299-308. [PMID: 38512773 PMCID: PMC11067744 DOI: 10.1107/s2052252524001969] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/24/2023] [Accepted: 02/28/2024] [Indexed: 03/23/2024]
Abstract
Bacterial ABC toxin complexes (Tcs) comprise three core proteins: TcA, TcB and TcC. The TcA protein forms a pentameric assembly that attaches to the surface of target cells and penetrates the cell membrane. The TcB and TcC proteins assemble as a heterodimeric TcB-TcC subcomplex that makes a hollow shell. This TcB-TcC subcomplex self-cleaves and encapsulates within the shell a cytotoxic `cargo' encoded by the C-terminal region of the TcC protein. Here, we describe the structure of a previously uncharacterized TcC protein from Yersinia entomophaga, encoded by a gene at a distant genomic location from the genes encoding the rest of the toxin complex, in complex with the TcB protein. When encapsulated within the TcB-TcC shell, the C-terminal toxin adopts an unfolded and disordered state, with limited areas of local order stabilized by the chaperone-like inner surface of the shell. We also determined the structure of the toxin cargo alone and show that when not encapsulated within the shell, it adopts an ADP-ribosyltransferase fold most similar to the catalytic domain of the SpvB toxin from Salmonella typhimurium. Our structural analysis points to a likely mechanism whereby the toxin acts directly on actin, modifying it in a way that prevents normal polymerization.
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Affiliation(s)
- Jason N. Busby
- School of Biological Sciences, University of Auckland, Auckland 1142, New Zealand
| | - Sarah Trevelyan
- School of Biological Sciences, University of Auckland, Auckland 1142, New Zealand
| | - Cassandra L. Pegg
- School of Chemistry and Molecular Biosciences, University of Central Queensland, Brisbane, Queensland 4072, Australia
| | - Edward D. Kerr
- School of Chemistry and Molecular Biosciences, University of Central Queensland, Brisbane, Queensland 4072, Australia
| | - Benjamin L. Schulz
- School of Chemistry and Molecular Biosciences, University of Central Queensland, Brisbane, Queensland 4072, Australia
| | - Irene Chassagnon
- School of Chemistry and Molecular Biosciences, University of Central Queensland, Brisbane, Queensland 4072, Australia
| | - Michael J. Landsberg
- School of Chemistry and Molecular Biosciences, University of Central Queensland, Brisbane, Queensland 4072, Australia
| | - Mitchell K. Weston
- Resilient Agriculture, AgResearch, Lincoln Research Centre, Christchurch 8140, New Zealand
| | - Mark R. H. Hurst
- Resilient Agriculture, AgResearch, Lincoln Research Centre, Christchurch 8140, New Zealand
| | - J. Shaun Lott
- School of Biological Sciences, University of Auckland, Auckland 1142, New Zealand
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Han X, Huang C, Qi H, Zhu Y, Hu X, Wen Y, Long Y, Xu L, Zhang F. The construction and evaluation of secretory expression engineering bacteria for the trans-Cry3Aa-T-HasA fusion protein against the Monochamus alternatus vector. Front Cell Infect Microbiol 2024; 14:1362961. [PMID: 38465234 PMCID: PMC10921938 DOI: 10.3389/fcimb.2024.1362961] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/29/2023] [Accepted: 02/06/2024] [Indexed: 03/12/2024] Open
Abstract
Pine wood nematode disease is currently the most deadly forest disease in China, and the Monochamus alternatus is its primary vector. Controlling the M. alternatus is crucial for managing pine wood nematode disease. This study, based on the selected HasA (pGHKW4) secretory expression vector, used electroporation to combine the genetically modified high-toxicity toxin Cry3Aa-T with the entomopathogenic bacterium Yersinia entomophaga isolated from the gut of the M. alternatus. The SDS-PAGE and Western blotting techniques were employed to confirm the toxin protein's secretion capability. The engineered bacteria's genetic stability and effectiveness in controlling M. alternatus were assessed for their insecticidal activity. The results of the SDS-PAGE and Western blotting analyses indicate that the HasA system effectively expresses toxin protein secretion, demonstrates certain genetic stability, and exhibits high insecticidal activity against M. alternatus. This study constructed a highly toxic entomopathogenic engineered bacterial strain against M. alternatus larvae, which holds significant implications for controlling M. alternatus, laying the foundation for subsequent research and application of this strain.
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Affiliation(s)
- Xiaohong Han
- College of Forestry, Fujian Agriculture and Forestry University, Fuzhou, China
- Key Laboratory of Integrated Pest Management in Ecological Forests, Fujian Province University, Fujian Agriculture and Forestry University, Fuzhou, China
| | - Chenyan Huang
- State Key Laboratory of Biocontrol, School of Ecology, Sun Yat-sen University, Guangzhou, China
| | - Huan Qi
- College of Forestry, Fujian Agriculture and Forestry University, Fuzhou, China
- Key Laboratory of Integrated Pest Management in Ecological Forests, Fujian Province University, Fujian Agriculture and Forestry University, Fuzhou, China
| | - Yukun Zhu
- College of Forestry, Fujian Agriculture and Forestry University, Fuzhou, China
- Key Laboratory of Integrated Pest Management in Ecological Forests, Fujian Province University, Fujian Agriculture and Forestry University, Fuzhou, China
| | - Xinran Hu
- College of Forestry, Fujian Agriculture and Forestry University, Fuzhou, China
- Key Laboratory of Integrated Pest Management in Ecological Forests, Fujian Province University, Fujian Agriculture and Forestry University, Fuzhou, China
| | - Yingxin Wen
- College of Forestry, Fujian Agriculture and Forestry University, Fuzhou, China
- Key Laboratory of Integrated Pest Management in Ecological Forests, Fujian Province University, Fujian Agriculture and Forestry University, Fuzhou, China
| | - Yirong Long
- College of Forestry, Fujian Agriculture and Forestry University, Fuzhou, China
- Key Laboratory of Integrated Pest Management in Ecological Forests, Fujian Province University, Fujian Agriculture and Forestry University, Fuzhou, China
| | - Lei Xu
- Graduate School of Chinese Academy of Agricultural Sciences, Beijing, China
| | - Feiping Zhang
- College of Forestry, Fujian Agriculture and Forestry University, Fuzhou, China
- Key Laboratory of Integrated Pest Management in Ecological Forests, Fujian Province University, Fujian Agriculture and Forestry University, Fuzhou, China
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Palma L, Frizzo L, Kaiser S, Berry C, Caballero P, Bode HB, Del Valle EE. Genome Sequence Analysis of Native Xenorhabdus Strains Isolated from Entomopathogenic Nematodes in Argentina. Toxins (Basel) 2024; 16:108. [PMID: 38393187 PMCID: PMC10892061 DOI: 10.3390/toxins16020108] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/02/2024] [Revised: 02/05/2024] [Accepted: 02/13/2024] [Indexed: 02/25/2024] Open
Abstract
Entomopathogenic nematodes from the genus Steinernema (Nematoda: Steinernematidae) are capable of causing the rapid killing of insect hosts, facilitated by their association with symbiotic Gram-negative bacteria in the genus Xenorhabdus (Enterobacterales: Morganellaceae), positioning them as interesting candidate tools for the control of insect pests. In spite of this, only a limited number of species from this bacterial genus have been identified from their nematode hosts and their insecticidal properties documented. This study aimed to perform the genome sequence analysis of fourteen Xenorhabdus strains that were isolated from Steinernema nematodes in Argentina. All of the strains were found to be able of killing 7th instar larvae of Galleria mellonella (L.) (Lepidoptera: Pyralidae). Their sequenced genomes harbour 110 putative insecticidal proteins including Tc, Txp, Mcf, Pra/Prb and App homologs, plus other virulence factors such as putative nematocidal proteins, chitinases and secondary metabolite gene clusters for the synthesis of different bioactive compounds. Maximum-likelihood phylogenetic analysis plus average nucleotide identity calculations strongly suggested that three strains should be considered novel species. The species name for strains PSL and Reich (same species according to % ANI) is proposed as Xenorhabdus littoralis sp. nov., whereas strain 12 is proposed as Xenorhabdus santafensis sp. nov. In this work, we present a dual insight into the biocidal potential and diversity of the Xenorhabdus genus, demonstrated by different numbers of putative insecticidal genes and biosynthetic gene clusters, along with a fresh exploration of the species within this genus.
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Affiliation(s)
- Leopoldo Palma
- Instituto de Biotecnología y Biomedicina (BIOTECMED), Departamento de Genética, Universitat de València, 46100 Burjassot, Spain
- Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), Ciudad Autónoma de Buenos Aires C1033AAJ, Argentina
- Instituto Multidisciplinario de Investigación y Transferencia Agroalimentaria y Biotecnológica (IMITAB), Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), Universidad Nacional de Villa María (UNVM), Villa María 1555, Argentina
| | - Laureano Frizzo
- ICIVET Litoral, CONICET-UNL, Departamento de Salud Pública, Facultad de Ciencias Veterinarias, Universidad Nacional del Litoral, Esperanza S3080, Argentina;
| | - Sebastian Kaiser
- Department of Natural Products in Organismic Interactions, Max-Planck-Institute for Terrestrial Microbiology, 35043 Marburg, Germany; (S.K.); (H.B.B.)
- Evolutionary Biochemistry Group, Max-Planck-Institute for Terrestrial Microbiology, 35043 Marburg, Germany
| | - Colin Berry
- Cardiff School of Biosciences, Cardiff University, Museum Avenue, Cardiff CF10 3AX, UK;
| | - Primitivo Caballero
- Institute for Multidisciplinary Research in Applied Biology, Universidad Pública de Navarra, 31006 Pamplona, Spain;
- Departamento de Investigación y Desarrollo, Bioinsectis SL, Polígono Industrial Mocholi Plaza Cein 5, Nave A14, 31110 Noain, Spain
| | - Helge B. Bode
- Department of Natural Products in Organismic Interactions, Max-Planck-Institute for Terrestrial Microbiology, 35043 Marburg, Germany; (S.K.); (H.B.B.)
- Molecular Biotechnology, Department of Biosciences, Goethe Universität Frankfurt, 60438 Frankfurt, Germany
- Center for Synthetic Microbiology (SYNMIKRO), Phillips University Marburg, 35043 Marburg, Germany
- Department of Chemistry, Phillips University Marburg, 35043 Marburg, Germany
- Senckenberg Gesellschaft für Naturforschung, 60325 Frankfurt, Germany
| | - Eleodoro Eduardo Del Valle
- ICiagro Litoral, CONICET, Facultad de Ciencias Agrarias, Universidad Nacional del Litoral, Kreder 2805, Esperanza S3080, Argentina
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Feldmüller M, Ericson CF, Afanasyev P, Lien YW, Weiss GL, Wollweber F, Schoof M, Hurst M, Pilhofer M. Stepwise assembly and release of Tc toxins from Yersinia entomophaga. Nat Microbiol 2024; 9:405-420. [PMID: 38316932 PMCID: PMC10847046 DOI: 10.1038/s41564-024-01611-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/08/2023] [Accepted: 01/17/2024] [Indexed: 02/07/2024]
Abstract
Tc toxins are virulence factors of bacterial pathogens. Although their structure and intoxication mechanism are well understood, it remains elusive where this large macromolecular complex is assembled and how it is released. Here we show by an integrative multiscale imaging approach that Yersinia entomophaga Tc (YenTc) toxin components are expressed only in a subpopulation of cells that are 'primed' with several other potential virulence factors, including filaments of the protease M66/StcE. A phage-like lysis cassette is required for YenTc release; however, before resulting in complete cell lysis, the lysis cassette generates intermediate 'ghost' cells, which may serve as assembly compartments and become packed with assembled YenTc holotoxins. We hypothesize that this stepwise mechanism evolved to minimize the number of cells that need to be killed. The occurrence of similar lysis cassettes in diverse organisms indicates a conserved mechanism for Tc toxin release that may apply to other extracellular macromolecular machines.
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Affiliation(s)
- Miki Feldmüller
- Department of Biology, Institute of Molecular Biology and Biophysics, Eidgenössische Technische Hochschule Zürich, Zürich, Switzerland
| | - Charles F Ericson
- Department of Biology, Institute of Molecular Biology and Biophysics, Eidgenössische Technische Hochschule Zürich, Zürich, Switzerland
| | | | - Yun-Wei Lien
- Department of Biology, Institute of Molecular Biology and Biophysics, Eidgenössische Technische Hochschule Zürich, Zürich, Switzerland
| | - Gregor L Weiss
- Department of Biology, Institute of Molecular Biology and Biophysics, Eidgenössische Technische Hochschule Zürich, Zürich, Switzerland
| | - Florian Wollweber
- Department of Biology, Institute of Molecular Biology and Biophysics, Eidgenössische Technische Hochschule Zürich, Zürich, Switzerland
| | - Marion Schoof
- Bio-Protection Research Centre, Lincoln University, Lincoln, Christchurch, New Zealand
- AgResearch, Resilient Agriculture, Lincoln Research Centre, Christchurch, New Zealand
| | - Mark Hurst
- Bio-Protection Research Centre, Lincoln University, Lincoln, Christchurch, New Zealand
- AgResearch, Resilient Agriculture, Lincoln Research Centre, Christchurch, New Zealand
| | - Martin Pilhofer
- Department of Biology, Institute of Molecular Biology and Biophysics, Eidgenössische Technische Hochschule Zürich, Zürich, Switzerland.
