1
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Dokuz S, Tasdurmazli S, Acar T, Duran GN, Ozdemir C, Ozbey U, Ozbil M, Karadayi S, Bayrak OF, Derman S, Chen JYS, Ozbek T. Evaluation of Bacteriophage ϕ11 host recognition protein and its host-binding peptides for diagnosing/targeting Staphylococcus aureus infections. Int J Antimicrob Agents 2024; 64:107230. [PMID: 38824973 DOI: 10.1016/j.ijantimicag.2024.107230] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/28/2024] [Revised: 05/14/2024] [Accepted: 05/28/2024] [Indexed: 06/04/2024]
Abstract
BACKGROUND Evaluating the potential of using both synthetic and biological products as targeting agents for the diagnosis, imaging, and treatment of infections due to particularly antibiotic-resistant pathogens is important for controlling infections. This study examined the interaction between Gp45, a receptor-binding protein of the ϕ11 lysogenic phage, and its host Staphylococcus aureus (S. aureus), a common cause of nosocomial infections. METHODS Using molecular dynamics and docking simulations, this study identified the peptides that bind to S. aureus wall teichoic acids via Gp45. It compared the binding affinity of Gp45 and the two highest-scoring peptide sequences (P1 and P3) and their scrambled forms using microscopy, spectroscopy, and ELISA. RESULTS It was found that rGp45 (recombinant Gp45) and chemically synthesised P1 had a higher binding affinity for S. aureus compared with all other peptides, except for Escherichia coli. Furthermore, rGp45 had a capture efficiency of > 86%; P1 had a capture efficiency of > 64%. CONCLUSION These findings suggest that receptor-binding proteins such as rGp45, which provide a critical initiation of the phage life cycle for host adsorption, might play an important role in the diagnosis, imaging, and targeting of bacterial infections. Studying such proteins could accordingly enable the development of effective strategies for controlling infections.
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Affiliation(s)
- Senanur Dokuz
- Department of Molecular Biology and Genetics, Faculty of Arts and Sciences, Yildiz Technical University, Istanbul, Turkey
| | - Semra Tasdurmazli
- Department of Molecular Biology and Genetics, Faculty of Arts and Sciences, Yildiz Technical University, Istanbul, Turkey
| | - Tayfun Acar
- Department of Bioengineering, Faculty of Chemical and Metallurgical Engineering, Yildiz Technical University, Istanbul, Turkey
| | - Gizem Nur Duran
- Institute of Biotechnology, Gebze Technical University, Kocaeli, Turkey
| | - Cilem Ozdemir
- Department of Medical Biology, Health Sciences Institution, Mugla Sitki Kocman University, Mugla, Turkey
| | - Utku Ozbey
- Department of Medical Genetics, School of Medicine, Yeditepe University, Istanbul, Turkey
| | - Mehmet Ozbil
- Institute of Biotechnology, Gebze Technical University, Kocaeli, Turkey
| | - Sukriye Karadayi
- Department of Medical Laboratory Techniques, Vocational School of Health Services, Altınbas University, Istanbul, Turkey
| | - Omer Faruk Bayrak
- Department of Medical Genetics, School of Medicine, Yeditepe University, Istanbul, Turkey
| | - Serap Derman
- Department of Bioengineering, Faculty of Chemical and Metallurgical Engineering, Yildiz Technical University, Istanbul, Turkey
| | - John Yu-Shen Chen
- Department of Microbiology and Immunology, Yong Loo Lin School of Medicine, National University of Singapore, Singapore
| | - Tulin Ozbek
- Department of Molecular Biology and Genetics, Faculty of Arts and Sciences, Yildiz Technical University, Istanbul, Turkey.
