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Martin CL, Hill JH, Aller SG. Host Tropism and Structural Biology of ABC Toxin Complexes. Toxins (Basel) 2024; 16:406. [PMID: 39330864 PMCID: PMC11435725 DOI: 10.3390/toxins16090406] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/21/2024] [Revised: 09/12/2024] [Accepted: 09/17/2024] [Indexed: 09/28/2024] Open
Abstract
ABC toxin complexes are a class of protein toxin translocases comprised of a multimeric assembly of protein subunits. Each subunit displays a unique composition, contributing to the formation of a syringe-like nano-machine with natural cargo carrying, targeting, and translocation capabilities. Many of these toxins are insecticidal, drawing increasing interest in agriculture for use as biological pesticides. The A subunit (TcA) is the largest subunit of the complex and contains domains associated with membrane permeation and targeting. The B and C subunits, TcB and TcC, respectively, package into a cocoon-like structure that contains a toxic peptide and are coupled to TcA to form a continuous channel upon final assembly. In this review, we outline the current understanding and gaps in the knowledge pertaining to ABC toxins, highlighting seven published structures of TcAs and how these structures have led to a better understanding of the mechanism of host tropism and toxin translocation. We also highlight similarities and differences between homologues that contribute to variations in host specificity and conformational change. Lastly, we review the biotechnological potential of ABC toxins as both pesticides and cargo-carrying shuttles that enable the transport of peptides into cells.
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Affiliation(s)
- Cole L Martin
- Graduate Biomedical Sciences Pathobiology, Physiology and Pharmacology Theme, University of Alabama at Birmingham, Birmingham, AL 35294, USA
- Department of Pharmacology and Toxicology, University of Alabama at Birmingham, Birmingham, AL 35294, USA
| | - John H Hill
- Department of Pharmacology and Toxicology, University of Alabama at Birmingham, Birmingham, AL 35294, USA
| | - Stephen G Aller
- Department of Pharmacology and Toxicology, University of Alabama at Birmingham, Birmingham, AL 35294, USA
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2
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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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3
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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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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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Mi L, Gu Z, Li Y, Xu W, Shu C, Zhang J, Bai X, Geng L. Enterobacter Strain IPPBiotE33 Displays a Synergistic Effect with Bacillus thuringiensis Bt185. Int J Mol Sci 2023; 24:14193. [PMID: 37762496 PMCID: PMC10531557 DOI: 10.3390/ijms241814193] [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: 08/04/2023] [Revised: 09/08/2023] [Accepted: 09/08/2023] [Indexed: 09/29/2023] Open
Abstract
The discovery and isolation of new non-Bt insecticidal bacteria and genes are significant for the development of new biopesticides against coleopteran pests. In this study, we evaluated the insecticidal activity of non-Bt insecticidal bacteria, PPBiotE33, IPPBiotC41, IPPBiotA42 and IPPBiotC43, isolated from the peanut rhizosphere. All these strains showed insecticidal activity against first- and third-instar larvae of Holotrichia parallela, Holotrichia oblita, Anomala corpulenta and Potosia brevitarsis. IPPBiotE33 showed the highest toxicity among the four strains and exhibited virulence against Colaphellus bowringi. The genome of IPPBiotE33 was sequenced, and a new protein, 03673, with growth inhibition effects on C. bowringi was obtained. In addition, IPPBiotE33 had a synergistic effect with Bacillus thuringiensis Bt185 against H. parallela in bioassays and back-inoculation experiments with peanut seedlings. IPPBiotE33 induced a decrease in hemocytes and an increase in phenol oxidase activity in H. parallela hemolymph, known as the immunosuppressive effect, which mediated synergistic activity with Bt185. This study increased our knowledge of the new insecticidal strain IPPBiotE33 and shed new light on the research on new insecticidal coaction mechanisms and new blended pesticides.
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Affiliation(s)
- Liang Mi
- State Key Laboratory for Biology of Plant Diseases and Insect Pests, Institute of Plant Protection, Chinese Academy of Agricultural Sciences, Beijing 100193, China
- College of Life Sciences, Northeast Agricultural University, Harbin 150038, China
| | - Ziqiong Gu
- State Key Laboratory for Biology of Plant Diseases and Insect Pests, Institute of Plant Protection, Chinese Academy of Agricultural Sciences, Beijing 100193, China
| | - Ying Li
- State Key Laboratory for Biology of Plant Diseases and Insect Pests, Institute of Plant Protection, Chinese Academy of Agricultural Sciences, Beijing 100193, China
| | - Wenyue Xu
- State Key Laboratory for Biology of Plant Diseases and Insect Pests, Institute of Plant Protection, Chinese Academy of Agricultural Sciences, Beijing 100193, China
| | - Changlong Shu
- State Key Laboratory for Biology of Plant Diseases and Insect Pests, Institute of Plant Protection, Chinese Academy of Agricultural Sciences, Beijing 100193, China
| | - Jie Zhang
- State Key Laboratory for Biology of Plant Diseases and Insect Pests, Institute of Plant Protection, Chinese Academy of Agricultural Sciences, Beijing 100193, China
| | - Xi Bai
- College of Life Sciences, Northeast Agricultural University, Harbin 150038, China
| | - Lili Geng
- State Key Laboratory for Biology of Plant Diseases and Insect Pests, Institute of Plant Protection, Chinese Academy of Agricultural Sciences, Beijing 100193, China
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Martin CL, Chester DW, Radka CD, Pan L, Yang Z, Hart RC, Binshtein EM, Wang Z, Nagy L, DeLucas LJ, Aller SG. Structures of the Insecticidal Toxin Complex Subunit XptA2 Highlight Roles for Flexible Domains. Int J Mol Sci 2023; 24:13221. [PMID: 37686027 PMCID: PMC10487846 DOI: 10.3390/ijms241713221] [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: 07/31/2023] [Revised: 08/18/2023] [Accepted: 08/20/2023] [Indexed: 09/10/2023] Open
Abstract
The Toxin Complex (Tc) superfamily consists of toxin translocases that contribute to the targeting, delivery, and cytotoxicity of certain pathogenic Gram-negative bacteria. Membrane receptor targeting is driven by the A-subunit (TcA), which comprises IgG-like receptor binding domains (RBDs) at the surface. To better understand XptA2, an insect specific TcA secreted by the symbiont X. nematophilus from the intestine of entomopathogenic nematodes, we determined structures by X-ray crystallography and cryo-EM. Contrary to a previous report, XptA2 is pentameric. RBD-B exhibits an indentation from crystal packing that indicates loose association with the shell and a hotspot for possible receptor binding or a trigger for conformational dynamics. A two-fragment XptA2 lacking an intact linker achieved the folded pre-pore state like wild type (wt), revealing no requirement of the linker for protein folding. The linker is disordered in all structures, and we propose it plays a role in dynamics downstream of the initial pre-pore state.