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5
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Sitsel O, Wang Z, Janning P, Kroczek L, Wagner T, Raunser S. Yersinia entomophaga Tc toxin is released by T10SS-dependent lysis of specialized cell subpopulations. Nat Microbiol 2024; 9:390-404. [PMID: 38238469 PMCID: PMC10847048 DOI: 10.1038/s41564-023-01571-z] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/28/2023] [Accepted: 11/29/2023] [Indexed: 02/04/2024]
Abstract
Disease-causing bacteria secrete numerous toxins to invade and subjugate their hosts. Unlike many smaller toxins, the secretion machinery of most large toxins remains enigmatic. By combining genomic editing, proteomic profiling and cryo-electron tomography of the insect pathogen Yersinia entomophaga, we demonstrate that a specialized subset of these cells produces a complex toxin cocktail, including the nearly ribosome-sized Tc toxin YenTc, which is subsequently exported by controlled cell lysis using a transcriptionally coupled, pH-dependent type 10 secretion system (T10SS). Our results dissect the Tc toxin export process by a T10SS, identifying that T10SSs operate via a previously unknown lytic mode of action and establishing them as crucial players in the size-insensitive release of cytoplasmically folded toxins. With T10SSs directly embedded in Tc toxin operons of major pathogens, we anticipate that our findings may model an important aspect of pathogenesis in bacteria with substantial impact on agriculture and healthcare.
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Affiliation(s)
- Oleg Sitsel
- Department of Structural Biochemistry, Max Planck Institute of Molecular Physiology, Dortmund, Germany
| | - Zhexin Wang
- Department of Structural Biochemistry, Max Planck Institute of Molecular Physiology, Dortmund, Germany
| | - Petra Janning
- Department of Chemical Biology, Max Planck Institute of Molecular Physiology, Dortmund, Germany
| | - Lara Kroczek
- Department of Structural Biochemistry, Max Planck Institute of Molecular Physiology, Dortmund, Germany
| | - Thorsten Wagner
- Department of Structural Biochemistry, Max Planck Institute of Molecular Physiology, Dortmund, Germany
| | - Stefan Raunser
- Department of Structural Biochemistry, Max Planck Institute of Molecular Physiology, Dortmund, Germany.
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6
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Sänger PA, Knüpfer M, Kegel M, Spanier B, Liebler-Tenorio EM, Fuchs TM. Regulation and Functionality of a Holin/Endolysin Pair Involved in Killing of Galleria mellonella and Caenorhabditis elegans by Yersinia enterocolitica. Appl Environ Microbiol 2023; 89:e0003623. [PMID: 37184385 PMCID: PMC10304863 DOI: 10.1128/aem.00036-23] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/12/2023] [Accepted: 03/30/2023] [Indexed: 05/16/2023] Open
Abstract
The insecticidal toxin complex (Tc) proteins are produced by several insect-associated bacteria, including Yersinia enterocolitica strain W22703, which oscillates between two distinct pathogenicity phases in invertebrates and humans. The mechanism by which this high-molecular-weight toxin is released into the extracellular surrounding, however, has not been deciphered. In this study, we investigated the regulation and functionality of a phage-related holin/endolysin (HE) cassette located within the insecticidal pathogenicity island Tc-PAIYe of W22703. Using the Galleria mellonella infection model and luciferase reporter fusions, we revealed that quorum sensing contributes to the insecticidal activity of W22703 upon influencing the transcription of tcaR2, which encodes an activator of the tc and HE genes. In contrast, a lack of the Yersinia modulator, YmoA, stimulated HE gene transcription, and mutant W22703 ΔymoA exhibited a stronger toxicity toward insect larvae than did W22703. A luciferase reporter fusion demonstrated transcriptional activation of the HE cassette in vivo, and a significantly larger extracellular amount of subunit TcaA was found in W22703 ΔymoA relative to its ΔHE mutant. Using competitive growth assays, we demonstrated that at least in vitro, the TcaA release upon HE activity is not mediated by cell lysis of a significant part of the population. Oral infection of Caenorhabditis elegans with a HE deletion mutant attenuated the nematocidal activity of the wild type, similar to the case with a mutant lacking a Tc subunit. We conclude that the dual holin/endolysin cassette of yersiniae is a novel example of a phage-related function adapted for the release of a bacterial toxin. IMPORTANCE Members of the genus Yersinia cause gastroenteritis in humans but also exhibit toxicity toward invertebrates. A virulence factor required for this environmental life cycle stage is the multisubunit toxin complex (Tc), which is distinct from the insecticidal toxin of Bacillus thuringiensis and has the potential to be used in pest control. The mechanism by which this high-molecular-weight Tc is secreted from bacterial cells has not been uncovered. Here, we show that a highly conserved phage-related holin/endolysin pair, which is encoded by the genes holY and elyY located between the Tc subunit genes, is essential for the insecticidal activity of Y. enterocolitica and that its activation increases the amount of Tc subunits in the supernatant. Thus, the dual holY-elyY cassette of Y. enterocolitica constitutes a new example for a type 10 secretion system to release bacterial toxins.
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Affiliation(s)
| | - Mandy Knüpfer
- Chair for Microbial Ecology, Institute for Food and Health (ZIEL), TUM School of Life Sciences, Technische Universität München, Freising, Germany
| | - Marcel Kegel
- Chair for Microbial Ecology, Institute for Food and Health (ZIEL), TUM School of Life Sciences, Technische Universität München, Freising, Germany
| | - Britta Spanier
- Chair for Metabolic Programming, Institute for Food and Health (ZIEL), TUM School of Life Sciences, Technische Universität München, Freising, Germany
| | | | - Thilo M. Fuchs
- Friedrich-Loeffler-Institut, Institute of Molecular Pathogenesis, Jena, Germany
- Chair for Microbial Ecology, Institute for Food and Health (ZIEL), TUM School of Life Sciences, Technische Universität München, Freising, Germany
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Loulou A, Mastore M, Caramella S, Bhat AH, Brivio MF, Machado RAR, Kallel S. Entomopathogenic potential of bacteria associated with soil-borne nematodes and insect immune responses to their infection. PLoS One 2023; 18:e0280675. [PMID: 36689436 PMCID: PMC10045567 DOI: 10.1371/journal.pone.0280675] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/08/2022] [Accepted: 01/06/2023] [Indexed: 01/24/2023] Open
Abstract
Soil-borne nematodes establish close associations with several bacterial species. Whether they confer benefits to their hosts has been investigated in only a few nematode-bacteria systems. Their ecological function, therefore, remains poorly understood. In this study, we isolated several bacterial species from rhabditid nematodes, molecularly identified them, evaluated their entomopathogenic potential on Galleria mellonella larvae, and measured immune responses of G. mellonella larvae to their infection. Bacteria were isolated from Acrobeloides sp., A. bodenheimeri, Heterorhabditis bacteriophora, Oscheius tipulae, and Pristionchus maupasi nematodes. They were identified as Acinetobacter sp., Alcaligenes sp., Bacillus cereus, Enterobacter sp., Kaistia sp., Lysinibacillus fusiformis, Morganella morganii subsp. morganii, Klebsiella quasipneumoniae subsp. quasipneumoniae, and Pseudomonas aeruginosa. All bacterial strains were found to be highly entomopathogenic as they killed at least 53.33% G. mellonella larvae within 72h post-infection, at a dose of 106 CFU/larvae. Among them, Lysinibacillus fusiformis, Enterobacter sp., Acinetobacter sp., and K. quasipneumoniae subsp. quasipneumoniae were the most entomopathogenic bacteria. Insects strongly responded to bacterial infection. However, their responses were apparently little effective to counteract bacterial infection. Our study, therefore, shows that bacteria associated with soil-borne nematodes have entomopathogenic capacities. From an applied perspective, our study motivates more research to determine the potential of these bacterial strains as biocontrol agents in environmentally friendly and sustainable agriculture.
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Affiliation(s)
- Ameni Loulou
- Department of Plant Health and Environment, Laboratory of Bio-Aggressor and Integrated Protection in Agriculture, National Agronomic Institute of Tunisia, University of Carthage, Tunis, Tunisia
| | - Maristella Mastore
- Department of Theoretical and Applied Sciences, Laboratory of Comparative Immunology and Parasitology, University of Insubria, Varese, Italy
| | - Sara Caramella
- Department of Theoretical and Applied Sciences, Laboratory of Comparative Immunology and Parasitology, University of Insubria, Varese, Italy
| | - Aashaq Hussain Bhat
- Faculty of Sciences, Experimental Biology Research Group, Institute of Biology, University of Neuchâtel, Neuchâtel, Switzerland
| | - Maurizio Francesco Brivio
- Department of Theoretical and Applied Sciences, Laboratory of Comparative Immunology and Parasitology, University of Insubria, Varese, Italy
| | - Ricardo A. R. Machado
- Faculty of Sciences, Experimental Biology Research Group, Institute of Biology, University of Neuchâtel, Neuchâtel, Switzerland
| | - Sadreddine Kallel
- Department of Plant Health and Environment, Laboratory of Bio-Aggressor and Integrated Protection in Agriculture, National Agronomic Institute of Tunisia, University of Carthage, Tunis, Tunisia
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Liu J, Bai H, Song P, Nangong Z, Dong Z, Li Z, Wang Q. Insecticidal Activity of Chitinases from Xenorhabdus nematophila HB310 and Its Relationship with the Toxin Complex. Toxins (Basel) 2022; 14:toxins14090646. [PMID: 36136584 PMCID: PMC9505380 DOI: 10.3390/toxins14090646] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/08/2022] [Revised: 09/07/2022] [Accepted: 09/15/2022] [Indexed: 11/18/2022] Open
Abstract
Xenorhabdus nematophila HB310 secreted the insecticidal protein toxin complex (Tc). The chi60 and chi70 chitinase genes are located on the gene cluster encoding Tc toxins. To clarify the insecticidal activity of chitinases and their relationship with Tc toxins, the insecticidal activity of the chitinases was assessed on Helicoverpa armigera. Then, the chi60 and chi70 genes of X. nematophila HB310 were knocked out by the pJQ200SK suicide plasmid knockout system. The insecticidal activity of Tc toxin from the wild-type strain (WT) and mutant strains was carried out. The results demonstrate that Chi60 and Chi70 had an obvious growth inhibition effect against the second instar larvae of H. armigera with growth-inhibiting rates of 81.99% and 90.51%, respectively. Chi70 had a synergistic effect with the insecticidal toxicity of Tc toxins, but Chi60 had no synergistic effect with Tc toxins. After feeding Chi60 and Chi70, the peritrophic membrane of H. armigera became inelastic, was easily broken and leaked blue dextran. The Δchi60, Δchi70 and Δchi60-chi70 mutant strains were successfully screened. The toxicity of Tc toxins from the WT, Δchi60, Δchi70 and Δchi60-chi70 was 196.11 μg/mL, 757.25 μg/mL, 885.74 μg/mL and 20,049.83 μg/mL, respectively. The insecticidal activity of Tc toxins from Δchi60 and Δchi70 was 3.861 and 4.517 times lower than that of Tc toxins from the WT, respectively, while the insecticidal activity of Tc toxins from the Δchi60-chi70 mutant strain almost disappeared. These results indicate that the presence of chi60 and chi70 is indispensable for the toxicity of Tc toxins.
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Affiliation(s)
- Jia Liu
- Institute of Millet Crops, Hebei Academy of Agriculture and Forestry Sciences, National Foxtail Millet Improvement Center, Minor Cereal Crops Laboratory of Hebei Province, Shijiazhuang 050035, China
| | - Hui Bai
- Institute of Millet Crops, Hebei Academy of Agriculture and Forestry Sciences, National Foxtail Millet Improvement Center, Minor Cereal Crops Laboratory of Hebei Province, Shijiazhuang 050035, China
| | - Ping Song
- College of Plant Protection, Hebei Agricultural University, Baoding 071000, China
| | - Ziyan Nangong
- College of Plant Protection, Hebei Agricultural University, Baoding 071000, China
| | - Zhiping Dong
- Institute of Millet Crops, Hebei Academy of Agriculture and Forestry Sciences, National Foxtail Millet Improvement Center, Minor Cereal Crops Laboratory of Hebei Province, Shijiazhuang 050035, China
| | - Zhiyong Li
- Institute of Millet Crops, Hebei Academy of Agriculture and Forestry Sciences, National Foxtail Millet Improvement Center, Minor Cereal Crops Laboratory of Hebei Province, Shijiazhuang 050035, China
- Correspondence: (Z.L.); (Q.W.)
| | - Qinying Wang
- College of Plant Protection, Hebei Agricultural University, Baoding 071000, China
- Correspondence: (Z.L.); (Q.W.)