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2
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Fecht S, Paracuellos P, Subramoni S, Tan CAZ, Ilangovan A, Costa TRD, Filloux A. Functionality of chimeric TssA proteins in the type VI secretion system reveals sheath docking specificity within their N-terminal domains. Nat Commun 2024; 15:4283. [PMID: 38769318 PMCID: PMC11106082 DOI: 10.1038/s41467-024-48487-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/19/2023] [Accepted: 05/01/2024] [Indexed: 05/22/2024] Open
Abstract
The genome of Pseudomonas aeruginosa encodes three type VI secretion systems, each comprising a dozen distinct proteins, which deliver toxins upon T6SS sheath contraction. The least conserved T6SS component, TssA, has variations in size which influence domain organisation and structure. Here we show that the TssA Nt1 domain interacts directly with the sheath in a specific manner, while the C-terminus is essential for oligomerisation. We built chimeric TssA proteins by swapping C-termini and showed that these can be functional even when made of domains from different TssA sub-groups. Functional specificity requires the Nt1 domain, while the origin of the C-terminal domain is more permissive for T6SS function. We identify two regions in short TssA proteins, loop and hairpin, that contribute to sheath binding. We propose a docking mechanism of TssA proteins with the sheath, and a model for how sheath assembly is coordinated by TssA proteins from this position.
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Affiliation(s)
- Selina Fecht
- CBRB Centre for Bacterial Resistance Biology, Department of Life Sciences, Imperial College London, London, SW7 2AZ, UK
| | - Patricia Paracuellos
- CBRB Centre for Bacterial Resistance Biology, Department of Life Sciences, Imperial College London, London, SW7 2AZ, UK
| | - Sujatha Subramoni
- Singapore Centre for Environmental Life Sciences Engineering, Nanyang Technological University, Singapore, 637551, Singapore
| | - Casandra Ai Zhu Tan
- Singapore Centre for Environmental Life Sciences Engineering, Nanyang Technological University, Singapore, 637551, Singapore
| | - Aravindan Ilangovan
- School of Biological and Behavioural Sciences, Queen Mary University of London, London, E1 4NS, UK
| | - Tiago R D Costa
- CBRB Centre for Bacterial Resistance Biology, Department of Life Sciences, Imperial College London, London, SW7 2AZ, UK
| | - Alain Filloux
- CBRB Centre for Bacterial Resistance Biology, Department of Life Sciences, Imperial College London, London, SW7 2AZ, UK.
- Singapore Centre for Environmental Life Sciences Engineering, Nanyang Technological University, Singapore, 637551, Singapore.
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3
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Cingolani G, Iglesias S, Hou CF, Lemire S, Soriaga A, Kyme P. Cryo-EM analysis of Pseudomonas phage Pa193 structural components. RESEARCH SQUARE 2024:rs.3.rs-4189479. [PMID: 38659960 PMCID: PMC11042391 DOI: 10.21203/rs.3.rs-4189479/v1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 04/26/2024]
Abstract
The World Health Organization has designated Pseudomonas aeruginosa as a critical pathogen for the development of new antimicrobials. Bacterial viruses, or bacteriophages, have been used in various clinical settings, commonly called phage therapy, to address this growing public health crisis. Here, we describe a high-resolution structural atlas of a therapeutic, contractile-tailed Pseudomonas phage, Pa193. We used bioinformatics, proteomics, and cryogenic electron microscopy single particle analysis to identify, annotate, and build atomic models for 21 distinct structural polypeptide chains forming the icosahedral capsid, neck, contractile tail, and baseplate. We identified a putative scaffolding protein stabilizing the interior of the capsid 5-fold vertex. We also visualized a large portion of Pa193 ~ 500 Å long tail fibers and resolved the interface between the baseplate and tail fibers. The work presented here provides a framework to support a better understanding of phages as biomedicines for phage therapy and inform engineering opportunities.