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Affiliation(s)
- Cole L. Martin
- Department of Pharmacology & Toxicology, University of Alabama at Birmingham, Birmingham, AL 35205, USA; (C.L.M.); (D.W.C.); (C.D.R.); (L.P.)
| | - David W. Chester
- Department of Pharmacology & Toxicology, University of Alabama at Birmingham, Birmingham, AL 35205, USA; (C.L.M.); (D.W.C.); (C.D.R.); (L.P.)
| | - Christopher D. Radka
- Department of Pharmacology & Toxicology, University of Alabama at Birmingham, Birmingham, AL 35205, USA; (C.L.M.); (D.W.C.); (C.D.R.); (L.P.)
- Department of Microbiology, Immunology, and Molecular Genetics, University of Kentucky, Lexington, KY 40536, USA
| | - Lurong Pan
- Department of Pharmacology & Toxicology, University of Alabama at Birmingham, Birmingham, AL 35205, USA; (C.L.M.); (D.W.C.); (C.D.R.); (L.P.)
| | - Zhengrong Yang
- Department of Biochemistry & Molecular Genetics, University of Alabama at Birmingham, Birmingham, AL 35205, USA;
| | - Rachel C. Hart
- Department of Pathology, Microbiology & Immunology, Vanderbilt University Medical Center, Nashville, TN 37232, USA; (R.C.H.); (E.M.B.)
| | - Elad M. Binshtein
- Department of Pathology, Microbiology & Immunology, Vanderbilt University Medical Center, Nashville, TN 37232, USA; (R.C.H.); (E.M.B.)
| | - Zhao Wang
- Biochemistry & Molecular Pharmacology, Cryo-Electron Microscopy and Tomography Core, Baylor College of Medicine, Houston, TX 77030, USA;
| | - Lisa Nagy
- Department of Mathematics, Engineering & Physical Sciences, Jefferson State Community College, Jefferson Campus, Birmingham, AL 35215, USA;
| | - Lawrence J. DeLucas
- Predictive Oncology Inc., 200 Riverhills Business Park, Suite 250, Birmingham, AL 35242, USA;
| | - Stephen G. Aller
- Department of Pharmacology & Toxicology, University of Alabama at Birmingham, Birmingham, AL 35205, USA; (C.L.M.); (D.W.C.); (C.D.R.); (L.P.)
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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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Malomane MT, Kondiah K, Serepa-Dlamini MH. Genetic Engineering of Escherichia coli BL21 (DE3) with a codon-optimized insecticidal toxin complex gene tccZ. Access Microbiol 2023; 5:acmi000426. [PMID: 36860507 PMCID: PMC9968953 DOI: 10.1099/acmi.0.000426] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/09/2022] [Accepted: 12/19/2022] [Indexed: 01/26/2023] Open
Abstract
A toxin complex consists of a high-molecular-weight group of toxins that exhibits insecticidal activity against insect pests. These toxins are a promising alternative to Bacillus thuringiensis (Bt) toxins that have been extensively utilized in insect pest control. Herein, a codon-optimized insecticidal gene (tccZ) (381 bp) identified in Pantoea ananatis strain MHSD5 (a bacterial endophyte previously isolated from Pellaea calomelanos) was ligated into the pET SUMO expression vector and expressed in Escherichia coli BL21 (DE3). We report the success of cloning the tccZ gene into the pET SUMO vector and ultimately the transformation into E. coli BL21 (DE3) competent cells. However, despite conducting a time course of expression as well as isopropyl β-d-1-thiogalactopyranoside (IPTG) dosage optimization to determine optimal conditions for expression, TccZ protein expression could not be detected on Stain-Free and Coomassie-stained SDS-PAGE gels.
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Affiliation(s)
- Mosibudi Thabiki Malomane
- Department of Biotechnology and Food Technology, Faculty of Science, University of Johannesburg, Doornfontein Campus, PO Box 17011, Doornfontein 2028, Johannesburg, South Africa
| | - Kulsum Kondiah
- Department of Biotechnology and Food Technology, Faculty of Science, University of Johannesburg, Doornfontein Campus, PO Box 17011, Doornfontein 2028, Johannesburg, South Africa
- *Correspondence: Kulsum Kondiah,
| | - Mahloro Hope Serepa-Dlamini
- Department of Biotechnology and Food Technology, Faculty of Science, University of Johannesburg, Doornfontein Campus, PO Box 17011, Doornfontein 2028, Johannesburg, South Africa
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Sänger PA, Wagner S, Liebler-Tenorio EM, Fuchs TM. Dissecting the invasion of Galleria mellonella by Yersinia enterocolitica reveals metabolic adaptations and a role of a phage lysis cassette in insect killing. PLoS Pathog 2022; 18:e1010991. [PMID: 36399504 PMCID: PMC9718411 DOI: 10.1371/journal.ppat.1010991] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/30/2022] [Revised: 12/02/2022] [Accepted: 11/08/2022] [Indexed: 11/19/2022] Open
Abstract
The human pathogen Yersinia enterocolitica strain W22703 is characterized by its toxicity towards invertebrates that requires the insecticidal toxin complex (Tc) proteins encoded by the pathogenicity island Tc-PAIYe. Molecular and pathophysiological details of insect larvae infection and killing by this pathogen, however, have not been dissected. Here, we applied oral infection of Galleria mellonella (Greater wax moth) larvae to study the colonisation, proliferation, tissue invasion, and killing activity of W22703. We demonstrated that this strain is strongly toxic towards the larvae, in which they proliferate by more than three orders of magnitude within six days post infection. Deletion mutants of the genes tcaA and tccC were atoxic for the insect. W22703 ΔtccC, in contrast to W22703 ΔtcaA, initially proliferated before being eliminated from the host, thus confirming TcaA as membrane-binding Tc subunit and TccC as cell toxin. Time course experiments revealed a Tc-dependent infection process starting with midgut colonisation that is followed by invasion of the hemolymph where the pathogen elicits morphological changes of hemocytes and strongly proliferates. The in vivo transcriptome of strain W22703 shows that the pathogen undergoes a drastic reprogramming of central cell functions and gains access to numerous carbohydrate and amino acid resources within the insect. Strikingly, a mutant lacking a phage-related holin/endolysin (HE) cassette, which is located within Tc-PAIYe, resembled the phenotypes of W22703 ΔtcaA, suggesting that this dual lysis cassette may be an example of a phage-related function that has been adapted for the release of a bacterial toxin.