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9
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The Insect Pathogen Photorhabdus luminescens Protects Plants from Phytopathogenic Fusarium graminearum via Chitin Degradation. Appl Environ Microbiol 2022; 88:e0064522. [PMID: 35604230 DOI: 10.1128/aem.00645-22] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Phytopathogens represent a large agricultural challenge. The use of chemical pesticides is harmful to the environment, animals, and humans. Therefore, new sustainable and biological alternatives are urgently needed. The insect-pathogenic bacterium Photorhabdus luminescens, already used in combination with entomopathogenic nematodes (EPNs) as a biocontrol agent, is characterized by two different phenotypic cell forms, called primary (1°) and secondary (2°). The 1° cells are symbiotic with EPNs and are used for biocontrol, and the 2° cells are unable to undergo symbiosis with EPNs, remain in the soil after insect infection, and specifically interact with plant roots. A previous RNA sequencing (RNAseq) analysis showed that genes encoding the exochitinase Chi2A and chitin binding protein (CBP) are highly upregulated in 2° cells exposed to plant root exudates. Here, we investigate Chi2A and CBP functions and demonstrate that both are necessary for P. luminescens 2° cells to inhibit the growth of the phytopathogenic fungus Fusarium graminearum. We provide evidence that Chi2A digests chitin and thereby inhibits fungal growth. Furthermore, we show that 2° cells specifically colonize fungal hyphae as one of the first mechanisms to protect plants from fungal phytopathogens. Finally, soil pot bioassays proved plant protection from F. graminearum by 2° cells, where Chi2A and CPB were essential for this process. This work gives molecular insights into the new applicability of P. luminescens as a plant-growth-promoting and plant-protecting organism in agriculture. IMPORTANCE The enteric enterobacterium Photorhabdus luminescens is already being used as a bioinsecticide since it is highly pathogenic toward a broad range of insects. However, the bacteria exist in two phenotypically different cell types, called 1° and 2° cells. Whereas only 1° cells are symbiotic with their nematode partner to infect insects, 2° cells were shown to remain in the soil after an insect infection cycle. It was demonstrated that 2° cells specifically interact with plant roots. Here, we show that the bacteria are beneficial for the plants by protecting them from phytopathogenic fungi. Specific colonization of the fungus mycelium as well as chitin-degrading activity mediated by the chitin binding protein (CBP) and the chitinase Chi2A are essential for this process. Our data give evidence for the novel future applicability of P. luminescens as a plant-growth-promoting organism and biopesticide.
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10
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Schoof M, O’Callaghan M, Sheen CR, Glare TR, Hurst MRH. Identification of genes involved in exoprotein release using a high-throughput exoproteome screening assay in Yersinia entomophaga. PLoS One 2022; 17:e0263019. [PMID: 35077520 PMCID: PMC8789137 DOI: 10.1371/journal.pone.0263019] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/10/2021] [Accepted: 01/10/2022] [Indexed: 11/19/2022] Open
Abstract
Bacterial protein secretion is crucial to the maintenance of viability and pathogenicity. Although many bacterial secretion systems have been identified, the underlying mechanisms regulating their expression are less well explored. Yersinia entomophaga MH96, an entomopathogenic bacterium, releases an abundance of proteins including the Yen-Tc into the growth medium when cultured in Luria Bertani broth at ≤ 25°C. Through the development of a high-throughput exoproteome screening assay (HESA), genes involved in MH96 exoprotein production were identified. Of 4,080 screened transposon mutants, 34 mutants exhibited a decreased exoprotein release, and one mutation located in the intergenic region of the Yen-Tc operon displayed an elevated exoprotein release relative to the wild-type strain MH96. DNA sequencing revealed several transposon insertions clustered in gene regions associated with lipopolysaccharide (LPSI and LPSII), and N-acyl-homoserine lactone synthesis (quorum sensing). Twelve transposon insertions were located within transcriptional regulators or intergenic regions. The HESA will have broad applicability for identifying genes associated with exoproteome production in a range of microorganisms.
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Affiliation(s)
- Marion Schoof
- Bio-Protection Research Centre, Lincoln University, Lincoln, Christchurch, New Zealand
- AgResearch, Forage Science, Lincoln Research Centre, Christchurch, New Zealand
- * E-mail: (MS); (MRHH)
| | - Maureen O’Callaghan
- Bio-Protection Research Centre, Lincoln University, Lincoln, Christchurch, New Zealand
- AgResearch, Forage Science, Lincoln Research Centre, Christchurch, New Zealand
| | - Campbell R. Sheen
- Protein Science and Engineering, Callaghan Innovation, Christchurch, New Zealand
| | - Travis R. Glare
- Bio-Protection Research Centre, Lincoln University, Lincoln, Christchurch, New Zealand
| | - Mark R. H. Hurst
- Bio-Protection Research Centre, Lincoln University, Lincoln, Christchurch, New Zealand
- AgResearch, Forage Science, Lincoln Research Centre, Christchurch, New Zealand
- * E-mail: (MS); (MRHH)
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11
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Identification of Diverse Toxin Complex Clusters and an eCIS Variant in Serratia proteamaculans Pathovars of the New Zealand Grass Grub ( Costelytra Giveni) and Manuka Beetle ( Pyronota Spp.) Larvae. Microbiol Spectr 2021; 9:e0112321. [PMID: 34668742 PMCID: PMC8528098 DOI: 10.1128/spectrum.01123-21] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/01/2022] Open
Abstract
The grass grub endemic to New Zealand, Costelytra giveni (Coleoptera: Scarabaeidae), and the manuka beetle, Pyronota festiva and P. setosa (Coleoptera: Scarabaeidae), are prevalent pest species. Through assessment of bacterial strains isolated from diseased cadavers of these insect species, 19 insect-active Serratia proteamaculans variants and a single Serratia entomophila strain were isolated. When independently bioassayed, these isolates differed in host range, the rate of disease progression, and 12-day mortality rates, which ranged from 60 to 100% of the challenged larvae. A Pyronota spp.-derived S. proteamaculans isolate caused a transient disease phenotype in challenged C. giveni larvae, whereby larvae appeared diseased before recovering to a healthy state. Genome sequence analysis revealed that all but two of the sequenced isolates contained a variant of the S. entomophila amber-disease-associated plasmid, pADAP. Each isolate also encoded one of seven distinct members of the toxin complex (Tc) family of insect-active toxins, five of which are newly described, or a member of the extracellular contractile injection (eCIS) machine family, with a new AfpX variant designated SpF. Targeted mutagenesis of each of the predicted Tc- or eCIS-encoding regions abolished or attenuated pathogenicity. Host-range testing showed that several of the S. proteamaculans Tc-encoding isolates affected both Pyronota and C. giveni species, with other isolates specific for either Pyronota spp. or C. giveni. The isolation of several distinct host-specific pathotypes of Serratia spp. may reflect pathogen-host speciation. IMPORTANCE New pathotypes of the insect pathogen Serratia, each with differing virulence attributes and host specificity toward larvae of the New Zealand manuka beetle and grass grub, have been identified. All of the Serratia proteamaculans isolates contained one of seven different insect-active toxin clusters or one of three eCIS variants. The diversity of these Serratia-encoded virulence clusters, resulting in differences in larval disease progression and host specificity in endemic scarab larvae, suggests speciation of these pathogens with their insect hosts. The differing virulence properties of these Serratia species may affect their potential infectivity and distribution among the insect populations. Based on their differing geographic isolation and pathotypes, several of these Serratia isolates, including the manuka beetle-active isolates, are likely to be more effective biopesticides in specific environments or could be used in combination for greater effect.
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12
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Song N, Chen L, Zhou Z, Ren X, Liu B, Zhou S, Wang C, Wu Y, Waterfield NR, Yang J, Yang G. Genome-wide dissection reveals diverse pathogenic roles of bacterial Tc toxins. PLoS Pathog 2021; 17:e1009102. [PMID: 33540421 PMCID: PMC7861908 DOI: 10.1371/journal.ppat.1009102] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/06/2020] [Accepted: 10/26/2020] [Indexed: 12/21/2022] Open
Abstract
Tc toxins were originally identified in entomopathogenic bacteria, which are important as biological pest control agents. Tc toxins are heteromeric exotoxins composed of three subunit types, TcA, TcB, and TcC. The C-terminal portion of the TcC protein encodes the actual toxic domain, which is translocated into host cells by an injectosome nanomachine comprising the other subunits. Currently the pathogenic roles and distribution of Tc toxins among different bacterial genera remain unclear. Here we have performed a comprehensive genome-wide analysis, and established a database that includes 1,608 identified Tc loci containing 2,528 TcC proteins in 1,421 Gram-negative and positive bacterial genomes. Our findings indicate that TcCs conform to the architecture of typical polymorphic toxins, with C-terminal hypervariable regions (HVR) encoding more than 100 different classes of putative toxic domains, most of which have not been previously recognized. Based on further analysis of Tc loci in the genomes of all Salmonella and Yersinia strains in EnteroBase, a “two-level” evolutionary dynamics scenario is proposed for TcC homologues. This scenario implies that the conserved TcC RHS core domain plays a critical role in the taxonomical specific distribution of TcC HVRs. This study provides an extensive resource for the future development of Tc toxins as valuable agrochemical tools. It furthermore implies that Tc proteins, which are encoded by a wide range of pathogens, represent an important versatile toxin superfamily with diverse pathogenic mechanisms. Entomopathogenic bacteria deploy a range of toxins to combat their insect hosts. The Tc toxins were first identified in Photorhabdus as having potent oral toxicity to insects, with a mode of action distinct from the well-studied Bacillus thuringiensis Cry toxins. As such the Tc toxins have been considered as potential candidates for novel crop protection strategies. This could mitigate against the potential risks of pest insects developing resistance to the traditionally used Cry toxin-based systems. To date, the generality of diverse Tc toxins and their related pathogenic roles has remained mainly obscure. Our analysis has showed Tc toxins are widely distributed among Gram-negative and positive bacterial genomes. A database was constructed including thousands of Tc loci with hundreds of different putative TcC toxic domains, any one of which might represent candidates for the development of future pest control systems. Moreover, the findings of this study are of wider significance because Tc toxin homologues have been shown to be encoded by a range of human pathogens. These include Salmonella and Yersinia, suggesting their potential roles in human infectious diseases. Together, this study describes the characteristics and distribution of Tc toxins among diverse bacterial genera, and provides a new insight into their roles in different pathogenesis mechanisms. This study also describes findings of potential importance to their development as tools for biotechnological applications.
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Affiliation(s)
- Nan Song
- Beijing Institute of Tropical Medicine, Beijing, China
- Emergency and Critical Care Center, Beijing Friendship Hospital, Capital Medical University, Beijing, China
| | - Lihong Chen
- NHC Key Laboratory of Systems Biology of Pathogens, Institute of Pathogen Biology, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing, China
| | - Zhemin Zhou
- Warwick Medical School, Warwick University, Coventry, United Kingdom
| | - Xingmei Ren
- Beijing Institute of Tropical Medicine, Beijing, China
- Emergency and Critical Care Center, Beijing Friendship Hospital, Capital Medical University, Beijing, China
| | - Bo Liu
- NHC Key Laboratory of Systems Biology of Pathogens, Institute of Pathogen Biology, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing, China
| | - Siyu Zhou
- NHC Key Laboratory of Systems Biology of Pathogens, Institute of Pathogen Biology, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing, China
| | - Caihong Wang
- Beijing Institute of Tropical Medicine, Beijing, China
- Emergency and Critical Care Center, Beijing Friendship Hospital, Capital Medical University, Beijing, China
| | - Yun Wu
- Beijing Institute of Tropical Medicine, Beijing, China
- Emergency and Critical Care Center, Beijing Friendship Hospital, Capital Medical University, Beijing, China
| | | | - Jian Yang
- NHC Key Laboratory of Systems Biology of Pathogens, Institute of Pathogen Biology, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing, China
- * E-mail: (JY); (GY)
| | - Guowei Yang
- Beijing Institute of Tropical Medicine, Beijing, China
- Emergency and Critical Care Center, Beijing Friendship Hospital, Capital Medical University, Beijing, China
- * E-mail: (JY); (GY)
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13
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Paulson AR, O’Callaghan M, Zhang XX, Rainey PB, Hurst MRH. In vivo transcriptome analysis provides insights into host-dependent expression of virulence factors by Yersinia entomophaga MH96, during infection of Galleria mellonella. G3 (BETHESDA, MD.) 2021; 11:jkaa024. [PMID: 33561230 PMCID: PMC7849909 DOI: 10.1093/g3journal/jkaa024] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 09/01/2020] [Accepted: 11/19/2020] [Indexed: 12/31/2022]
Abstract
The function of microbes can be inferred from knowledge of genes specifically expressed in natural environments. Here, we report the in vivo transcriptome of the entomopathogenic bacterium Yersinia entomophaga MH96, captured during initial, septicemic, and pre-cadaveric stages of intrahemocoelic infection in Galleria mellonella. A total of 1285 genes were significantly upregulated by MH96 during infection; 829 genes responded to in vivo conditions during at least one stage of infection, 289 responded during two stages of infection, and 167 transcripts responded throughout all three stages of infection compared to in vitro conditions at equivalent cell densities. Genes upregulated during the earliest infection stage included components of the insecticidal toxin complex Yen-TC (chi1, chi2, and yenC1), genes for rearrangement hotspot element containing protein yenC3, cytolethal distending toxin cdtAB, and vegetative insecticidal toxin vip2. Genes more highly expressed throughout the infection cycle included the putative heat-stable enterotoxin yenT and three adhesins (usher-chaperone fimbria, filamentous hemagglutinin, and an AidA-like secreted adhesin). Clustering and functional enrichment of gene expression data also revealed expression of genes encoding type III and VI secretion system-associated effectors. Together these data provide insight into the pathobiology of MH96 and serve as an important resource supporting efforts to identify novel insecticidal agents.