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4
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Cai X, He Y, Yu I, Imani A, Scholl D, Miller JF, Zhou ZH. Atomic structures of a bacteriocin targeting Gram-positive bacteria. RESEARCH SQUARE 2024:rs.3.rs-4007122. [PMID: 38586031 PMCID: PMC10996793 DOI: 10.21203/rs.3.rs-4007122/v1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 04/09/2024]
Abstract
Due to envelope differences between Gram-positive and Gram-negative bacteria1, engineering precision bactericidal contractile nanomachines2 requires atomic-level understanding of their structures; however, only those killing a Gram-negative bacterium are currently known3,4. Here, we report the atomic structures of an engineered diffocin, a contractile syringe-like molecular machine that kills the Gram-positive bacterium Clostridioides difficile. Captured in one pre-contraction and two post-contraction states, each structure fashions six proteins in the bacteria-targeting baseplate, two proteins in the energy-storing trunk, and a collar protein linking the sheath with the membrane-penetrating tube. Compared to contractile machines targeting Gram-negative bacteria, major differences reside in the baseplate and contraction magnitude, consistent with differences between their targeted envelopes. The multifunctional hub-hydrolase protein connects the tube and baseplate and is positioned to degrade peptidoglycan during penetration. The full-length tape measure protein forms a coiled-coil helix bundle homotrimer spanning the entire length of the diffocin. Our study offers mechanical insights and principles for designing potent protein-based precision antibiotics.
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Affiliation(s)
- Xiaoying Cai
- Department of Microbiology, Immunology and Molecular Genetics, University of California, Los Angeles (UCLA), Los Angeles, CA, USA
- The California NanoSystems Institute (CNSI), University of California, Los Angeles (UCLA), Los Angeles, CA, USA
| | - Yao He
- Department of Microbiology, Immunology and Molecular Genetics, University of California, Los Angeles (UCLA), Los Angeles, CA, USA
- The California NanoSystems Institute (CNSI), University of California, Los Angeles (UCLA), Los Angeles, CA, USA
| | - Iris Yu
- Department of Microbiology, Immunology and Molecular Genetics, University of California, Los Angeles (UCLA), Los Angeles, CA, USA
- The California NanoSystems Institute (CNSI), University of California, Los Angeles (UCLA), Los Angeles, CA, USA
| | - Anthony Imani
- Department of Microbiology, Immunology and Molecular Genetics, University of California, Los Angeles (UCLA), Los Angeles, CA, USA
- The California NanoSystems Institute (CNSI), University of California, Los Angeles (UCLA), Los Angeles, CA, USA
| | - Dean Scholl
- Pylum Biosciences, 100 Kimball Way S. San Francisco, CA 94080, USA
| | - Jeff F. Miller
- Department of Microbiology, Immunology and Molecular Genetics, University of California, Los Angeles (UCLA), Los Angeles, CA, USA
- The California NanoSystems Institute (CNSI), University of California, Los Angeles (UCLA), Los Angeles, CA, USA
| | - Z. Hong Zhou
- Department of Microbiology, Immunology and Molecular Genetics, University of California, Los Angeles (UCLA), Los Angeles, CA, USA
- The California NanoSystems Institute (CNSI), University of California, Los Angeles (UCLA), Los Angeles, CA, USA
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5
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Sonani RR, Palmer LK, Esteves NC, Horton AA, Sebastian AL, Kelly RJ, Wang F, Kreutzberger MAB, Russell WK, Leiman PG, Scharf BE, Egelman EH. An extensive disulfide bond network prevents tail contraction in Agrobacterium tumefaciens phage Milano. Nat Commun 2024; 15:756. [PMID: 38272938 PMCID: PMC10811340 DOI: 10.1038/s41467-024-44959-z] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/06/2023] [Accepted: 01/10/2024] [Indexed: 01/27/2024] Open
Abstract
A contractile sheath and rigid tube assembly is a widespread apparatus used by bacteriophages, tailocins, and the bacterial type VI secretion system to penetrate cell membranes. In this mechanism, contraction of an external sheath powers the motion of an inner tube through the membrane. The structure, energetics, and mechanism of the machinery imply rigidity and straightness. The contractile tail of Agrobacterium tumefaciens bacteriophage Milano is flexible and bent to varying degrees, which sets it apart from other contractile tail-like systems. Here, we report structures of the Milano tail including the sheath-tube complex, baseplate, and putative receptor-binding proteins. The flexible-to-rigid transformation of the Milano tail upon contraction can be explained by unique electrostatic properties of the tail tube and sheath. All components of the Milano tail, including sheath subunits, are crosslinked by disulfides, some of which must be reduced for contraction to occur. The putative receptor-binding complex of Milano contains a tailspike, a tail fiber, and at least two small proteins that form a garland around the distal ends of the tailspikes and tail fibers. Despite being flagellotropic, Milano lacks thread-like tail filaments that can wrap around the flagellum, and is thus likely to employ a different binding mechanism.