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Affiliation(s)
| | - Stefanie Wagner
- Friedrich-Loeffler-Institut, Institut für Molekulare Pathogenese, Jena, Germany
| | | | - Thilo M. Fuchs
- Friedrich-Loeffler-Institut, Institut für Molekulare Pathogenese, Jena, Germany
- * E-mail:
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10
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CRISPR screens in Drosophila cells identify Vsg as a Tc toxin receptor. Nature 2022; 610:349-355. [PMID: 36171290 PMCID: PMC9631961 DOI: 10.1038/s41586-022-05250-7] [Citation(s) in RCA: 9] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/08/2021] [Accepted: 08/18/2022] [Indexed: 11/08/2022]
Abstract
Entomopathogenic nematodes are widely used as biopesticides1,2. Their insecticidal activity depends on symbiotic bacteria such as Photorhabdus luminescens, which produces toxin complex (Tc) toxins as major virulence factors3-6. No protein receptors are known for any Tc toxins, which limits our understanding of their specificity and pathogenesis. Here we use genome-wide CRISPR-Cas9-mediated knockout screening in Drosophila melanogaster S2R+ cells and identify Visgun (Vsg) as a receptor for an archetypal P. luminescens Tc toxin (pTc). The toxin recognizes the extracellular O-glycosylated mucin-like domain of Vsg that contains high-density repeats of proline, threonine and serine (HD-PTS). Vsg orthologues in mosquitoes and beetles contain HD-PTS and can function as pTc receptors, whereas orthologues without HD-PTS, such as moth and human versions, are not pTc receptors. Vsg is expressed in immune cells, including haemocytes and fat body cells. Haemocytes from Vsg knockout Drosophila are resistant to pTc and maintain phagocytosis in the presence of pTc, and their sensitivity to pTc is restored through the transgenic expression of mosquito Vsg. Last, Vsg knockout Drosophila show reduced bacterial loads and lethality from P. luminescens infection. Our findings identify a proteinaceous Tc toxin receptor, reveal how Tc toxins contribute to P. luminescens pathogenesis, and establish a genome-wide CRISPR screening approach for investigating insecticidal toxins and pathogens.
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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; 14:646. [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
| | - Qinying Wang
- College of Plant Protection, Hebei Agricultural University, Baoding 071000, China
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12
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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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13
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Szabó G, Schulz F, Manzano-Marín A, Toenshoff ER, Horn M. Evolutionarily recent dual obligatory symbiosis among adelgids indicates a transition between fungus- and insect-associated lifestyles. THE ISME JOURNAL 2022; 16:247-256. [PMID: 34294881 PMCID: PMC8692619 DOI: 10.1038/s41396-021-01056-z] [Citation(s) in RCA: 10] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 10/21/2020] [Revised: 06/28/2021] [Accepted: 07/01/2021] [Indexed: 02/07/2023]
Abstract
Adelgids (Insecta: Hemiptera: Adelgidae) form a small group of insects but harbor a surprisingly diverse set of bacteriocyte-associated endosymbionts, which suggest multiple replacement and acquisition of symbionts over evolutionary time. Specific pairs of symbionts have been associated with adelgid lineages specialized on different secondary host conifers. Using a metagenomic approach, we investigated the symbiosis of the Adelges laricis/Adelges tardus species complex containing betaproteobacterial ("Candidatus Vallotia tarda") and gammaproteobacterial ("Candidatus Profftia tarda") symbionts. Genomic characteristics and metabolic pathway reconstructions revealed that Vallotia and Profftia are evolutionary young endosymbionts, which complement each other's role in essential amino acid production. Phylogenomic analyses and a high level of genomic synteny indicate an origin of the betaproteobacterial symbiont from endosymbionts of Rhizopus fungi. This evolutionary transition was accompanied with substantial loss of functions related to transcription regulation, secondary metabolite production, bacterial defense mechanisms, host infection, and manipulation. The transition from fungus to insect endosymbionts extends our current framework about evolutionary trajectories of host-associated microbes.
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Affiliation(s)
- Gitta Szabó
- Department of Microbiology and Ecosystem Science, Centre for Microbiology and Environmental Systems Science, University of Vienna, Vienna, Austria.
- Department of Internal Medicine and Oncology, Semmelweis University, Budapest, Hungary.
| | - Frederik Schulz
- Department of Microbiology and Ecosystem Science, Centre for Microbiology and Environmental Systems Science, University of Vienna, Vienna, Austria
- US Department of Energy (DOE) Joint Genome Institute, Berkeley, CA, USA
| | - Alejandro Manzano-Marín
- Department of Microbiology and Ecosystem Science, Centre for Microbiology and Environmental Systems Science, University of Vienna, Vienna, Austria
| | - Elena Rebecca Toenshoff
- Department of Microbiology and Ecosystem Science, Centre for Microbiology and Environmental Systems Science, University of Vienna, Vienna, Austria
- Institute of Molecular Biology and Biophysics, ETH Zurich, Zurich, Switzerland
| | - Matthias Horn
- Department of Microbiology and Ecosystem Science, Centre for Microbiology and Environmental Systems Science, University of Vienna, Vienna, Austria
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14
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Mounting, structure and autocleavage of a type VI secretion-associated Rhs polymorphic toxin. Nat Commun 2021; 12:6998. [PMID: 34853317 PMCID: PMC8636562 DOI: 10.1038/s41467-021-27388-0] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2021] [Accepted: 11/15/2021] [Indexed: 12/30/2022] Open
Abstract
Bacteria have evolved toxins to outcompete other bacteria or to hijack host cell pathways. One broad family of bacterial polymorphic toxins gathers multidomain proteins with a modular organization, comprising a C-terminal toxin domain fused to a N-terminal domain that adapts to the delivery apparatus. Polymorphic toxins include bacteriocins, contact-dependent growth inhibition systems, and specialized Hcp, VgrG, PAAR or Rhs Type VI secretion (T6SS) components. We recently described and characterized Tre23, a toxin domain fused to a T6SS-associated Rhs protein in Photorhabdus laumondii, Rhs1. Here, we show that Rhs1 forms a complex with the T6SS spike protein VgrG and the EagR chaperone. Using truncation derivatives and cross-linking mass spectrometry, we demonstrate that VgrG-EagR-Rhs1 complex formation requires the VgrG C-terminal β-helix and the Rhs1 N-terminal region. We then report the cryo-electron-microscopy structure of the Rhs1-EagR complex, demonstrating that the Rhs1 central region forms a β-barrel cage-like structure that encapsulates the C-terminal toxin domain, and provide evidence for processing of the Rhs1 protein through aspartyl autoproteolysis. We propose a model for Rhs1 loading on the T6SS, transport and delivery into the target cell.