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Affiliation(s)
- Amber R Paulson
- Forage Science, AgResearch Ltd., Lincoln 8140, New Zealand
- New Zealand Institute for Advanced Study, Massey University, Auckland 0745, New Zealand
- Department of Biology, Queen’s University, Kingston, ON K7L 3N6, Canada
| | | | - Xue-Xian Zhang
- School of Natural and Computational Sciences, Massey University, Auckland 0745, New Zealand
| | - Paul B Rainey
- New Zealand Institute for Advanced Study, Massey University, Auckland 0745, New Zealand
- Laboratoire de Génétique de l’Evolution CBI, ESPCI Paris, Université PSL, CNRS, Paris 75005, France
- Department of Microbial Population Biology, Max Planck Institute for Evolutionary Biology, Plön 24306, Germany
| | - Mark R H Hurst
- Forage Science, AgResearch Ltd., Lincoln 8140, New Zealand
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14
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Hurst MRH, Jones S, Young S, Muetzel S, Calder J, van Koten C. Assessment of toxicity and persistence of Yersinia entomophaga and its Yen-Tc associated toxin. PEST MANAGEMENT SCIENCE 2020; 76:4301-4310. [PMID: 32648630 DOI: 10.1002/ps.5997] [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: 02/03/2020] [Revised: 06/06/2020] [Accepted: 07/10/2020] [Indexed: 06/11/2023]
Abstract
BACKGROUND The insect-pathogenic bacterium Yersinia entomophaga MH96 is currently under development as a microbial pesticide active against various pasture and crop pests such as the diamondback moth Plutella xylostella and the cotton bollworm Helicoverpa armigeria. To enable nonrestricted field trials of Y. entomophaga MH96, information on the persistence and nontarget effects of the bacterium and its Yen-Tc proteinaceous toxin are required. RESULTS The Y. entomophaga Yen-Tc associated toxin was found to have limited persistence on foliage and is inactivated by UV light. The Yen-Tc was rapidly degraded in ovine or bovine rumen fluid or the intestinal fluid of H. armigera. In H. armigera an intestinal protein of >50 kDa was found to cleave the Yen-Tc bond. Assessment of Y. entomophaga persistence on foliage and in soil found that after 42 days the bacterium could not be detected in soil at 20% soil moisture content but persisted for 72 days at 30-40% soil moisture. Nontarget effects of Y. entomophaga towards earthworms found that the bacterium afforded no adverse effects on worm growth or behavior. A summary of historic Yen-Tc and Y. entomophaga persistence and toxicity data is presented. CONCLUSION The bacterium Y. entomophaga and its Yen-Tc associated toxin have limited persistence in the environment, with the Yen-Tc being susceptible to UV inactivation and proteolytic degradation, and the bacterium persisting longer in soil of a high moisture content. © 2020 Society of Chemical Industry.
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Affiliation(s)
| | - Sandra Jones
- Forage Science, AgResearch, Lincoln Research Centre, Christchurch, New Zealand
| | - Sandra Young
- Forage Science, AgResearch, Lincoln Research Centre, Christchurch, New Zealand
| | - Stefan Muetzel
- Animal Science, AgResearch, Grasslands Research Centre, Palmerston North, New Zealand
| | - Joanne Calder
- Forage Science, AgResearch, Lincoln Research Centre, Christchurch, New Zealand
| | - Chikako van Koten
- Knowledge & Analytics, AgResearch, Lincoln Research Centre, Christchurch, New Zealand
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15
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Mansfield S, Wilson MJ, Gerard PJ, Wilson DJ, Swaminathan J, Wright DA, van Koten C, Hurst MR. Potential for a biopesticide bait to control black beetle, Heteronychus arator (Coleoptera: Scarabaeidae). PEST MANAGEMENT SCIENCE 2020; 76:4150-4158. [PMID: 32592433 DOI: 10.1002/ps.5973] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/28/2019] [Revised: 06/03/2020] [Accepted: 06/27/2020] [Indexed: 06/11/2023]
Abstract
BACKGROUND Yersinia entomophaga is an entomopathogenic bacterium that is active against scarab beetles, among other insects. In New Zealand, the African black beetle, Heteronychus arator (Coleoptera: Scarabaeidae), is a major pest of pastures and arable crops but very few control options exist and no insecticides are registered for use in established pastures. RESULTS In laboratory bioassays, H. arator adults were susceptible to a bait containing Y. entomophaga at low doses. This bait was more effective against H. arator adults during spring than autumn in small-scale field plots (320 mm diameter). A large-scale field trial (40 × 40 m plots) reduced adult numbers substantially: approximately twice as many beetles were captured in pitfall traps from untreated plots compared with plots treated with the Y. entomophaga bait at 70 kg ha-1 . This single bait application in spring also reduced subsequent larval populations in summer. CONCLUSIONS Heteronychus arator is a difficult pest to manage using chemical insecticides. This biopesticide with Y. entomophaga as the active ingredient offers a new solution for New Zealand pastures, with potential for application to other crops affected by H. arator and for control of other pests. © 2020 Society of Chemical Industry.
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Affiliation(s)
| | | | | | | | - Jayanthi Swaminathan
- AgResearch, Lincoln Science Centre, Lincoln, New Zealand
- Faculty of Agriculture and Life Sciences, Lincoln University, Lincoln, New Zealand
| | - David A Wright
- AgResearch, Lincoln Science Centre, Lincoln, New Zealand
| | | | - Mark Rh Hurst
- AgResearch, Lincoln Science Centre, Lincoln, New Zealand
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16
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Ost GS, Wirth C, Bogdanović X, Kao WC, Schorch B, Aktories PJK, Papatheodorou P, Schwan C, Schlosser A, Jank T, Hunte C, Aktories K. Inverse control of Rab proteins by Yersinia ADP-ribosyltransferase and glycosyltransferase related to clostridial glucosylating toxins. SCIENCE ADVANCES 2020; 6:eaaz2094. [PMID: 32195351 PMCID: PMC7065874 DOI: 10.1126/sciadv.aaz2094] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/21/2019] [Accepted: 12/17/2019] [Indexed: 05/20/2023]
Abstract
We identified a glucosyltransferase (YGT) and an ADP-ribosyltransferase (YART) in Yersinia mollaretii, highly related to glucosylating toxins from Clostridium difficile, the cause of antibiotics-associated enterocolitis. Both Yersinia toxins consist of an amino-terminal enzyme domain, an autoprotease domain activated by inositol hexakisphosphate, and a carboxyl-terminal translocation domain. YGT N-acetylglucosaminylates Rab5 and Rab31 at Thr52 and Thr36, respectively, thereby inactivating the Rab proteins. YART ADP-ribosylates Rab5 and Rab31 at Gln79 and Gln64, respectively. This activates Rab proteins by inhibiting GTP hydrolysis. We determined the crystal structure of the glycosyltransferase domain of YGT (YGTG) in the presence and absence of UDP at 1.9- and 3.4-Å resolution, respectively. Thereby, we identified a previously unknown potassium ion-binding site, which explains potassium ion-dependent enhanced glycosyltransferase activity in clostridial and related toxins. Our findings exhibit a novel type of inverse regulation of Rab proteins by toxins and provide new insights into the structure-function relationship of glycosyltransferase toxins.
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Affiliation(s)
- G. Stefan Ost
- Institut für Experimentelle und Klinische Pharmakologie und Toxikologie, Medizinische Fakultät, Albert-Ludwigs-Universität Freiburg, 79104 Freiburg, Germany
- Institut für Biologie, Fakultät für Biologie, Albert-Ludwigs-Universität Freiburg, 79104 Freiburg, Germany
| | - Christophe Wirth
- Institut für Biochemie und Molekularbiologie, ZBMZ, Medizinische Fakultät, Albert-Ludwigs-Universität Freiburg, 79104 Freiburg, Germany
| | - Xenia Bogdanović
- Institut für Biochemie und Molekularbiologie, ZBMZ, Medizinische Fakultät, Albert-Ludwigs-Universität Freiburg, 79104 Freiburg, Germany
| | - Wei-Chun Kao
- Institut für Biochemie und Molekularbiologie, ZBMZ, Medizinische Fakultät, Albert-Ludwigs-Universität Freiburg, 79104 Freiburg, Germany
| | - Björn Schorch
- Institut für Experimentelle und Klinische Pharmakologie und Toxikologie, Medizinische Fakultät, Albert-Ludwigs-Universität Freiburg, 79104 Freiburg, Germany
| | - Philipp J. K. Aktories
- Institut für Experimentelle und Klinische Pharmakologie und Toxikologie, Medizinische Fakultät, Albert-Ludwigs-Universität Freiburg, 79104 Freiburg, Germany
| | - Panagiotis Papatheodorou
- Institut für Experimentelle und Klinische Pharmakologie und Toxikologie, Medizinische Fakultät, Albert-Ludwigs-Universität Freiburg, 79104 Freiburg, Germany
| | - Carsten Schwan
- Institut für Experimentelle und Klinische Pharmakologie und Toxikologie, Medizinische Fakultät, Albert-Ludwigs-Universität Freiburg, 79104 Freiburg, Germany
| | - Andreas Schlosser
- Rudolf-Virchow-Zentrum für Experimentelle Biomedizin, Universität Würzburg, 97080 Würzburg, Germany
| | - Thomas Jank
- Institut für Experimentelle und Klinische Pharmakologie und Toxikologie, Medizinische Fakultät, Albert-Ludwigs-Universität Freiburg, 79104 Freiburg, Germany
| | - Carola Hunte
- Institut für Biochemie und Molekularbiologie, ZBMZ, Medizinische Fakultät, Albert-Ludwigs-Universität Freiburg, 79104 Freiburg, Germany
- Centre for Biological Signalling Studies (BIOSS), Albert-Ludwigs-Universität Freiburg, 79104 Freiburg, Germany
- CIBSS–Centre for Integrative Biological Signalling Studies, University of Freiburg, 79104 Freiburg, Germany
| | - Klaus Aktories
- Institut für Experimentelle und Klinische Pharmakologie und Toxikologie, Medizinische Fakultät, Albert-Ludwigs-Universität Freiburg, 79104 Freiburg, Germany
- Centre for Biological Signalling Studies (BIOSS), Albert-Ludwigs-Universität Freiburg, 79104 Freiburg, Germany
- Corresponding author.
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17
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Perspectives of Microbial Metabolites as Pesticides in Agricultural Pest Management. REFERENCE SERIES IN PHYTOCHEMISTRY 2020. [DOI: 10.1007/978-3-319-96397-6_44] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/11/2023]
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18
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Roderer D, Raunser S. Tc Toxin Complexes: Assembly, Membrane Permeation, and Protein Translocation. Annu Rev Microbiol 2019; 73:247-265. [DOI: 10.1146/annurev-micro-102215-095531] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
Tc toxin complexes are virulence factors of many bacteria, including insect and human pathogens. Tc toxins are composed of three subunits that act together to perforate the host membrane, similar to a syringe, and translocate toxic enzymes into the host cell. The reactions of the toxic enzymes lead to deterioration and ultimately death of the cell. We review recent high-resolution structural and functional data that explain the mechanism of action of this type of bacterial toxin at an unprecedented level of molecular detail. We focus on the steps that are necessary for toxin activation and membrane permeation. This is where the largest conformational transitions appear. Furthermore, we compare the architecture and function of Tc toxins with those of anthrax toxin and vertebrate teneurin.
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Affiliation(s)
- Daniel Roderer
- Department of Structural Biochemistry, Max Planck Institute of Molecular Physiology, 44227 Dortmund, Germany;,
| | - Stefan Raunser
- Department of Structural Biochemistry, Max Planck Institute of Molecular Physiology, 44227 Dortmund, Germany;,
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19
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Microbial biopesticides for control of invertebrates: Progress from New Zealand. J Invertebr Pathol 2019; 165:82-88. [DOI: 10.1016/j.jip.2017.11.014] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/20/2017] [Revised: 11/26/2017] [Accepted: 11/27/2017] [Indexed: 11/19/2022]
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20
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Piper SJ, Brillault L, Rothnagel R, Croll TI, Box JK, Chassagnon I, Scherer S, Goldie KN, Jones SA, Schepers F, Hartley-Tassell L, Ve T, Busby JN, Dalziel JE, Lott JS, Hankamer B, Stahlberg H, Hurst MRH, Landsberg MJ. Cryo-EM structures of the pore-forming A subunit from the Yersinia entomophaga ABC toxin. Nat Commun 2019; 10:1952. [PMID: 31028251 PMCID: PMC6486591 DOI: 10.1038/s41467-019-09890-8] [Citation(s) in RCA: 23] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/17/2018] [Accepted: 04/05/2019] [Indexed: 11/15/2022] Open
Abstract
ABC toxins are pore-forming virulence factors produced by pathogenic bacteria. YenTcA is the pore-forming and membrane binding A subunit of the ABC toxin YenTc, produced by the insect pathogen Yersinia entomophaga. Here we present cryo-EM structures of YenTcA, purified from the native source. The soluble pre-pore structure, determined at an average resolution of 4.4 Å, reveals a pentameric assembly that in contrast to other characterised ABC toxins is formed by two TcA-like proteins (YenA1 and YenA2) and decorated by two endochitinases (Chi1 and Chi2). We also identify conformational changes that accompany membrane pore formation by visualising YenTcA inserted into liposomes. A clear outward rotation of the Chi1 subunits allows for access of the protruding translocation pore to the membrane. Our results highlight structural and functional diversity within the ABC toxin subfamily, explaining how different ABC toxins are capable of recognising diverse hosts. YenTcA is the pore-forming and membrane binding subunit of the ABC toxin YenTc, which is produced by the insect pathogen Yersinia entomophaga. Here authors present cryo-EM structures of YenTcA purified from the native source which implicate associated endochitinases in host cell recognition.