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Affiliation(s)
- Ravi R Sonani
- Department of Biochemistry and Molecular Genetics, University of Virginia School of Medicine, Charlottesville, VA, 22903, USA
| | - Lee K Palmer
- Mass Spectrometry Facility, University of Texas Medical Branch, Galveston, TX, 77555, USA
| | - Nathaniel C Esteves
- Department of Biological Sciences, Virginia Tech, Blacksburg, VA, 24061, USA
| | - Abigail A Horton
- Department of Biological Sciences, Virginia Tech, Blacksburg, VA, 24061, USA
| | - Amanda L Sebastian
- Department of Biological Sciences, Virginia Tech, Blacksburg, VA, 24061, USA
| | - Rebecca J Kelly
- Department of Biological Sciences, Virginia Tech, Blacksburg, VA, 24061, USA
| | - Fengbin Wang
- Department of Biochemistry and Molecular Genetics, University of Virginia School of Medicine, Charlottesville, VA, 22903, USA
- Department of Biochemistry and Molecular Genetics, University of Alabama at Birmingham, Birmingham, AL, 35233, USA
| | - Mark A B Kreutzberger
- Department of Biochemistry and Molecular Genetics, University of Virginia School of Medicine, Charlottesville, VA, 22903, USA
| | - William K Russell
- Mass Spectrometry Facility, University of Texas Medical Branch, Galveston, TX, 77555, USA
| | - Petr G Leiman
- Department of Biochemistry and Molecular Biology, University of Texas Medical Branch, Galveston, TX, 77555, USA.
| | - Birgit E Scharf
- Department of Biological Sciences, Virginia Tech, Blacksburg, VA, 24061, USA.
| | - Edward H Egelman
- Department of Biochemistry and Molecular Genetics, University of Virginia School of Medicine, Charlottesville, VA, 22903, USA.
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6
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Mei M, Pheng P, Kurzeja-Edwards D, Diggle SP. High prevalence of lipopolysaccharide mutants and R2-pyocin susceptible variants in Pseudomonas aeruginosa populations sourced from cystic fibrosis lung infections. Microbiol Spectr 2023; 11:e0177323. [PMID: 37877708 PMCID: PMC10714928 DOI: 10.1128/spectrum.01773-23] [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: 05/01/2023] [Accepted: 09/15/2023] [Indexed: 10/26/2023] Open
Abstract
IMPORTANCE Cystic fibrosis (CF) patients often experience chronic, debilitating lung infections caused by antibiotic-resistant Pseudomonas aeruginosa, contributing to antimicrobial resistance (AMR). The genetic and phenotypic diversity of P. aeruginosa populations in CF lungs raises questions about their susceptibility to non-traditional antimicrobials, like bacteriocins. In this study, we focused on R-pyocins, a type of bacteriocin with high potency and a narrow killing spectrum. Our findings indicate that a large number of infectious CF variants are susceptible to R2-pyocins, even within diverse bacterial populations, supporting their potential use as therapeutic agents. The absence of a clear correlation between lipopolysaccharide (LPS) phenotypes and R-pyocin susceptibility suggests that LPS packing density may play a significant role in R-pyocin susceptibility among CF variants. Understanding the relationship between LPS phenotypes and R-pyocin susceptibility is crucial for developing effective treatments for these chronic infections.