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15
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Oral Toxicity of Pseudomonas protegens against Muscoid Flies. Toxins (Basel) 2021; 13:toxins13110772. [PMID: 34822556 PMCID: PMC8621253 DOI: 10.3390/toxins13110772] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2021] [Revised: 10/24/2021] [Accepted: 10/29/2021] [Indexed: 12/03/2022] Open
Abstract
The bioinsecticidal action of Pseudomonas protegens has so far been reported against some target insects, and the mode of action remains unclear. In this study, the pathogenicity potential of a recently isolated strain of this bacterial species against fly larvae of medical and veterinary interest was determined. Preliminary experiments were conducted to determine the biocidal action by ingestion against Musca domestica and Lucilia caesar larvae, which highlighted a concentration-dependent effect, with LC50 values of 3.6 and 2.5 × 108 CFU/mL, respectively. Bacterial septicaemia was observed in the body of insects assuming bacterial cells by ingestion. Such rapid bacterial reproduction in the hemolymph supports a toxin-mediated mechanism of action involving the intestinal barrier overcoming. In order to gain more information on the interaction with the host, the relative time-course expression of selected P. protegens genes associated with virulence and pathogenicity, was determined by qPCR at the gut level during the first infection stage. Among target genes, chitinase D was the most expressed, followed by pesticin and the fluorescent insecticidal toxin fitD. According to our observations and to the diversity of metabolites P. protegens produces, the pathogenic interaction this bacterium can establish with different targets appears to be complex and multifactorial.
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16
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Johnstone BA, Christie MP, Morton CJ, Parker MW. X-ray crystallography shines a light on pore-forming toxins. Methods Enzymol 2021; 649:1-46. [PMID: 33712183 DOI: 10.1016/bs.mie.2021.01.001] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023]
Abstract
A common form of cellular attack by pathogenic bacteria is to secrete pore-forming toxins (PFTs). Capable of forming transmembrane pores in various biological membranes, PFTs have also been identified in a diverse range of other organisms such as sea anemones, earthworms and even mushrooms and trees. The mechanism of pore formation by PFTs is associated with substantial conformational changes in going from the water-soluble to transmembrane states of the protein. The determination of the crystal structures for numerous PFTs has shed much light on our understanding of these proteins. Other than elucidating the atomic structural details of PFTs and the conformational changes that must occur for pore formation, crystal structures have revealed structural homology that has led to the discovery of new PFTs and new PFT families. Here we review some key crystallographic results together with complimentary approaches for studying PFTs. We discuss how these studies have impacted our understanding of PFT function and guided research into biotechnical applications.
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Affiliation(s)
- Bronte A Johnstone
- Department of Biochemistry and Molecular Biology, Bio21 Molecular Science and Biotechnology Institute, The University of Melbourne, Parkville, VIC, Australia
| | - Michelle P Christie
- Department of Biochemistry and Molecular Biology, Bio21 Molecular Science and Biotechnology Institute, The University of Melbourne, Parkville, VIC, Australia
| | - Craig J Morton
- Department of Biochemistry and Molecular Biology, Bio21 Molecular Science and Biotechnology Institute, The University of Melbourne, Parkville, VIC, Australia
| | - Michael W Parker
- Department of Biochemistry and Molecular Biology, Bio21 Molecular Science and Biotechnology Institute, The University of Melbourne, Parkville, VIC, Australia; St. Vincent's Institute of Medical Research, Fitzroy, VIC, Australia.
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17
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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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18
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Song N, Chen L, Ren X, Waterfield NR, Yang J, Yang G. N-Glycans and sulfated glycosaminoglycans contribute to the action of diverse Tc toxins on mammalian cells. PLoS Pathog 2021; 17:e1009244. [PMID: 33539469 PMCID: PMC7861375 DOI: 10.1371/journal.ppat.1009244] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/19/2020] [Accepted: 12/18/2020] [Indexed: 01/11/2023] Open
Abstract
Tc toxin is an exotoxin composed of three subunits named TcA, TcB and TcC. Structural analysis revealed that TcA can form homopentamer that mediates the cellular recognition and delivery processes, thus contributing to the host tropism of Tc toxin. N-glycans and heparan sulfates have been shown to act as receptors for several Tc toxins. Here, we performed two independent genome-wide CRISPR-Cas9 screens, and have validated glycans and sulfated glycosaminoglycans (sGAGs) as Tc toxin receptors also for previously uncharacterized Tc toxins. We found that TcdA1 form Photorhabdus luminescens W14 (TcdA1W14) can recognize N-glycans via the RBD-D domain, corroborating previous findings. Knockout of N-glycan processing enzymes specifically blocks the intoxication of TcdA1W14-assembled Tc toxin. On the other hand, our results showed that sGAG biosynthesis pathway is involved in the cell surface binding of TcdA2TT01 (TcdA2 from P. luminescens TT01). Competition assays and biolayer interferometry demonstrated that the sulfation group in sGAGs is required for the binding of TcdA2TT01. Finally, based on the conserved domains of representative TcA proteins, we have identified 1,189 putative TcAs from 1,039 bacterial genomes. These TcAs are categorized into five subfamilies. Each subfamily shows a good correlation with both genetic organization of the TcA protein(s) and taxonomic origin of the genomes, suggesting these subfamilies may utilize different mechanisms for cellular recognition. Taken together, our results support the previously described two different binding modalities of Tc toxins, leading to unique host targeting properties. We also present the bioinformatics data and receptor screening strategies for TcA proteins, provide new insights into understanding host specificity and biomedical applications of Tc toxins. The Toxin complexes, also referred to as Tc toxins, are a family of A5BC exotoxins widely distributed among Gram-negative and positive bacteria. First identified in Entomopathogenic bacteria as key virulence factors to combat insect hosts, putative Tc toxin loci are also encoded by a range of human pathogens such as Salmonella and Yersinia. Previous studies indicated that several Tc toxins can target invertebrate and vertebrate cells via binding with N-glycans and heparan sulfates. Here our genome-wide CRISPR-Cas9 screens validated that different Tc toxins utilized distinct receptors for the adhesion to their targets, which is determined by TcA homopentamer. For example, TcdA1 from Photorhabdus luminescens W14 (TcdA1W14) relies on N-glycan binding to exert its toxic effects, while sulfate groups of sulfated glycosaminoglycans are critical for the cell targeting of other TcAs such as TcdA2TT01 (TcdA2 from P. luminescens TT01). Consistent with the previously described different binding modalities of Tc toxins, our results confirm that the receptor selectivity of TcAs contribute to the cellular tropism of Tc toxins. Furthermore we has also identified 1,189 TcA homologues and categorized them into five subfamilies. Each TcA subfamily shows a good correlation with the taxonomic origin of the genomes, suggesting these subfamilies are linked to diverse host tropisms via different binding modalities. Together, our findings provide mechanistic insights into understanding host specificity of distinct Tc toxins and the development of therapeutics for Tc toxin-related infections, as well as the adaptation of Tc-injectisomes as potential biotechnology tools and pest-control weapons.