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Affiliation(s)
- Sarah J Piper
- School of Chemistry and Molecular Biosciences, The University of Queensland, St Lucia Queensland, 4072, Australia.,Institute for Molecular Bioscience, The University of Queensland, St Lucia Queensland, 4072, Australia
| | - Lou Brillault
- School of Chemistry and Molecular Biosciences, The University of Queensland, St Lucia Queensland, 4072, Australia.,Institute for Molecular Bioscience, The University of Queensland, St Lucia Queensland, 4072, Australia
| | - Rosalba Rothnagel
- Institute for Molecular Bioscience, The University of Queensland, St Lucia Queensland, 4072, Australia
| | - Tristan I Croll
- Cambridge Institute of Medical Research, University of Cambridge, Cambridge Cambridgeshire, CB2 0XY, United Kingdom
| | - Joseph K Box
- School of Chemistry and Molecular Biosciences, The University of Queensland, St Lucia Queensland, 4072, Australia
| | - Irene Chassagnon
- School of Chemistry and Molecular Biosciences, The University of Queensland, St Lucia Queensland, 4072, Australia
| | - Sebastian Scherer
- Centre for Cellular Imaging and NanoAnalytics, Biozentrum, University of Basel, 4058, Basel, Switzerland
| | - Kenneth N Goldie
- Centre for Cellular Imaging and NanoAnalytics, Biozentrum, University of Basel, 4058, Basel, Switzerland
| | - Sandra A Jones
- Forage Science Group, AgResearch, Christchurch, 8140, New Zealand
| | - Femke Schepers
- Faculty of Science, Leiden University, 2300 RA, Leiden, The Netherlands.,Food & Bio-based Products Group, AgResearch, Palmerston North, 4442, New Zealand
| | | | - Thomas Ve
- Institute for Glycomics, Griffith University, Gold Coast Queensland, 4222, Australia
| | - Jason N Busby
- School of Biological Sciences, University of Auckland, Auckland, 1142, New Zealand
| | - Julie E Dalziel
- Food & Bio-based Products Group, AgResearch, Palmerston North, 4442, New Zealand
| | - J Shaun Lott
- School of Biological Sciences, University of Auckland, Auckland, 1142, New Zealand
| | - Ben Hankamer
- Institute for Molecular Bioscience, The University of Queensland, St Lucia Queensland, 4072, Australia
| | - Henning Stahlberg
- Centre for Cellular Imaging and NanoAnalytics, Biozentrum, University of Basel, 4058, Basel, Switzerland
| | - Mark R H Hurst
- Forage Science Group, AgResearch, Christchurch, 8140, New Zealand
| | - Michael J Landsberg
- School of Chemistry and Molecular Biosciences, The University of Queensland, St Lucia Queensland, 4072, Australia. .,Institute for Molecular Bioscience, The University of Queensland, St Lucia Queensland, 4072, Australia.
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21
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Jackson VA, Busby JN, Janssen BJC, Lott JS, Seiradake E. Teneurin Structures Are Composed of Ancient Bacterial Protein Domains. Front Neurosci 2019; 13:183. [PMID: 30930731 PMCID: PMC6425310 DOI: 10.3389/fnins.2019.00183] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/16/2018] [Accepted: 02/15/2019] [Indexed: 11/16/2022] Open
Abstract
Pioneering bioinformatic analysis using sequence data revealed that teneurins evolved from bacterial tyrosine-aspartate (YD)-repeat protein precursors. Here, we discuss how structures of the C-terminal domain of teneurins, determined using X-ray crystallography and electron microscopy, support the earlier findings on the proteins’ ancestry. This chapter describes the structure of the teneurin scaffold with reference to a large family of teneurin-like proteins that are widespread in modern prokaryotes. The central scaffold of modern eukaryotic teneurins is decorated by additional domains typically found in bacteria, which are re-purposed in eukaryotes to generate highly multifunctional receptors. We discuss how alternative splicing contributed to further diversifying teneurin structure and thereby function. This chapter traces the evolution of teneurins from a structural point of view and presents the state-of-the-art of how teneurin function is encoded by its specific structural features.
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Affiliation(s)
| | - Jason N Busby
- School of Biological Sciences, The University of Auckland, Auckland, New Zealand
| | - Bert J C Janssen
- Crystal and Structural Chemistry, Bijvoet Center for Biomolecular Research, Faculty of Science, Utrecht University, Utrecht, Netherlands
| | - J Shaun Lott
- School of Biological Sciences, The University of Auckland, Auckland, New Zealand
| | - Elena Seiradake
- Department of Biochemistry, University of Oxford, Oxford, United Kingdom
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Hurst MRH, Jones SA, Beattie A, van Koten C, Shelton AM, Collins HL, Brownbridge M. Assessment of Yersinia entomophaga as a control agent of the diamondback moth Plutella xylostella. J Invertebr Pathol 2019; 162:19-25. [PMID: 30735764 DOI: 10.1016/j.jip.2019.02.002] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/03/2018] [Revised: 12/11/2018] [Accepted: 02/04/2019] [Indexed: 11/25/2022]
Abstract
The application of the biocontrol bacterium Yersinia entomophaga as a foliar spray was assessed for its efficacy against larvae of the diamondback moth, Plutella xylostella. The bacterium was applied as either a broth suspension, or as a biopolymer-based gel foliar spray and compared with commercial insecticides Dipel (Bacillus thuringiensis) and Spinosad. The performance of Y. entomophaga was comparable with that of Dipel. The gel-based formulation extended leaf persistence over that of the basic broth culture spray, while also providing higher initial foliar deposition rates. The bacterium was found to multiply within the P. xylostella larvae to 5.8 × 105 cells per larva, while the median lethal dose (LD50) was determined to be 2.69 × 103 cells per larva. Importantly, B. thuringiensis Cry1A-resistant, Cry1C-resistant, indoxacarb/pyrethroid-resistant, and Spinosad-resistant P. xylostella larvae were susceptible to Y. entomophaga.
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Affiliation(s)
- Mark Robin Holmes Hurst
- Forage Science, AgResearch, Lincoln Research Centre, Private Bag 4749, Christchurch 8140, New Zealand; Bio-Protection Research Centre, Lincoln, Christchurch, New Zealand.
| | - Sandra Andrea Jones
- Forage Science, AgResearch, Lincoln Research Centre, Private Bag 4749, Christchurch 8140, New Zealand
| | - Amy Beattie
- Forage Science, AgResearch, Lincoln Research Centre, Private Bag 4749, Christchurch 8140, New Zealand
| | - Chikako van Koten
- Knowledge & Analytics, AgResearch, Lincoln Research Centre, Private Bag 4749, Christchurch 8140, New Zealand
| | - Anthony Minot Shelton
- New York State Agricultural Experiment Station, Department of Entomology, College of Agriculture and Life Sciences, Cornell University, Geneva, NY, USA
| | - Hilda Lam Collins
- New York State Agricultural Experiment Station, Department of Entomology, College of Agriculture and Life Sciences, Cornell University, Geneva, NY, USA
| | - Michael Brownbridge
- Horticultural Production Systems, Vineland Research and Innovation Centre, Vineland Station, Ontario, Canada
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Perspectives of Microbial Metabolites as Pesticides in Agricultural Pest Management. BIOACTIVE MOLECULES IN FOOD 2019. [DOI: 10.1007/978-3-319-76887-8_44-1] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
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Springer K, Sänger PA, Moritz C, Felsl A, Rattei T, Fuchs TM. Insecticidal Toxicity of Yersinia frederiksenii Involves the Novel Enterotoxin YacT. Front Cell Infect Microbiol 2018; 8:392. [PMID: 30488025 PMCID: PMC6246891 DOI: 10.3389/fcimb.2018.00392] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/20/2018] [Accepted: 10/18/2018] [Indexed: 11/13/2022] Open
Abstract
The genus Yersinia comprises 19 species of which three are known as human and animal pathogens. Some species display toxicity toward invertebrates using the so-called toxin complex (TC) and/or determinants that are not yet known. Recent studies showed a remarkable variability of insecticidal activities when representatives of different Yersinia species (spp.) were subcutaneously injected into the greater wax moth, Galleria mellonella. Here, we demonstrate that Y. intermedia and Y. frederiksenii are highly toxic to this insect. A member of Y. Enterocolitica phylogroup 1B killed G. mellonella larvae with injection doses of approximately 38 cells only, thus resembling the insecticidal activity of Photorhabdus luminescens. The pathogenicity Yersinia spp. displays toward the larvae was higher at 15°C than at 30°C and independent of the TC. However, upon subtraction of all genes of the low-pathogenic Y. enterocolitica strain W22703 from the genomes of Y. intermedia and Y. frederiksenii, we identified a set of genes that may be responsible for the toxicity of these two species. Indeed, a mutant of Y. frederiksenii lacking yacT, a gene that encodes a protein similar to the heat-stable cytotonic enterotoxin (Ast) of Aeromonas hydrophila, exhibited a reduced pathogenicity toward G. mellonella larvae and altered the morphology of hemocytes. The data suggests that the repertoire of virulence determinants present in environmental Yersinia species remains to be elucidated.
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Affiliation(s)
- Katharina Springer
- Lehrstuhl für Mikrobielle Ökologie, Fakultät für Grundlagen der Biowissenschaften, Wissenschaftszentrum Weihenstephan, Technische Universität München, Freising, Germany
| | | | - Christian Moritz
- Lehrstuhl für Mikrobielle Ökologie, Fakultät für Grundlagen der Biowissenschaften, Wissenschaftszentrum Weihenstephan, Technische Universität München, Freising, Germany
| | - Angela Felsl
- Lehrstuhl für Mikrobielle Ökologie, Fakultät für Grundlagen der Biowissenschaften, Wissenschaftszentrum Weihenstephan, Technische Universität München, Freising, Germany
| | - Thomas Rattei
- Department of Computational Systems Biology, University of Vienna, Vienna, Austria
| | - Thilo M Fuchs
- Lehrstuhl für Mikrobielle Ökologie, Fakultät für Grundlagen der Biowissenschaften, Wissenschaftszentrum Weihenstephan, Technische Universität München, Freising, Germany.,Friedrich-Loeffler-Institut, Institut für Molekulare Pathogenese, Jena, Germany
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Vibrio parahaemolyticus RhsP represents a widespread group of pro-effectors for type VI secretion systems. Nat Commun 2018; 9:3899. [PMID: 30254227 PMCID: PMC6156420 DOI: 10.1038/s41467-018-06201-5] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/19/2018] [Accepted: 08/20/2018] [Indexed: 12/31/2022] Open
Abstract
Type VI secretion systems (T6SSs) translocate effector proteins, such as Rhs toxins, to eukaryotic cells or prokaryotic competitors. All T6SS Rhs-type effectors characterized thus far contain a PAAR motif or a similar structure. Here, we describe a T6SS-dependent delivery mechanism for a subset of Rhs proteins that lack a PAAR motif. We show that the N-terminal Rhs domain of protein RhsP (or VP1517) from Vibrio parahaemolyticus inhibits the activity of the C-terminal DNase domain. Upon auto-proteolysis, the Rhs fragment remains inside the cells, and the C-terminal region interacts with PAAR2 and is secreted by T6SS2; therefore, RhsP acts as a pro-effector. Furthermore, we show that RhsP contributes to the control of certain “social cheaters” (opaR mutants). Genes encoding proteins with similar Rhs and PAAR-interacting domains, but diverse C-terminal regions, are widely distributed among Vibrio species. It is unclear how Rhs toxins lacking a PAAR motif are secreted by Type VI secretion systems. Here, the authors show for one of these proteins that the mechanism requires removal of an N-terminal fragment by auto-proteolysis, followed by interaction with a PAAR protein and then secretion.
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Le Guern AS, Savin C, Brémont S, Payro G, Bon D, Carniel E, Pizarro-Cerdá J. First isolation of Yersinia entomophaga in human urinary tract. New Microbes New Infect 2018; 26:3-7. [PMID: 30245826 PMCID: PMC6141728 DOI: 10.1016/j.nmni.2018.08.002] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/29/2018] [Revised: 07/23/2018] [Accepted: 08/03/2018] [Indexed: 01/12/2023] Open
Abstract
Yersinia entomophaga is an insect pathogen first isolated from larvae of Coleoptera in New Zealand in 2011. We report here the first isolation of Y. entomophaga from human urine. Using whole-genome sequencing, we confirmed the presence of specific chromosomal virulence genes and identified a plasmid harbouring a quinolone resistance gene.