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Affiliation(s)
- Madeline Mei
- School of Biological Sciences, Center for Microbial Dynamics and Infection, Georgia Institute of Technology, Atlanta, Georgia, USA
- Department of Pediatrics, Division of Pulmonary, Allergy and Immunology, Cystic Fibrosis, and Sleep, Emory University School of Medicine, Atlanta, Georgia, USA
- Emory+Children’s Center for Cystic Fibrosis and Airway Disease Research, Emory University School of Medicine, Atlanta, Georgia, USA
| | - Preston Pheng
- School of Biological Sciences, Center for Microbial Dynamics and Infection, Georgia Institute of Technology, Atlanta, Georgia, USA
| | - Detriana Kurzeja-Edwards
- School of Biological Sciences, Center for Microbial Dynamics and Infection, Georgia Institute of Technology, Atlanta, Georgia, USA
| | - Stephen P. Diggle
- School of Biological Sciences, Center for Microbial Dynamics and Infection, Georgia Institute of Technology, Atlanta, Georgia, USA
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7
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Borowicz M, Krzyżanowska DM, Narajczyk M, Sobolewska M, Rajewska M, Czaplewska P, Węgrzyn K, Czajkowski R. Soft rot pathogen Dickeya dadantii 3937 produces tailocins resembling the tails of Peduovirus P2. Front Microbiol 2023; 14:1307349. [PMID: 38098664 PMCID: PMC10719855 DOI: 10.3389/fmicb.2023.1307349] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/04/2023] [Accepted: 11/14/2023] [Indexed: 12/17/2023] Open
Abstract
Tailocins are nanomolecular machines with bactericidal activity. They are produced by bacteria to contribute to fitness in mixed communities, and hence, they play a critical role in their ecology in a variety of habitats. Here, we characterized the new tailocin produced by Dickeya dadantii strain 3937, a well-characterized member of plant pathogenic Soft Rot Pectobacteriaceae (SRP). Tailocins induced in D. dadantii were ca. 166 nm long tubes surrounded by contractive sheaths with baseplates having tail fibers at one end. A 22-kb genomic cluster involved in their synthesis and having high homology to the cluster coding for the tail of the Peduovirus P2 was identified. The D. dadantii tailocins, termed dickeyocins P2D1 (phage P2-like dickeyocin 1), were resistant to inactivation by pH (3.5-12), temperature (4-50°C), and elevated osmolarity (NaCl concentration: 0.01-1 M). P2D1 could kill a variety of different Dickeya spp. but not any strain of Pectobacterium spp. tested and were not toxic to Caenorhabditis elegans.
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Affiliation(s)
- Marcin Borowicz
- Laboratory of Biologically Active Compounds, Intercollegiate Faculty of Biotechnology of UG and MUG, University of Gdańsk, Gdańsk, Poland
| | - Dorota M. Krzyżanowska
- Laboratory of Biologically Active Compounds, Intercollegiate Faculty of Biotechnology of UG and MUG, University of Gdańsk, Gdańsk, Poland
| | - Magdalena Narajczyk
- Bioimaging Laboratory, Faculty of Biology, University of Gdańsk, Gdańsk, Poland
| | - Marta Sobolewska
- Laboratory of Biologically Active Compounds, Intercollegiate Faculty of Biotechnology of UG and MUG, University of Gdańsk, Gdańsk, Poland
| | - Magdalena Rajewska
- Laboratory of Plant Microbiology, Intercollegiate Faculty of Biotechnology of UG and MUG, University of Gdańsk, Gdańsk, Poland
| | - Paulina Czaplewska
- Laboratory of Mass Spectrometry-Core Facility Laboratories, Intercollegiate Faculty of Biotechnology of UG and MUG, University of Gdańsk, Gdańsk, Poland
| | - Katarzyna Węgrzyn
- Laboratory of Molecular Biology, Intercollegiate Faculty of Biotechnology of UG and MUG, University of Gdańsk, Gdańsk, Poland