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Affiliation(s)
- Nan Song
- Beijing Institute of Tropical Medicine, Beijing Friendship Hospital, Capital Medical University, 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
| | - Xingmei Ren
- Beijing Institute of Tropical Medicine, Beijing Friendship Hospital, Capital Medical University, 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
| | - Guowei Yang
- Beijing Institute of Tropical Medicine, Beijing Friendship Hospital, Capital Medical University, Beijing, China
- Emergency and Critical Care Center, Beijing Friendship Hospital, Capital Medical University, Beijing, China
- * E-mail:
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19
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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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20
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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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21
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Glycoside hydrolase family 18 chitinases: The known and the unknown. Biotechnol Adv 2020; 43:107553. [DOI: 10.1016/j.biotechadv.2020.107553] [Citation(s) in RCA: 40] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/08/2020] [Revised: 03/09/2020] [Accepted: 04/20/2020] [Indexed: 12/13/2022]
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22
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Roderer D, Bröcker F, Sitsel O, Kaplonek P, Leidreiter F, Seeberger PH, Raunser S. Glycan-dependent cell adhesion mechanism of Tc toxins. Nat Commun 2020; 11:2694. [PMID: 32483155 PMCID: PMC7264150 DOI: 10.1038/s41467-020-16536-7] [Citation(s) in RCA: 17] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/10/2019] [Accepted: 05/11/2020] [Indexed: 01/19/2023] Open
Abstract
Toxin complex (Tc) toxins are virulence factors of pathogenic bacteria. Tcs are composed of three subunits: TcA, TcB and TcC. TcA facilitates receptor-toxin interaction and membrane permeation, TcB and TcC form a toxin-encapsulating cocoon. While the mechanisms of holotoxin assembly and pore formation have been described, little is known about receptor binding of TcAs. Here, we identify heparins/heparan sulfates and Lewis antigens as receptors for different TcAs from insect and human pathogens. Glycan array screening reveals that all tested TcAs bind negatively charged heparins. Cryo-EM structures of Morganella morganii TcdA4 and Xenorhabdus nematophila XptA1 reveal that heparins/heparan sulfates unexpectedly bind to different regions of the shell domain, including receptor-binding domains. In addition, Photorhabdus luminescens TcdA1 binds to Lewis antigens with micromolar affinity. Here, the glycan interacts with the receptor-binding domain D of the toxin. Our results suggest a glycan dependent association mechanism of Tc toxins on the host cell surface.
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Affiliation(s)
- Daniel Roderer
- Department of Structural Biochemistry, Max Planck Institute of Molecular Physiology, 44227, Dortmund, Germany
| | - Felix Bröcker
- Department of Biomolecular Systems, Max Planck Institute of Colloids and Interfaces, 14476, Potsdam, Germany
- Vaxxilon Deutschland GmbH, 12489, Berlin, Germany
| | - Oleg Sitsel
- Department of Structural Biochemistry, Max Planck Institute of Molecular Physiology, 44227, Dortmund, Germany
| | - Paulina Kaplonek
- Department of Biomolecular Systems, Max Planck Institute of Colloids and Interfaces, 14476, Potsdam, Germany
- Ragon Institute of MGH, MIT and Harvard, Cambridge, MA, 02139, USA
| | - Franziska Leidreiter
- Department of Structural Biochemistry, Max Planck Institute of Molecular Physiology, 44227, Dortmund, Germany
- Department of Biomolecular Mechanisms, Max Planck Institute for Medical Research, 69120, Heidelberg, Germany
| | - Peter H Seeberger
- Department of Biomolecular Systems, Max Planck Institute of Colloids and Interfaces, 14476, Potsdam, Germany
| | - Stefan Raunser
- Department of Structural Biochemistry, Max Planck Institute of Molecular Physiology, 44227, Dortmund, Germany.
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23
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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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24
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Leidreiter F, Roderer D, Meusch D, Gatsogiannis C, Benz R, Raunser S. Common architecture of Tc toxins from human and insect pathogenic bacteria. SCIENCE ADVANCES 2019; 5:eaax6497. [PMID: 31663026 PMCID: PMC6795518 DOI: 10.1126/sciadv.aax6497] [Citation(s) in RCA: 21] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 04/10/2019] [Accepted: 09/18/2019] [Indexed: 06/10/2023]
Abstract
Tc toxins use a syringe-like mechanism to penetrate the membrane and translocate toxic enzymes into the host cytosol. They are composed of three components: TcA, TcB, and TcC. Low-resolution structures of TcAs from different bacteria suggest a considerable difference in their architecture and possibly in their mechanism of action. Here, we present high-resolution structures of five TcAs from insect and human pathogens, which show a similar overall composition and domain organization. Essential structural features, including a trefoil protein knot, are present in all TcAs, suggesting a common mechanism of action. All TcAs form functional pores and can be combined with TcB-TcC subunits from other species to form active chimeric holotoxins. We identified a conserved ionic pair that stabilizes the shell, likely operating as a strong latch that only springs open after destabilization of other regions. Our results provide new insights into the architecture and mechanism of the Tc toxin family.
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Affiliation(s)
- F. Leidreiter
- Department of Structural Biochemistry, Max Planck Institute of Molecular Physiology, Otto-Hahn-Str. 11, 44227 Dortmund, Germany
| | - D. Roderer
- Department of Structural Biochemistry, Max Planck Institute of Molecular Physiology, Otto-Hahn-Str. 11, 44227 Dortmund, Germany
| | - D. Meusch
- Department of Structural Biochemistry, Max Planck Institute of Molecular Physiology, Otto-Hahn-Str. 11, 44227 Dortmund, Germany
| | - C. Gatsogiannis
- Department of Structural Biochemistry, Max Planck Institute of Molecular Physiology, Otto-Hahn-Str. 11, 44227 Dortmund, Germany
| | - R. Benz
- Department of Life Sciences and Chemistry, Jacobs University Bremen, Campusring 1, 28759 Bremen, Germany
| | - S. Raunser
- Department of Structural Biochemistry, Max Planck Institute of Molecular Physiology, Otto-Hahn-Str. 11, 44227 Dortmund, Germany
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25
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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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26
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Araç D, Li J. Teneurin Structure: Splice Variants of a Bacterial Toxin Homolog Specifies Synaptic Connections. Front Neurosci 2019; 13:838. [PMID: 31440135 PMCID: PMC6693077 DOI: 10.3389/fnins.2019.00838] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/24/2019] [Accepted: 07/26/2019] [Indexed: 11/20/2022] Open
Abstract
Teneurins are a conserved family of cell-surface adhesion molecules that mediate cellular communication, and play key roles in embryonic and neural development. Their mechanisms of action remained unclear due in part to their unknown structures. In recent years, the structures of teneurins have been reported at atomic resolutions and revealed a clear homology to bacterial Tc toxins with no similarity to other eukaryotic proteins. Another surprising observation was that alternatively spliced variants of teneurins interact with distinct ligands, and thus specify excitatory vs. inhibitory synapses. In this review, we discuss teneurin structures that together with structure-guided biochemical and functional analyses, provide insights for the mechanisms of trans-cellular communication at the synapse and other cell-cell contact sites.