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Affiliation(s)
- A-S Le Guern
- Yersinia National Reference Laboratory, Yersinia Research Unit and WHO Collaborating Center for the Yersiniae, Institut Pasteur, Paris, France
| | - C Savin
- Yersinia National Reference Laboratory, Yersinia Research Unit and WHO Collaborating Center for the Yersiniae, Institut Pasteur, Paris, France
| | - S Brémont
- Yersinia National Reference Laboratory, Yersinia Research Unit and WHO Collaborating Center for the Yersiniae, Institut Pasteur, Paris, France
| | - G Payro
- Laboratoire Cerdibio Charentes, Saintes, France
| | - D Bon
- Department of Surgery-Urology, Centre Hospitalier Général, Angoulême, France
| | - E Carniel
- Yersinia National Reference Laboratory, Yersinia Research Unit and WHO Collaborating Center for the Yersiniae, Institut Pasteur, Paris, France
| | - J Pizarro-Cerdá
- Yersinia National Reference Laboratory, Yersinia Research Unit and WHO Collaborating Center for the Yersiniae, Institut Pasteur, Paris, France
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McQuade R, Stock SP. Secretion Systems and Secreted Proteins in Gram-Negative Entomopathogenic Bacteria: Their Roles in Insect Virulence and Beyond. INSECTS 2018; 9:insects9020068. [PMID: 29921761 PMCID: PMC6023292 DOI: 10.3390/insects9020068] [Citation(s) in RCA: 20] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Subscribe] [Scholar Register] [Received: 05/13/2018] [Revised: 06/11/2018] [Accepted: 06/13/2018] [Indexed: 12/12/2022]
Abstract
Many Gram-negative bacteria have evolved insect pathogenic lifestyles. In all cases, the ability to cause disease in insects involves specific bacterial proteins exported either to the surface, the extracellular environment, or the cytoplasm of the host cell. They also have several distinct mechanisms for secreting such proteins. In this review, we summarize the major protein secretion systems and discuss examples of secreted proteins that contribute to the virulence of a variety of Gram-negative entomopathogenic bacteria, including Photorhabdus, Xenorhabdus, Serratia, Yersinia, and Pseudomonas species. We also briefly summarize two classes of exported protein complexes, the PVC-like elements, and the Tc toxin complexes that were first described in entomopathogenic bacteria.
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Affiliation(s)
- Rebecca McQuade
- Center for Insect Science, University of Arizona, 1007 E. Lowell Street, Tucson, AZ 85721, USA.
| | - S Patricia Stock
- Department of Entomology and School of Animal and Comparative Biomedical Sciences, University of Arizona, 1140 E. South Campus Dr., Tucson, AZ 85721, USA.
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28
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Houston S, Lithgow KV, Osbak KK, Kenyon CR, Cameron CE. Functional insights from proteome-wide structural modeling of Treponema pallidum subspecies pallidum, the causative agent of syphilis. BMC STRUCTURAL BIOLOGY 2018; 18:7. [PMID: 29769048 PMCID: PMC5956850 DOI: 10.1186/s12900-018-0086-3] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 12/12/2017] [Accepted: 04/27/2018] [Indexed: 12/21/2022]
Abstract
Background Syphilis continues to be a major global health threat with 11 million new infections each year, and a global burden of 36 million cases. The causative agent of syphilis, Treponema pallidum subspecies pallidum, is a highly virulent bacterium, however the molecular mechanisms underlying T. pallidum pathogenesis remain to be definitively identified. This is due to the fact that T. pallidum is currently uncultivatable, inherently fragile and thus difficult to work with, and phylogenetically distinct with no conventional virulence factor homologs found in other pathogens. In fact, approximately 30% of its predicted protein-coding genes have no known orthologs or assigned functions. Here we employed a structural bioinformatics approach using Phyre2-based tertiary structure modeling to improve our understanding of T. pallidum protein function on a proteome-wide scale. Results Phyre2-based tertiary structure modeling generated high-confidence predictions for 80% of the T. pallidum proteome (780/978 predicted proteins). Tertiary structure modeling also inferred the same function as primary structure-based annotations from genome sequencing pipelines for 525/605 proteins (87%), which represents 54% (525/978) of all T. pallidum proteins. Of the 175 T. pallidum proteins modeled with high confidence that were not assigned functions in the previously annotated published proteome, 167 (95%) were able to be assigned predicted functions. Twenty-one of the 175 hypothetical proteins modeled with high confidence were also predicted to exhibit significant structural similarity with proteins experimentally confirmed to be required for virulence in other pathogens. Conclusions Phyre2-based structural modeling is a powerful bioinformatics tool that has provided insight into the potential structure and function of the majority of T. pallidum proteins and helped validate the primary structure-based annotation of more than 50% of all T. pallidum proteins with high confidence. This work represents the first T. pallidum proteome-wide structural modeling study and is one of few studies to apply this approach for the functional annotation of a whole proteome. Electronic supplementary material The online version of this article (10.1186/s12900-018-0086-3) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Simon Houston
- Department of Biochemistry and Microbiology, University of Victoria, Victoria, British Columbia, Canada
| | - Karen Vivien Lithgow
- Department of Biochemistry and Microbiology, University of Victoria, Victoria, British Columbia, Canada
| | | | - Chris Richard Kenyon
- HIV/STI Unit, Institute of Tropical Medicine, Antwerp, Belgium.,Division of Infectious Diseases and HIV Medicine, University of Cape Town, Cape Town, South Africa
| | - Caroline E Cameron
- Department of Biochemistry and Microbiology, University of Victoria, Victoria, British Columbia, Canada.
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29
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Microbial and viral chitinases: Attractive biopesticides for integrated pest management. Biotechnol Adv 2018; 36:818-838. [DOI: 10.1016/j.biotechadv.2018.01.002] [Citation(s) in RCA: 50] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/20/2017] [Revised: 12/28/2017] [Accepted: 01/02/2018] [Indexed: 02/01/2023]
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30
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Dr. Alois Huger - Laying the foundations for an integrated insect pathology. J Invertebr Pathol 2016; 143:83-89. [PMID: 27871814 DOI: 10.1016/j.jip.2016.11.010] [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: 08/10/2016] [Revised: 11/16/2016] [Accepted: 11/17/2016] [Indexed: 11/21/2022]
Abstract
Dr. Rer. Nat. Alois M. Huger had a long and distinguished career at the Institut für biologische Schädlingsbekämpfung (Institute for Biological Pest Control) Darmstadt, Germany, where he became one of the world's leading insect pathologists. He applied his experience and understanding of insect tissues and specialist skills in microscopy to diagnosis and elucidation of the pathology of insect diseases. During his career he discovered the Oryctes nudivirus and Bacillus thuringiensis subsp. tenebrionis, and was a member of teams unravelling amber disease in scarab beetles and the role of bacteria in parthenogenesis of parasitoids. He researched and described the life cycles of microsporidian and rickettsial pathogens of insects and was the first to describe the ultrastructure of a microsporidian spore. Dr. Huger carried out diagnosis of diseased insects over a period of 55years and has left us with many publications and a database containing thousands of records for ongoing investigation. Working with multiple pathogens in different systems, Dr. Huger obtained an overview second to none in the complexities of insect/pathogen relationships and has been at the forefront of making these discoveries benefit humanity. He is a worthy recipient of the Founders' Lecture Honoree Award, the highest honour of the Society for Invertebrate Pathology.
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31
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Rangel LI, Henkels MD, Shaffer BT, Walker FL, Davis EW, Stockwell VO, Bruck D, Taylor BJ, Loper JE. Characterization of Toxin Complex Gene Clusters and Insect Toxicity of Bacteria Representing Four Subgroups of Pseudomonas fluorescens. PLoS One 2016; 11:e0161120. [PMID: 27580176 PMCID: PMC5006985 DOI: 10.1371/journal.pone.0161120] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/12/2016] [Accepted: 07/29/2016] [Indexed: 11/30/2022] Open
Abstract
Ten strains representing four lineages of the Pseudomonas fluorescens group (P. chlororaphis, P. corrugata, P. koreensis, and P. fluorescens subgroups) were evaluated for toxicity to the tobacco hornworm Manduca sexta and the common fruit fly Drosophila melanogaster. The three strains within the P. chlororaphis subgroup exhibited both oral and injectable toxicity to the lepidopteran M. sexta. All three strains have the gene cluster encoding the FitD insect toxin and a ΔfitD mutant of P. protegens strain Pf-5 exhibited diminished oral toxicity compared to the wildtype strain. Only one of the three strains, P. protegens Pf-5, exhibited substantial levels of oral toxicity against the dipteran D. melanogaster. Three strains in the P. fluorescens subgroup, which lack fitD, consistently showed significant levels of injectable toxicity against M. sexta. In contrast, the oral toxicity of these strains against D. melanogaster was variable between experiments, with only one strain, Pseudomonas sp. BG33R, causing significant levels of mortality in repeated experiments. Toxin complex (Tc) gene clusters, which encode insecticidal properties in Photorhabdus luminescens, were identified in the genomes of seven of the ten strains evaluated in this study. Within those seven genomes, six types of Tc gene clusters were identified, distinguished by gene content, organization and genomic location, but no correlation was observed between the presence of Tc genes and insect toxicity of the evaluated strains. Our results demonstrate that members of the P. fluorescens group have the capacity to kill insects by both FitD-dependent and independent mechanisms.
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Affiliation(s)
- Lorena I. Rangel
- Department of Botany and Plant Pathology, Oregon State University, Corvallis, Oregon, United States of America
| | - Marcella D. Henkels
- Department of Botany and Plant Pathology, Oregon State University, Corvallis, Oregon, United States of America
- Agricultural Research Service, US Department of Agriculture, Horticultural Crops Research Laboratory, Corvallis, Oregon, United States of America
| | - Brenda T. Shaffer
- Agricultural Research Service, US Department of Agriculture, Horticultural Crops Research Laboratory, Corvallis, Oregon, United States of America
| | - Francesca L. Walker
- Department of Integrative Biology, Oregon State University, Corvallis, Oregon, United States of America
| | - Edward W. Davis
- Agricultural Research Service, US Department of Agriculture, Horticultural Crops Research Laboratory, Corvallis, Oregon, United States of America
| | - Virginia O. Stockwell
- Department of Botany and Plant Pathology, Oregon State University, Corvallis, Oregon, United States of America
| | - Denny Bruck
- Agricultural Research Service, US Department of Agriculture, Horticultural Crops Research Laboratory, Corvallis, Oregon, United States of America
| | - Barbara J. Taylor
- Department of Integrative Biology, Oregon State University, Corvallis, Oregon, United States of America
| | - Joyce E. Loper
- Department of Botany and Plant Pathology, Oregon State University, Corvallis, Oregon, United States of America
- Agricultural Research Service, US Department of Agriculture, Horticultural Crops Research Laboratory, Corvallis, Oregon, United States of America
- * E-mail:
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Hurst MRH, Beattie A, Altermann E, Moraga RM, Harper LA, Calder J, Laugraud A. The Draft Genome Sequence of the Yersinia entomophaga Entomopathogenic Type Strain MH96T. Toxins (Basel) 2016; 8:toxins8050143. [PMID: 27187466 PMCID: PMC4885058 DOI: 10.3390/toxins8050143] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/24/2016] [Revised: 04/21/2016] [Accepted: 04/26/2016] [Indexed: 01/28/2023] Open
Abstract
Here we report the draft genome of Yersinia entomophaga type strain MH96T. The genome shows 93.8% nucleotide sequence identity to that of Yersinia nurmii type strain APN3a-cT, and comprises a single chromosome of approximately 4,275,531 bp. In silico analysis identified that, in addition to the previously documented Y. entomophaga Yen-TC gene cluster, the genome encodes a diverse array of toxins, including two type III secretion systems, and five rhs-associated gene clusters. As well as these multicomponent systems, several orthologs of known insect toxins, such as VIP2 toxin and the binary toxin PirAB, and distant orthologs of some mammalian toxins, including repeats-in-toxin, a cytolethal distending toxin, hemolysin-like genes and an adenylate cyclase were identified. The genome also contains a large number of hypothetical proteins and orthologs of known effector proteins, such as LopT, as well as genes encoding a wide range of proteolytic determinants, including metalloproteases and pathogen fitness determinants, such as genes involved in iron metabolism. The bioinformatic data derived from the current in silico analysis, along with previous information on the pathobiology of Y. entomophaga against its insect hosts, suggests that a number of these virulence systems are required for survival in the hemocoel and incapacitation of the insect host.
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Affiliation(s)
- Mark R H Hurst
- AgResearch, Farm Systems & Environment, Lincoln Research Centre, Christchurch 8140, New Zealand.
| | - Amy Beattie
- AgResearch, Farm Systems & Environment, Lincoln Research Centre, Christchurch 8140, New Zealand.
| | - Eric Altermann
- AgResearch Limited, Rumen Microbiology, Palmerston North 4474, New Zealand.