| | - Robert Czajkowski
- Laboratory of Biologically Active Compounds, Intercollegiate Faculty of Biotechnology of UG and MUG, University of Gdańsk, Gdańsk, Poland
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8
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Woudstra C, Sørensen AN, Brøndsted L. Engineering of Salmonella Phages into Novel Antimicrobial Tailocins. Cells 2023; 12:2637. [PMID: 37998371 PMCID: PMC10670071 DOI: 10.3390/cells12222637] [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: 10/05/2023] [Revised: 11/06/2023] [Accepted: 11/09/2023] [Indexed: 11/25/2023] Open
Abstract
Due to the extensive use of antibiotics, the increase of infections caused by antibiotic-resistant bacteria is now a global health concern. Phages have proven useful for treating bacterial infections and represent a promising alternative or complement to antibiotic treatment. Yet, other alternatives exist, such as bacteria-produced non-replicative protein complexes that can kill their targeted bacteria by puncturing their membrane (Tailocins). To expand the repertoire of Tailocins available, we suggest a new approach that transforms phages into Tailocins. Here, we genetically engineered the virulent Ackermannviridae phage S117, as well as temperate phages Fels-1, -2 and Gifsy-1 and -2, targeting the food pathogen Salmonella, by deleting the portal vertex or major capsid gene using CRISPR-Cas9. We report the production of Tailocin particles from engineered virulent and temperate phages able to kill their native host. Our work represents a steppingstone that taps into the huge diversity of phages and transforms them into versatile puncturing new antimicrobials.
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Affiliation(s)
| | | | - Lone Brøndsted
- Department of Veterinary and Animal Sciences, University of Copenhagen, 1870 Frederiksberg C, Denmark; (C.W.); (A.N.S.)
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9
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Heiman CM, Vacheron J, Keel C. Evolutionary and ecological role of extracellular contractile injection systems: from threat to weapon. Front Microbiol 2023; 14:1264877. [PMID: 37886057 PMCID: PMC10598620 DOI: 10.3389/fmicb.2023.1264877] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/21/2023] [Accepted: 09/26/2023] [Indexed: 10/28/2023] Open
Abstract
Contractile injection systems (CISs) are phage tail-related structures that are encoded in many bacterial genomes. These devices encompass the cell-based type VI secretion systems (T6SSs) as well as extracellular CISs (eCISs). The eCISs comprise the R-tailocins produced by various bacterial species as well as related phage tail-like structures such as the antifeeding prophages (Afps) of Serratia entomophila, the Photorhabdus virulence cassettes (PVCs), and the metamorphosis-associated contractile structures (MACs) of Pseudoalteromonas luteoviolacea. These contractile structures are released into the extracellular environment upon suicidal lysis of the producer cell and play important roles in bacterial ecology and evolution. In this review, we specifically portray the eCISs with a focus on the R-tailocins, sketch the history of their discovery and provide insights into their evolution within the bacterial host, their structures and how they are assembled and released. We then highlight ecological and evolutionary roles of eCISs and conceptualize how they can influence and shape bacterial communities. Finally, we point to their potential for biotechnological applications in medicine and agriculture.