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Affiliation(s)
- Demet Araç
- Department of Biochemistry & Molecular Biology, The University of Chicago, Chicago, IL, United States.,Grossman Institute for Neuroscience, Quantitative Biology and Human Behavior, The University of Chicago, Chicago, IL, United States
| | - Jingxian Li
- Department of Biochemistry & Molecular Biology, The University of Chicago, Chicago, IL, United States.,Grossman Institute for Neuroscience, Quantitative Biology and Human Behavior, The University of Chicago, Chicago, IL, United States
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27
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Liu J, NanGong Z, Zhang J, Song P, Tang Y, Gao Y, Wang Q. Expression and characterization of two chitinases with synergistic effect and antifungal activity from Xenorhabdus nematophila. World J Microbiol Biotechnol 2019; 35:106. [PMID: 31267229 DOI: 10.1007/s11274-019-2670-5] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/22/2019] [Accepted: 06/05/2019] [Indexed: 12/18/2022]
Abstract
Xenorhabdus nematophila HB310 secreted the insecticidal protein toxin complex. Two chitinase genes, chi60 and chi70, were found in X. nematophila toxin complex locus. In order to clarify the function of two chitinases, chi60 and chi70 genes were cloned and expressed in Escherichia coli Transetta (DE3). As a result, we found that the Chi60 and Chi70 belonged to glycoside hydrolases (GH) family 18 with a molecular mass of 65 kDa and 78 kDa, respectively. When colloidal chitin was treated as the substrate, Chi60 and Chi70 were proved to have the highest enzymatic activity at pH 6.0 and 50 °C. Chi60 and Chi70 had obvious growth inhibition effect against the second larvae of Helicoverpa armigera with growth inhibiting rate of 81.99% and 90.51%. Chi70 had synergistic effect with the insecticidal toxicity of Bt Cry 1Ac, but the Chi60 had no synergistic effect with Bt Cry 1Ac. Chi60 and Chi70 showed antifungal activity against Alternaria brassicicola, Verticillium dahliae and Coniothyrium diplodiella. The results increased our understanding of the chitinases produced by X. nematophila and laid a foundation for further studies on the mechanism of the chitinases.
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Affiliation(s)
- Jia Liu
- College of Plant Protection, Hebei Agricultural University, Baoding, 071001, Hebei, China
| | - Ziyan NanGong
- College of Plant Protection, Hebei Agricultural University, Baoding, 071001, Hebei, China
| | - Jie Zhang
- Luanping State-Owned Forestry Farm Management of Chengde City, Chengde, 068250, China
| | - Ping Song
- College of Plant Protection, Hebei Agricultural University, Baoding, 071001, Hebei, China
| | - Yin Tang
- College of Plant Protection, Hebei Agricultural University, Baoding, 071001, Hebei, China
| | - Yue Gao
- College of Plant Protection, Hebei Agricultural University, Baoding, 071001, Hebei, China
| | - Qinying Wang
- College of Plant Protection, Hebei Agricultural University, Baoding, 071001, Hebei, China.
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28
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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] [Key Words] [MESH Headings] [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.
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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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29
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Araç D, Li J. Teneurins and latrophilins: two giants meet at the synapse. Curr Opin Struct Biol 2019; 54:141-151. [PMID: 30952063 DOI: 10.1016/j.sbi.2019.01.028] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/07/2018] [Revised: 01/10/2019] [Accepted: 01/22/2019] [Indexed: 12/19/2022]
Abstract
Teneurins and latrophilins are both conserved families of cell adhesion proteins that mediate cellular communication and play critical roles in embryonic and neural development. However, their mechanisms of action remain poorly understood. In the past several years, three-dimensional structures of teneurins and latrophilins have been reported at atomic resolutions and revealed distinct protein folds and unique structural features. In this review, we discuss these structures which, together with structure-guided biochemical and functional analyses, provide hints for the mechanisms of trans-cellular communication at the synapse and other cell-cell contact sites.
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Affiliation(s)
- Demet Araç
- Department of Biochemistry and Molecular Biology, The University of Chicago, Chicago, IL 60637, USA; Grossman Institute for Neuroscience, Quantitative Biology and Human Behavior, The University of Chicago, IL 60637, USA.
| | - Jingxian Li
- Department of Biochemistry and Molecular Biology, The University of Chicago, Chicago, IL 60637, USA; Grossman Institute for Neuroscience, Quantitative Biology and Human Behavior, The University of Chicago, IL 60637, USA
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30
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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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31
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Li J, Shalev-Benami M, Sando R, Jiang X, Kibrom A, Wang J, Leon K, Katanski C, Nazarko O, Lu YC, Südhof TC, Skiniotis G, Araç D. Structural Basis for Teneurin Function in Circuit-Wiring: A Toxin Motif at the Synapse. Cell 2019; 173:735-748.e15. [PMID: 29677516 DOI: 10.1016/j.cell.2018.03.036] [Citation(s) in RCA: 89] [Impact Index Per Article: 17.8] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/07/2017] [Revised: 02/14/2018] [Accepted: 03/15/2018] [Indexed: 11/28/2022]
Abstract
Teneurins (TENs) are cell-surface adhesion proteins with critical roles in tissue development and axon guidance. Here, we report the 3.1-Å cryoelectron microscopy structure of the human TEN2 extracellular region (ECR), revealing a striking similarity to bacterial Tc-toxins. The ECR includes a large β barrel that partially encapsulates a C-terminal domain, which emerges to the solvent through an opening in the mid-barrel region. An immunoglobulin (Ig)-like domain seals the bottom of the barrel while a β propeller is attached in a perpendicular orientation. We further show that an alternatively spliced region within the β propeller acts as a switch to regulate trans-cellular adhesion of TEN2 to latrophilin (LPHN), a transmembrane receptor known to mediate critical functions in the central nervous system. One splice variant activates trans-cellular signaling in a LPHN-dependent manner, whereas the other induces inhibitory postsynaptic differentiation. These results highlight the unusual structural organization of TENs giving rise to their multifarious functions.