- Riddet Institute, Massey University, Palmerston North 4474, New Zealand.
| | - Roger M Moraga
- AgResearch Limited, Bioinformatics & Statistics, Hamilton 3214, New Zealand.
| | - Lincoln A Harper
- AgResearch, Farm Systems & Environment, Lincoln Research Centre, Christchurch 8140, New Zealand.
| | - Joanne Calder
- AgResearch, Farm Systems & Environment, Lincoln Research Centre, Christchurch 8140, New Zealand.
| | - Aurelie Laugraud
- AgResearch Limited, Bioinformatics & Statistics, Lincoln Research Centre, Christchurch 8140, New Zealand.
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Microbiome and Biocatalytic Bacteria in Monkey Cup (Nepenthes Pitcher) Digestive Fluid. Sci Rep 2016; 6:20016. [PMID: 26817720 PMCID: PMC4730220 DOI: 10.1038/srep20016] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/10/2015] [Accepted: 12/07/2015] [Indexed: 02/08/2023] Open
Abstract
Tropical carnivorous plant, Nepenthes, locally known as “monkey cup”, utilises its pitcher as a passive trap to capture insects. It then secretes enzymes into the pitcher fluid to digest the insects for nutrients acquisition. However, little is known about the microbiota and their activity in its pitcher fluid. Eighteen bacteria phyla were detected from the metagenome study in the Nepenthes pitcher fluid. Proteobacteria, Bacteroidetes and Actinobacteria are the dominant phyla in the Nepenthes pitcher fluid. We also performed culturomics approach by isolating 18 bacteria from the Nepenthes pitcher fluid. Most of the bacterial isolates possess chitinolytic, proteolytic, amylolytic, and cellulolytic and xylanolytic activities. Fifteen putative chitinase genes were identified from the whole genome analysis on the genomes of the 18 bacteria isolated from Nepenthes pitcher fluid and expressed for chitinase assay. Of these, six clones possessed chitinase activity. In conclusion, our metagenome result shows that the Nepenthes pitcher fluid contains vast bacterial diversity and the culturomic studies confirmed the presence of biocatalytic bacteria within the Nepenthes pitcher juice which may act in symbiosis for the turn over of insects trapped in the Nepenthes pitcher fluid.
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34
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Jones SA, Hurst MRH. Purification of the Yersinia entomophaga Yen-TC Toxin Complex Using Size Exclusion Chromatography. Methods Mol Biol 2016; 1477:39-48. [PMID: 27565490 DOI: 10.1007/978-1-4939-6367-6_4] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
Abstract
The Yersinia entomophaga toxin complex (Yen-TC) is the bacterium's main virulence determinant. Because of its high insect activity, methods were developed to allow the routine isolation and purification of Yen-TC from an overnight bacterial culture using size exclusion chromatography. Here we outline an overnight purification procedure using a 100-ml culture volume, where approximately 2 mg of Yen-TC, with an approximate purity of 95-98 %, can be routinely obtained.
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Affiliation(s)
- Sandra A Jones
- Innovative Farm Systems, AgResearch, Lincoln Research Centre, Canterbury, New Zealand.
| | - Mark R H Hurst
- Innovative Farm Systems, AgResearch, Lincoln Research Centre, Canterbury, New Zealand
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35
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Sheets J, Aktories K. Insecticidal Toxin Complexes from Photorhabdus luminescens. Curr Top Microbiol Immunol 2016; 402:3-23. [DOI: 10.1007/82_2016_55] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
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Temperature-Dependent Galleria mellonella Mortality as a Result of Yersinia entomophaga Infection. Appl Environ Microbiol 2015; 81:6404-14. [PMID: 26162867 DOI: 10.1128/aem.00790-15] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/12/2015] [Accepted: 06/29/2015] [Indexed: 12/28/2022] Open
Abstract
The bacterium Yersinia entomophaga is pathogenic to a range of insect species, with death typically occurring within 2 to 5 days of ingestion. Per os challenge of larvae of the greater wax moth (Galleria mellonella) confirmed that Y. entomophaga was virulent when fed to larvae held at 25°C but was avirulent when fed to larvae maintained at 37°C. At 25°C, a dose of ~4 × 10(7) CFU per larva of a Y. entomophaga toxin complex (Yen-TC) deletion derivative, the Y. entomophaga ΔTC variant, resulted in 27% mortality. This low level of activity was restored to near-wild-type levels by augmentation of the diet with a sublethal dose of purified Yen-TC. Intrahemocoelic injection of ~3 Y. entomophaga or Y. entomophaga ΔTC cells per larva gave a 4-day median lethal dose, with similar levels of mortality observed at both 25 and 37°C. Following intrahemocoelic injection of a Yen-TC YenA1 green fluorescent protein fusion strain into larvae maintained at 25°C, the bacteria did not fluoresce until the population density reached 2 × 10(7) CFU ml(-1) of hemolymph. The observed cells also took an irregular form. When the larvae were maintained at 37°C, the cells were small and the observed fluorescence was sporadic and weak, being more consistent at a population density of ~3 × 10(9) CFU ml(-1) of hemolymph. These findings provide further understanding of the pathobiology of Y. entomophaga in insects, showing that the bacterium gains direct access to the hemocoelic cavity, from where it rapidly multiplies to cause disease.
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Insect Pathogenic Bacteria in Integrated Pest Management. INSECTS 2015; 6:352-67. [PMID: 26463190 PMCID: PMC4553484 DOI: 10.3390/insects6020352] [Citation(s) in RCA: 64] [Impact Index Per Article: 7.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Subscribe] [Scholar Register] [Received: 02/25/2015] [Revised: 04/01/2015] [Accepted: 04/08/2015] [Indexed: 11/24/2022]
Abstract
The scientific community working in the field of insect pathology is experiencing an increasing academic and industrial interest in the discovery and development of new bioinsecticides as environmentally friendly pest control tools to be integrated, in combination or rotation, with chemicals in pest management programs. In this scientific context, market data report a significant growth of the biopesticide segment. Acquisition of new technologies by multinational Ag-tech companies is the center of the present industrial environment. This trend is in line with the requirements of new regulations on Integrated Pest Management. After a few decades of research on microbial pest management dominated by Bacillus thuringiensis (Bt), novel bacterial species with innovative modes of action are being discovered and developed into new products. Significant cases include the entomopathogenic nematode symbionts Photorhabdus spp. and Xenorhabdus spp., Serratia species, Yersinia entomophaga, Pseudomonas entomophila, and the recently discovered Betaproteobacteria species Burkholderia spp. and Chromobacterium spp. Lastly, Actinobacteria species like Streptomyces spp. and Saccharopolyspora spp. have gained high commercial interest for the production of a variety of metabolites acting as potent insecticides. With the aim to give a timely picture of the cutting-edge advancements in this renewed research field, different representative cases are reported and discussed.
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Chen WJ, Hsieh FC, Hsu FC, Tasy YF, Liu JR, Shih MC. Characterization of an insecticidal toxin and pathogenicity of Pseudomonas taiwanensis against insects. PLoS Pathog 2014; 10:e1004288. [PMID: 25144637 PMCID: PMC4140846 DOI: 10.1371/journal.ppat.1004288] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/07/2014] [Accepted: 06/17/2014] [Indexed: 01/28/2023] Open
Abstract
Pseudomonas taiwanensis is a broad-host-range entomopathogenic bacterium that exhibits insecticidal activity toward agricultural pests Plutella xylostella, Spodoptera exigua, Spodoptera litura, Trichoplusia ni and Drosophila melanogaster. Oral infection with different concentrations (OD = 0.5 to 2) of wild-type P. taiwanensis resulted in insect mortality rates that were not significantly different (92.7%, 96.4% and 94.5%). The TccC protein, a component of the toxin complex (Tc), plays an essential role in the insecticidal activity of P. taiwanensis. The ΔtccC mutant strain of P. taiwanensis, which has a knockout mutation in the tccC gene, only induced 42.2% mortality in P. xylostella, even at a high bacterial dose (OD = 2.0). TccC protein was cleaved into two fragments, an N-terminal fragment containing an Rhs-like domain and a C-terminal fragment containing a Glt symporter domain and a TraT domain, which might contribute to antioxidative stress activity and defense against macrophagosis, respectively. Interestingly, the primary structure of the C-terminal region of TccC in P. taiwanensis is unique among pathogens. Membrane localization of the C-terminal fragment of TccC was proven by flow cytometry. Sonicated pellets of P. taiwanensis ΔtccC strain had lower toxicity against the Sf9 insect cell line and P. xylostella larvae than the wild type. We also found that infection of Sf9 and LD652Y-5d cell lines with P. taiwanensis induced apoptotic cell death. Further, natural oral infection by P. taiwanensis triggered expression of host programmed cell death-related genes JNK-2 and caspase-3.
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Affiliation(s)
- Wen-Jen Chen
- Institute of Biotechnology, National Taiwan University, Taipei, Taiwan; Agricultural Biotechnology Research Center, Academia Sinica, Taipei, Taiwan
| | - Feng-Chia Hsieh
- Biopesticide Division, Taiwan Agricultural Chemicals and Toxic Substances Research Institute, Council of Agriculture, Taichung, Taiwan
| | - Fu-Chiun Hsu
- Institute of Molecular Biology, Academia Sinica, Taipei, Taiwan
| | - Yi-Fang Tasy
- Institute of Molecular Biology, Academia Sinica, Taipei, Taiwan
| | - Je-Ruei Liu
- Institute of Biotechnology, National Taiwan University, Taipei, Taiwan; Agricultural Biotechnology Research Center, Academia Sinica, Taipei, Taiwan
| | - Ming-Che Shih
- Institute of Biotechnology, National Taiwan University, Taipei, Taiwan; Agricultural Biotechnology Research Center, Academia Sinica, Taipei, Taiwan
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Shyntum DY, Venter SN, Moleleki LN, Toth I, Coutinho TA. Comparative genomics of type VI secretion systems in strains of Pantoea ananatis from different environments. BMC Genomics 2014; 15:163. [PMID: 24571088 PMCID: PMC3942780 DOI: 10.1186/1471-2164-15-163] [Citation(s) in RCA: 33] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/15/2013] [Accepted: 02/18/2014] [Indexed: 11/25/2022] Open
Abstract
BACKGROUND The Type VI secretion system (T6SS) has been identified in several different bacteria, including the plant pathogenPantoea ananatis. Previous in silico analyses described three different T6SS loci present in the pathogenic strain of P. ananatis LMG 20103. This initial investigation has been extended to include an additional seven sequenced strains of P. ananatis together with 39 strains from different ecological niches. Comparative and phylogenetic analyses were used to investigate the distribution, evolution, intra-strain variability and operon structure of the T6SS in the sequenced strains. RESULTS Three different T6SS loci were identified in P. ananatis strain LMG 20103 and designated PA T6SS 1-3. PA T6SS-1 was present in all sequenced strains of P. ananatis and in all 39 additional strains examined in this study. In addition, PA T6SS-1 included all 13 core T6SS genes required for synthesis of a functional T6SS. The plasmid-borne PA T6SS-2 also included all 13 core T6SS genes but was restricted to only 33% (15/46) of the strains examined. In addition, PA T6SS-2 was restricted to strains of P. ananatis isolated from symptomatic plant material. This finding raises the possibility of an association between PA T6SS-2 and either pathogenicity or host specificity. The third cluster PA T6SS-3 was present in all strains analyzed in this study but lacked 11 of the 13 core T6SS genes suggesting it may not encoded a functional T6SS. Inter-strain variability was also associated with hcp and vgrG islands, which are associated with the T6SS and encode a variable number of proteins usually of unknown function. These proteins may play a role in the fitness of different strains in a variety of ecological niches or as candidate T6SS effectors. Phylogenetic analysis indicated that PA T6SS-1 and PA T6SS-2 are evolutionarily distinct. CONCLUSION Our analysis indicates that the three T6SSs of P. ananatis appear to have been independently acquired and may play different roles relating to pathogenicity, host range determination and/or niche adaptation. Future work will be directed toward understanding the roles that these T6SSs play in the biology of P. ananatis.
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Affiliation(s)
- Divine Yufetar Shyntum
- Department of Microbiology and Plant Pathology, Forestry and Agricultural Biotechnology Institute (FABI), University of Pretoria, Pretoria, South Africa
| | - Stephanus Nicolaas Venter
- Department of Microbiology and Plant Pathology, Forestry and Agricultural Biotechnology Institute (FABI), University of Pretoria, Pretoria, South Africa
| | - Lucy Novungayo Moleleki
- Department of Microbiology and Plant Pathology, Forestry and Agricultural Biotechnology Institute (FABI), University of Pretoria, Pretoria, South Africa
| | - Ian Toth
- Department of Microbiology and Plant Pathology, Forestry and Agricultural Biotechnology Institute (FABI), University of Pretoria, Pretoria, South Africa
- James Hutton Research Institute, Invergowrie, Dundee DD2 5DA, Scotland, UK
| | - Teresa Ann Coutinho
- Department of Microbiology and Plant Pathology, Forestry and Agricultural Biotechnology Institute (FABI), University of Pretoria, Pretoria, South Africa
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Castagnola A, Stock SP. Common Virulence Factors and Tissue Targets of Entomopathogenic Bacteria for Biological Control of Lepidopteran Pests. INSECTS 2014; 5:139-66. [PMID: 24634779 PMCID: PMC3952272 DOI: 10.3390/insects5010139] [Citation(s) in RCA: 42] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Subscribe] [Scholar Register] [Received: 09/22/2013] [Revised: 12/13/2013] [Accepted: 12/17/2013] [Indexed: 01/13/2023]
Abstract
This review focuses on common insecticidal virulence factors from entomopathogenic bacteria with special emphasis on two insect pathogenic bacteria Photorhabdus (Proteobacteria: Enterobacteriaceae) and Bacillus (Firmicutes: Bacillaceae). Insect pathogenic bacteria of diverse taxonomic groups and phylogenetic origin have been shown to have striking similarities in the virulence factors they produce. It has been suggested that the detection of phage elements surrounding toxin genes, horizontal and lateral gene transfer events, and plasmid shuffling occurrences may be some of the reasons that virulence factor genes have so many analogs throughout the bacterial kingdom. Comparison of virulence factors of Photorhabdus, and Bacillus, two bacteria with dissimilar life styles opens the possibility of re-examining newly discovered toxins for novel tissue targets. For example, nematodes residing in the hemolymph may release bacteria with virulence factors targeting neurons or neuromuscular junctions. The first section of this review focuses on toxins and their context in agriculture. The second describes the mode of action of toxins from common entomopathogens and the third draws comparisons between Gram positive and Gram negative bacteria. The fourth section reviews the implications of the nervous system in biocontrol.