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Affiliation(s)
- Clara Margot Heiman
- Department of Fundamental Microbiology, University of Lausanne, Lausanne, Switzerland
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10
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Mei M, Pheng P, Kurzeja-Edwards D, Diggle SP. High prevalence of lipopolysaccharide mutants and R2-Pyocin susceptible variants in Pseudomonas aeruginosa populations sourced from cystic fibrosis lung infections. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.04.26.538445. [PMID: 37163048 PMCID: PMC10168318 DOI: 10.1101/2023.04.26.538445] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/11/2023]
Abstract
Chronic, highly antibiotic-resistant infections in cystic fibrosis (CF) lungs contribute to increasing morbidity and mortality. Pseudomonas aeruginosa, a common CF pathogen, exhibits resistance to multiple antibiotics, contributing to antimicrobial resistance (AMR). These bacterial populations display genetic and phenotypic diversity, but it is unclear how this diversity affects susceptibility to bacteriocins. R-pyocins, i.e. bacteriocins produced by P. aeruginosa, are phage tail-like antimicrobials. R-pyocins have potential as antimicrobials, however recent research suggests the diversity of P. aeruginosa variants within CF lung infections leads to varying susceptibility to R-pyocins. This variation may be linked to changes in lipopolysaccharide (LPS), acting as the R-pyocin receptor. Currently, it is unknown how frequently R-pyocin-susceptible strains are in chronic CF lung infection, particularly when considering the heterogeneity within these strains. In this study, we tested R2-pyocin susceptibility of 139 P. aeruginosa variants from 17 sputum samples of seven CF patients and analyzed LPS phenotypes. We found that 83% of sputum samples did not have R2-pyocin-resistant variants, while nearly all samples contained susceptible variants. there was no correlation between LPS phenotype and R2-pyocin susceptibility, though we estimate that about 76% of sputum-derived variants lack an O-specific antigen, 40% lack a common antigen, and 24% have altered LPS cores. The absence of a correlation between LPS phenotype and R-pyocin susceptibility suggests LPS packing density may play a significant role in R-pyocin susceptibility among CF variants. Our research supports the potential of R-pyocins as therapeutic agents, as many infectious CF variants are susceptible to R2-pyocins, even within diverse bacterial populations.
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Affiliation(s)
- Madeline Mei
- Center for Microbial Dynamics and Infection, School of Biological Sciences, Georgia Institute of Technology, Atlanta, Georgia, USA
- Department of Pediatrics, Division of Pulmonary, Allergy and Immunology, Cystic Fibrosis, and Sleep, Emory University School of Medicine, Atlanta, Georgia, USA
- Emory+Children’s Center for Cystic Fibrosis and Airway Disease Research, Emory University School of Medicine, Atlanta, Georgia, USA
| | - Preston Pheng
- Center for Microbial Dynamics and Infection, School of Biological Sciences, Georgia Institute of Technology, Atlanta, Georgia, USA
| | - Detriana Kurzeja-Edwards
- Center for Microbial Dynamics and Infection, School of Biological Sciences, Georgia Institute of Technology, Atlanta, Georgia, USA
| | - Stephen P. Diggle
- Center for Microbial Dynamics and Infection, School of Biological Sciences, Georgia Institute of Technology, Atlanta, Georgia, USA
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11
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Wang Z, Fokine A, Guo X, Jiang W, Rossmann MG, Kuhn RJ, Luo ZH, Klose T. Structure of Vibrio Phage XM1, a Simple Contractile DNA Injection Machine. Viruses 2023; 15:1673. [PMID: 37632015 PMCID: PMC10457771 DOI: 10.3390/v15081673] [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: 06/23/2023] [Revised: 07/26/2023] [Accepted: 07/26/2023] [Indexed: 08/27/2023] Open
Abstract
Antibiotic resistance poses a growing risk to public health, requiring new tools to combat pathogenic bacteria. Contractile injection systems, including bacteriophage tails, pyocins, and bacterial type VI secretion systems, can efficiently penetrate cell envelopes and become potential antibacterial agents. Bacteriophage XM1 is a dsDNA virus belonging to the Myoviridae family and infecting Vibrio bacteria. The XM1 virion, made of 18 different proteins, consists of an icosahedral head and a contractile tail, terminated with a baseplate. Here, we report cryo-EM reconstructions of all components of the XM1 virion and describe the atomic structures of 14 XM1 proteins. The XM1 baseplate is composed of a central hub surrounded by six wedge modules to which twelve spikes are attached. The XM1 tail contains a fewer number of smaller proteins compared to other reported phage baseplates, depicting the minimum requirements for building an effective cell-envelope-penetrating machine. We describe the tail sheath structure in the pre-infection and post-infection states and its conformational changes during infection. In addition, we report, for the first time, the in situ structure of the phage neck region to near-atomic resolution. Based on these structures, we propose mechanisms of virus assembly and infection.