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Affiliation(s)
- Jingxian Li
- Department of Biochemistry and Molecular Biology, The University of Chicago, Chicago, IL 60637, USA; Grossman Institute for Neuroscience, Quantitative Biology and Human Behavior, The University of Chicago, Chicago, IL 60637, USA
| | - Moran Shalev-Benami
- Department of Molecular and Cellular Physiology, Stanford University, Stanford, CA 94305, USA; Department of Structural Biology, Stanford University, Stanford, CA 94305, USA
| | - Richard Sando
- Department of Molecular and Cellular Physiology, Stanford University, Stanford, CA 94305, USA; Howard Hughes Medical Institute, Stanford University, Stanford, CA 94305, USA
| | - Xian Jiang
- Department of Molecular and Cellular Physiology, Stanford University, Stanford, CA 94305, USA; Howard Hughes Medical Institute, Stanford University, Stanford, CA 94305, USA
| | - Amanuel Kibrom
- Department of Biochemistry and Molecular Biology, The University of Chicago, Chicago, IL 60637, USA; Grossman Institute for Neuroscience, Quantitative Biology and Human Behavior, The University of Chicago, Chicago, IL 60637, USA
| | - Jie Wang
- Department of Molecular and Cellular Physiology, Stanford University, Stanford, CA 94305, USA; Howard Hughes Medical Institute, Stanford University, Stanford, CA 94305, USA
| | - Katherine Leon
- Department of Biochemistry and Molecular Biology, The University of Chicago, Chicago, IL 60637, USA; Grossman Institute for Neuroscience, Quantitative Biology and Human Behavior, The University of Chicago, Chicago, IL 60637, USA
| | - Christopher Katanski
- Department of Biochemistry and Molecular Biology, The University of Chicago, Chicago, IL 60637, USA; Grossman Institute for Neuroscience, Quantitative Biology and Human Behavior, The University of Chicago, Chicago, IL 60637, USA
| | - Olha Nazarko
- Department of Biochemistry and Molecular Biology, The University of Chicago, Chicago, IL 60637, USA; Grossman Institute for Neuroscience, Quantitative Biology and Human Behavior, The University of Chicago, Chicago, IL 60637, USA
| | - Yue C Lu
- Department of Biochemistry and Molecular Biology, The University of Chicago, Chicago, IL 60637, USA; Grossman Institute for Neuroscience, Quantitative Biology and Human Behavior, The University of Chicago, Chicago, IL 60637, USA
| | - Thomas C Südhof
- Department of Molecular and Cellular Physiology, Stanford University, Stanford, CA 94305, USA; Howard Hughes Medical Institute, Stanford University, Stanford, CA 94305, USA.
| | - Georgios Skiniotis
- Department of Molecular and Cellular Physiology, Stanford University, Stanford, CA 94305, USA; Department of Structural Biology, Stanford University, Stanford, CA 94305, USA.
| | - Demet Araç
- Department of Biochemistry and Molecular Biology, The University of Chicago, Chicago, IL 60637, USA; Grossman Institute for Neuroscience, Quantitative Biology and Human Behavior, The University of Chicago, Chicago, IL 60637, USA.
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32
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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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33
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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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34
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Ost GS, Ng'ang'a PN, Lang AE, Aktories K. Photorhabdus luminescens
Tc toxin is inhibited by the protease inhibitor MG132 and activated by protease cleavage resulting in increased binding to target cells. Cell Microbiol 2018; 21:e12978. [DOI: 10.1111/cmi.12978] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/17/2018] [Revised: 10/19/2018] [Accepted: 11/04/2018] [Indexed: 12/24/2022]
Affiliation(s)
- Gerhard Stefan Ost
- Institute for Experimental and Clinical Pharmacology and Toxicology, Faculty of Medicine; University of Freiburg; Freiburg Germany
- Faculty of Biology; University of Freiburg; Freiburg Germany
| | - Peter Njenga Ng'ang'a
- Institute for Experimental and Clinical Pharmacology and Toxicology, Faculty of Medicine; University of Freiburg; Freiburg Germany
- Faculty of Biology; University of Freiburg; Freiburg Germany
- Spemann Graduate School of Biology and Medicine (SGBM); University of Freiburg; Freiburg Germany
| | - Alexander E. Lang
- Institute for Experimental and Clinical Pharmacology and Toxicology, Faculty of Medicine; University of Freiburg; Freiburg Germany
| | - Klaus Aktories
- Institute for Experimental and Clinical Pharmacology and Toxicology, Faculty of Medicine; University of Freiburg; Freiburg Germany
- Centre for Biological Signalling Studies (BIOSS); University of Freiburg; Freiburg Germany
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35
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Abstract
Microbial biopesticides include several microorganisms like bacteria, fungi, baculoviruses, and nematode-associated bacteria acting against invertebrate pests in agro-ecosystems. The biopesticide sector is experiencing a significant growth and many discoveries are being developed into new biopesticidal products that are fueling a growing global market offer. Following a few decades of successful use of the entomopathogenic bacterium Bacillus thuringiensis and a few other microbial species, recent academic and industrial efforts have led to the discovery of new microbial species and strains, and of their specific toxins and virulence factors. Many of these have, therefore, been developed into commercial products. Bacterial entomopathogens include several Bacillaceae, Serratia, Pseudomonas, Yersinia, Burkholderia, Chromobacterium, Streptomyces, and Saccharopolyspora species, while fungi comprise different strains of Beauveria bassiana, B. brongniartii, Metarhizium anisopliae, Verticillium, Lecanicillium, Hirsutella, Paecilomyces, and Isaria species. Baculoviruses are species-specific and refer to niche products active against chewing insects, especially Lepidopteran caterpillars. Entomopathogenic nematodes (EPNs) mainly include species in the genera Heterorhabditis and Steinernema associated with mutualistic symbiotic bacteria belonging to the genera Photorhabdus and Xenorhabdus. An updated representation of the current knowledge on microbial biopesticides and of the availability of active substances that can be used in integrated pest management programs in agro-ecosystems is reported here.
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36
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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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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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Gatsogiannis C, Merino F, Prumbaum D, Roderer D, Leidreiter F, Meusch D, Raunser S. Membrane insertion of a Tc toxin in near-atomic detail. Nat Struct Mol Biol 2016; 23:884-890. [PMID: 27571177 DOI: 10.1038/nsmb.3281] [Citation(s) in RCA: 65] [Impact Index Per Article: 8.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/06/2016] [Accepted: 07/26/2016] [Indexed: 12/22/2022]
Abstract
Tc toxins from pathogenic bacteria use a special syringe-like mechanism to perforate the host cell membrane and inject a deadly enzyme into the host cytosol. The molecular mechanism of this unusual injection system is poorly understood. Using electron cryomicroscopy, we determined the structure of TcdA1 from Photorhabdus luminescens embedded in lipid nanodiscs. In our structure, compared with the previous structure of TcdA1 in the prepore state, the transmembrane helices rearrange in the membrane and open the initially closed pore. However, the helices do not span the complete membrane; instead, the loops connecting the helices form the rim of the funnel. Lipid head groups reach into the space between the loops and consequently stabilize the pore conformation. The linker domain is folded and packed into a pocket formed by the other domains of the toxin, thereby considerably contributing to stabilization of the pore state.