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Affiliation(s)
- Anaïs Castagnola
- Center for Insect Science, University of Arizona, 1007 E. Lowell Street, Tucson, AZ 85721, USA; E-Mail:
| | - S. Patricia Stock
- Department of Entomology, University of Arizona, 1140 E. South Campus Dr., Tucson, AZ 85721, USA
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Hurst MRH, van Koten C, Jackson TA. Pathology of Yersinia entomophaga MH96 towards Costelytra zealandica (Coleoptera; Scarabaeidae) larvae. J Invertebr Pathol 2014; 115:102-7. [DOI: 10.1016/j.jip.2013.11.004] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/03/2013] [Revised: 10/15/2013] [Accepted: 11/21/2013] [Indexed: 11/30/2022]
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Role of Yersinia pestis toxin complex family proteins in resistance to phagocytosis by polymorphonuclear leukocytes. Infect Immun 2013; 81:4041-52. [PMID: 23959716 DOI: 10.1128/iai.00648-13] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022] Open
Abstract
Yersinia pestis carries homologues of the toxin complex (Tc) family proteins, which were first identified in other Gram-negative bacteria as having potent insecticidal activity. The Y. pestis Tc proteins are neither toxic to fleas nor essential for survival of the bacterium in the flea, even though tc gene expression is highly upregulated and much more of the Tc proteins YitA and YipA are produced in the flea than when Y. pestis is grown in vitro. We show that Tc(+) and Tc(-) Y. pestis strains are transmitted equivalently from coinfected fleas, further demonstrating that the Tc proteins have no discernible role, either positive or negative, in transmission by the flea vector. Tc proteins did, however, confer Y. pestis with increased resistance to killing by polymorphonuclear leukocytes (PMNs). Resistance to killing was not the result of decreased PMN viability or increased intracellular survival but instead correlated with a Tc protein-dependent resistance to phagocytosis that was independent of the type III secretion system (T3SS). Correspondingly, we did not detect T3SS-dependent secretion of the native Tc proteins YitA and YipA or the translocation of YitA- or YipA-β-lactamase fusion proteins into CHO-K1 (CHO) cells or human PMNs. Thus, although highly produced by Y. pestis within the flea and related to insecticidal toxins, the Tc proteins do not affect interaction with the flea or transmission. Rather, the Y. pestis Tc proteins inhibit phagocytosis by mouse PMNs, independent of the T3SS, and may be important for subverting the mammalian innate immune response immediately following transmission from the flea.
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Busby JN, Panjikar S, Landsberg MJ, Hurst MRH, Lott JS. The BC component of ABC toxins is an RHS-repeat-containing protein encapsulation device. Nature 2013; 501:547-50. [PMID: 23913273 DOI: 10.1038/nature12465] [Citation(s) in RCA: 96] [Impact Index Per Article: 8.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/25/2013] [Accepted: 07/16/2013] [Indexed: 12/20/2022]
Abstract
The ABC toxin complexes produced by certain bacteria are of interest owing to their potent insecticidal activity and potential role in human disease. These complexes comprise at least three proteins (A, B and C), which must assemble to be fully toxic. The carboxy-terminal region of the C protein is the main cytotoxic component, and is poorly conserved between different toxin complexes. A general model of action has been proposed, in which the toxin complex binds to the cell surface via the A protein, is endocytosed, and subsequently forms a pH-triggered channel, allowing the translocation of C into the cytoplasm, where it can cause cytoskeletal disruption in both insect and mammalian cells. Toxin complexes have been visualized using single-particle electron microscopy, but no high-resolution structures of the components are available, and the role of the B protein in the mechanism of toxicity remains unknown. Here we report the three-dimensional structure of the complex formed between the B and C proteins, determined to 2.5 Å by X-ray crystallography. These proteins assemble to form an unprecedented, large hollow structure that encapsulates and sequesters the cytotoxic, C-terminal region of the C protein like the shell of an egg. The shell is decorated on one end by a β-propeller domain, which mediates attachment of the B-C heterodimer to the A protein in the native complex. The structure reveals how C auto-proteolyses when folded in complex with B. The C protein is the first example, to our knowledge, of a structure that contains rearrangement hotspot (RHS) repeats, and illustrates a marked structural architecture that is probably conserved across both this widely distributed bacterial protein family and the related eukaryotic tyrosine-aspartate (YD)-repeat-containing protein family, which includes the teneurins. The structure provides the first clues about the function of these protein repeat families, and suggests a generic mechanism for protein encapsulation and delivery.
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Affiliation(s)
- Jason N Busby
- AgResearch Structural Biology Laboratory, School of Biological Sciences, The University of Auckland, Auckland 1142, New Zealand
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Starke M, Richter M, Fuchs TM. The insecticidal toxin genes ofYersinia enterocoliticaare activated by the thermolabile LTTR-like regulator TcaR2 at low temperatures. Mol Microbiol 2013; 89:596-611. [DOI: 10.1111/mmi.12296] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 06/12/2013] [Indexed: 11/28/2022]
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Physiological levels of glucose induce membrane vesicle secretion and affect the lipid and protein composition of Yersinia pestis cell surfaces. Appl Environ Microbiol 2013; 79:4509-14. [PMID: 23686263 DOI: 10.1128/aem.00675-13] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Yersinia pestis grown with physiologic glucose increased cell autoaggregation and deposition of extracellular material, including membrane vesicles. Membranes were characterized, and glucose had significant effects on protein, lipid, and carbohydrate profiles. These effects were independent of temperature and the biofilm-related locus pgm and were not observed in Yersinia pseudotuberculosis.
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Marshall SDG, Hares MC, Jones SA, Harper LA, Vernon JR, Harland DP, Jackson TA, Hurst MRH. Histopathological effects of the Yen-Tc toxin complex from Yersinia entomophaga MH96 (Enterobacteriaceae) on the Costelytra zealandica (Coleoptera: Scarabaeidae) larval midgut. Appl Environ Microbiol 2012; 78:4835-47. [PMID: 22544254 PMCID: PMC3416359 DOI: 10.1128/aem.00431-12] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/12/2012] [Accepted: 04/21/2012] [Indexed: 12/11/2022] Open
Abstract
Yersinia entomophaga MH96, which was originally isolated from the New Zealand grass grub, Costelytra zealandica, produces an orally active proteinaceous toxin complex (Yen-Tc), and this toxin is responsible for mortality in a range of insect species, mainly within the Coleoptera and Lepidoptera. The genes encoding Yen-Tc are members of the toxin complex (Tc) family, with orthologs identified in several other bacterial species. As the mechanism of Yen-Tc activity remains unknown, a histopathological examination of C. zealandica larvae was undertaken in conjunction with cultured cells to identify the effects of Yen-Tc and to distinguish the contributions that its individual subunit components make upon intoxication. A progressive series of events that led to the deterioration of the midgut epithelium was observed. Additionally, experiments using a cell culture assay system were carried out to determine the cellular effects of intoxication on cells after topical application and the transient expression of Yen-Tc and its individual components. While observations were broadly consistent with those previously reported for other Tc family members, some differences were noted. In particular, the distinct stepwise disintegration of the midgut shared features associated with both apoptosis and necrotic programmed cell death pathways. Second, we observed, for the first time, a contribution of toxicity from two chitinases associated with the Yen-Tc complex. Our findings were suggestive of the activities encoded within the subunit components of Yen-Tc targeting different sites along putative programmed cell death pathways. Given the observed broad host range for Yen-Tc, these targeted loci are likely to be widely shared among insects.
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Affiliation(s)
- Sean D G Marshall
- AgResearch, Innovative Farm Systems, Lincoln Research Centre, Christchurch, New Zealand.
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Yersinia--flea interactions and the evolution of the arthropod-borne transmission route of plague. Curr Opin Microbiol 2012; 15:239-46. [PMID: 22406208 DOI: 10.1016/j.mib.2012.02.003] [Citation(s) in RCA: 54] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/19/2012] [Revised: 02/14/2012] [Accepted: 02/16/2012] [Indexed: 02/06/2023]
Abstract
Yersinia pestis, the causative agent of plague, is unique among the enteric group of Gram-negative bacteria in relying on a blood-feeding insect for transmission. The Yersinia-flea interactions that enable plague transmission cycles have had profound historical consequences as manifested by human plague pandemics. The arthropod-borne transmission route was a radical ecologic change from the food-borne and water-borne transmission route of Yersinia pseudotuberculosis, from which Y. pestis diverged only within the last 20000 years. Thus, the interactions of Y. pestis with its flea vector that lead to colonization and successful transmission are the result of a recent evolutionary adaptation that required relatively few genetic changes. These changes from the Y. pseudotuberculosis progenitor included loss of insecticidal activity, increased resistance to antibacterial factors in the flea midgut, and extending Yersinia biofilm-forming ability to the flea host environment.
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Structural Analysis of Chi1 Chitinase from Yen-Tc: The Multisubunit Insecticidal ABC Toxin Complex of Yersinia entomophaga. J Mol Biol 2012; 415:359-71. [DOI: 10.1016/j.jmb.2011.11.018] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/23/2011] [Revised: 11/03/2011] [Accepted: 11/08/2011] [Indexed: 10/15/2022]
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Landsberg MJ, Jones SA, Rothnagel R, Busby JN, Marshall SDG, Simpson RM, Lott JS, Hankamer B, Hurst MRH. 3D structure of the Yersinia entomophaga toxin complex and implications for insecticidal activity. Proc Natl Acad Sci U S A 2011; 108:20544-9. [PMID: 22158901 PMCID: PMC3251104 DOI: 10.1073/pnas.1111155108] [Citation(s) in RCA: 61] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/13/2023] Open
Abstract
Toxin complex (Tc) proteins are a class of bacterial protein toxins that form large, multisubunit complexes. Comprising TcA, B, and C components, they are of great interest because many exhibit potent insecticidal activity. Here we report the structure of a novel Tc, Yen-Tc, isolated from the bacterium Yersinia entomophaga MH96, which differs from the majority of bacterially derived Tcs in that it exhibits oral activity toward a broad range of insect pests, including the diamondback moth (Plutella xylostella). We have determined the structure of the Yen-Tc using single particle electron microscopy and studied its mechanism of toxicity by comparative analyses of two variants of the complex exhibiting different toxicity profiles. We show that the A subunits form the basis of a fivefold symmetric assembly that differs substantially in structure and subunit arrangement from its most well characterized homologue, the Xenorhabdus nematophila toxin XptA1. Histopathological and quantitative dose response analyses identify the B and C subunits, which map to a single, surface-accessible region of the structure, as the sole determinants of toxicity. Finally, we show that the assembled Yen-Tc has endochitinase activity and attribute this to putative chitinase subunits that decorate the surface of the TcA scaffold, an observation that may explain the oral toxicity associated with the complex.
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Affiliation(s)
- Michael J. Landsberg
- Institute for Molecular Bioscience, University of Queensland, St. Lucia, Queensland 4072, Australia
| | - Sandra A. Jones
- Innovative Farming Systems, AgResearch, Lincoln Research Centre, Christchurch 8140, New Zealand
| | - Rosalba Rothnagel
- Institute for Molecular Bioscience, University of Queensland, St. Lucia, Queensland 4072, Australia
| | - Jason N. Busby
- AgResearch Structural Biology Laboratory, School of Biological Sciences, University of Auckland, Auckland 1142, New Zealand; and
| | - Sean D. G. Marshall
- Innovative Farming Systems, AgResearch, Lincoln Research Centre, Christchurch 8140, New Zealand
| | - Robert M. Simpson
- New Zealand Institute for Plant and Food Research, Palmerston North 4474, New Zealand
| | - J. Shaun Lott
- AgResearch Structural Biology Laboratory, School of Biological Sciences, University of Auckland, Auckland 1142, New Zealand; and
| | - Ben Hankamer
- Institute for Molecular Bioscience, University of Queensland, St. Lucia, Queensland 4072, Australia
| | - Mark R. H. Hurst
- Innovative Farming Systems, AgResearch, Lincoln Research Centre, Christchurch 8140, New Zealand
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