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Affiliation(s)
- Christos Gatsogiannis
- Department of Structural Biochemistry, Max Planck Institute of Molecular Physiology, Dortmund, Germany
| | - Felipe Merino
- Department of Structural Biochemistry, Max Planck Institute of Molecular Physiology, Dortmund, Germany
| | - Daniel Prumbaum
- Department of Structural Biochemistry, Max Planck Institute of Molecular Physiology, Dortmund, Germany
| | - Daniel Roderer
- Department of Structural Biochemistry, Max Planck Institute of Molecular Physiology, Dortmund, Germany
| | - Franziska Leidreiter
- Department of Structural Biochemistry, Max Planck Institute of Molecular Physiology, Dortmund, Germany
| | - Dominic Meusch
- 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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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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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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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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Tang KFJ, Lightner DV. Homologues of insecticidal toxin complex genes within a genomic island in the marine bacterium Vibrio parahaemolyticus. FEMS Microbiol Lett 2015; 361:34-42. [PMID: 25272969 DOI: 10.1111/1574-6968.12609] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/29/2014] [Revised: 09/21/2014] [Accepted: 09/24/2014] [Indexed: 01/13/2023] Open
Abstract
Three insecticidal toxin complex (tc)-like genes were identified in Vibrio parahaemolyticus 13-028/A3, which can cause acute hepatopancreatic necrosis disease in penaeid shrimp. The three genes are a tcdA-like gene (7710 bp), predicted to code for a 284-kDa protein; a tcdB-like gene (4272 bp), predicted to code for a 158-kDa protein; and a tccC3-like gene (2916 bp), predicted to encode a 107-kDa protein. All three predicted proteins contain conserved domains that are characteristic of their respective Tc proteins. By RT-PCR, all three tc-like genes were found to be expressed in this bacterium. Through genome walking and the use of PCR to join contigs surrounding these three genes, a genomic island (87 712 bp, named tc-GIvp) was found on chromosome II localized next to the tRNA Gly. The GC content of this island, which is not found in other Vibrio species, is 40%. The tc-GIvp is characterized to have 60 ORFs encoding regulatory or virulence factors. These include a type 6 secretion protein VgrG, EAL domain-containing proteins, fimbriae subunits and assembly proteins, invasin-like proteins, peptidoglycan-binding proteins, and Tc proteins. The tc-GIvp also contains 21 transposase genes, suggesting that it was acquired through horizontal transfer from other organisms.
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Affiliation(s)
- Kathy F J Tang
- School of Animal and Comparative Biomedical Sciences, University of Arizona, Tucson, AZ, USA
| | - Donald V Lightner
- School of Animal and Comparative Biomedical Sciences, University of Arizona, Tucson, AZ, USA
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Starke M, Fuchs TM. YmoA negatively controls the expression of insecticidal genes in Yersinia enterocolitica. Mol Microbiol 2014; 92:287-301. [PMID: 24548183 DOI: 10.1111/mmi.12554] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 02/13/2014] [Indexed: 11/28/2022]
Abstract
Yersinia enterocolitica is toxic towards invertebrates due to the presence of the toxin complex (tc) genes that are activated by the thermolabile regulator TcaR2. In the search for further regulatory factors involved in insecticidal gene expression, the modulator of yersinial virulence, YmoA, was identified to silence all tc genes of the Y. enterocolitica strain W22703 (biovar 2, serovar O:9). Using promoter fusions with the luciferase reporter, we found that the deletion of ymoA results in elevated transcription of tcaR1, tcaR2, tcaA, tcaB, tcaC, tccC1 and tccC2 at both 15 °C and 37 °C. Complementation by episomal ymoA significantly reduced tc gene expression, thus validating the inhibitory activity of YmoA on the production of insecticidal proteins. YmoA contributes to the binding properties of H-NS to the tc promoters by forming a complex with this nucleoid-associated protein, and this complex not only binds to the upstream regions of all tc genes, but also to intragenic sites of tcaA and tcaB that play an important role in controlling the expression of both genes. At low temperature, the intracellular amount of thermostable YmoA is not reduced, but the repressor is less functional. These data point to H-NS/YmoA as an antagonist of the inducer TcaR2.
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Affiliation(s)
- Mandy Starke
- Lehrstuhl für Mikrobielle Ökologie, Department für biowissenschaftliche Grundlagen, Wissenschaftszentrum Weihenstephan, Technische Universität München, Weihenstephaner Berg 3, 85354, Freising, Germany
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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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Mechanism of Tc toxin action revealed in molecular detail. Nature 2014; 508:61-5. [DOI: 10.1038/nature13015] [Citation(s) in RCA: 121] [Impact Index Per Article: 12.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/10/2013] [Accepted: 01/10/2014] [Indexed: 12/20/2022]
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TcdA1 of Photorhabdus luminescens: electrophysiological analysis of pore formation and effector binding. Biophys J 2014; 105:376-84. [PMID: 23870259 DOI: 10.1016/j.bpj.2013.06.003] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/28/2013] [Revised: 06/03/2013] [Accepted: 06/03/2013] [Indexed: 11/23/2022] Open
Abstract
Tc toxins are widely distributed among different gram-negative and gram-positive bacteria, where they act as pathogenicity factors. The toxins are composed of different components that form oligomers for biological activity. Lipid bilayer experiments were performed with the TcdA1 component of the Tc toxin from Photorhabdus luminescens, which preferentially kills insects by actin polymerization. TcdA1 was able to increase the specific conductance of artificial lipid bilayer membranes by the formation of ion-permeable channels. The channels had on average a single-channel conductance of 125 pS in 150 mM KCl and were found to be cation selective. The single-channel conductance of the TcdA1-channels was only moderately dependent on the bulk aqueous KCl concentration, which indicated point-charge effects on the channel properties. Experiments to study the voltage dependence of the TcdA1 channel demonstrated that it is reconstituted in a fully oriented way when it is added to only one side of the lipid bilayer membrane. A combination of biologically active components (TccC3) and a possible chaperone (TcdB2) blocked the TcdA1-mediated conductance efficiently in a dose-dependent manner when they were added to the cis side of the membrane. The half-saturation constant for binding of TcdB2-TccC3 to TcdA1 is in the low nanomolar range.
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Aktories K, Schmidt G, Lang AE. Photorhabdus luminescens toxins TccC3 and TccC5: insecticidal ADP-ribosyltransferases that modify threonine and glutamine. Curr Top Microbiol Immunol 2014; 384:53-67. [PMID: 24908144 DOI: 10.1007/82_2014_382] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/04/2023]
Abstract
The ADP-ribosyltransferases TccC3 and TccC5 are the biologically active TcC components of the tripartite Photorhabdus luminescens Tc toxin, which consist of TcA, TcB, and TcC components. TcA is the binding and membrane translocation component. TcB is a functional linker between TcC and TcA and also involved in the translocation of the toxin. While TccC3 ADP-ribosylates actin at threonine 148, TccC5 modifies Rho proteins at glutamine 61/63. Both modifications result in major alteration of the actin cytoskeleton. Here we discuss structure and function of the Tc toxin and compare its ADP-ribosyltransferase activities with other types of actin and Rho modifying toxins.
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Affiliation(s)
- Klaus Aktories
- Institut für Experimentelle und Klinische Pharmakologie und Toxikologie, Albert-Ludwigs-Universität Freiburg, Albertstr. 25, 79104, Freiburg, Germany,
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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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