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Affiliation(s)
- Zhiqing Wang
- Department of Biological Sciences, Purdue University, West Lafayette, IN 47907, USA
- National Cryo-EM Facility, Frederick National Laboratory for Cancer Research, Leidos Biomedical Research Inc., Frederick, MD 21701, USA
| | - Andrei Fokine
- Department of Biological Sciences, Purdue University, West Lafayette, IN 47907, USA
| | - Xinwu Guo
- Sansure Biotech Inc., Changsha 410205, China
| | - Wen Jiang
- Department of Biological Sciences, Purdue University, West Lafayette, IN 47907, USA
| | - Michael G. Rossmann
- Department of Biological Sciences, Purdue University, West Lafayette, IN 47907, USA
| | - Richard J. Kuhn
- Department of Biological Sciences, Purdue University, West Lafayette, IN 47907, USA
| | - Zhu-Hua Luo
- Key Laboratory of Marine Biogenetic Resources, Third Institute of Oceanography, Ministry of Natural Resources, Xiamen 361005, China
- School of Marine Sciences, Nanjing University of Information Science and Technology, Nanjing 210044, China
| | - Thomas Klose
- Department of Biological Sciences, Purdue University, West Lafayette, IN 47907, USA
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12
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Li F, Hou CFD, Lokareddy RK, Yang R, Forti F, Briani F, Cingolani G. High-resolution cryo-EM structure of the Pseudomonas bacteriophage E217. Nat Commun 2023; 14:4052. [PMID: 37422479 PMCID: PMC10329688 DOI: 10.1038/s41467-023-39756-z] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/05/2023] [Accepted: 06/27/2023] [Indexed: 07/10/2023] Open
Abstract
E217 is a Pseudomonas phage used in an experimental cocktail to eradicate cystic fibrosis-associated Pseudomonas aeruginosa. Here, we describe the structure of the whole E217 virion before and after DNA ejection at 3.1 Å and 4.5 Å resolution, respectively, determined using cryogenic electron microscopy (cryo-EM). We identify and build de novo structures for 19 unique E217 gene products, resolve the tail genome-ejection machine in both extended and contracted states, and decipher the complete architecture of the baseplate formed by 66 polypeptide chains. We also determine that E217 recognizes the host O-antigen as a receptor, and we resolve the N-terminal portion of the O-antigen-binding tail fiber. We propose that E217 design principles presented in this paper are conserved across PB1-like Myoviridae phages of the Pbunavirus genus that encode a ~1.4 MDa baseplate, dramatically smaller than the coliphage T4.
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Affiliation(s)
- Fenglin Li
- Department of Biochemistry and Molecular Biology, Thomas Jefferson University, 1020 Locust Street, Philadelphia, PA, 19107, USA
| | - Chun-Feng David Hou
- Department of Biochemistry and Molecular Biology, Thomas Jefferson University, 1020 Locust Street, Philadelphia, PA, 19107, USA
| | - Ravi K Lokareddy
- Department of Biochemistry and Molecular Biology, Thomas Jefferson University, 1020 Locust Street, Philadelphia, PA, 19107, USA
| | - Ruoyu Yang
- Department of Biochemistry and Molecular Biology, Thomas Jefferson University, 1020 Locust Street, Philadelphia, PA, 19107, USA
| | - Francesca Forti
- Dipartimento di Bioscienze, Università degli Studi di Milano, Milan, Italy
| | - Federica Briani
- Dipartimento di Bioscienze, Università degli Studi di Milano, Milan, Italy.
| | - Gino Cingolani
- Department of Biochemistry and Molecular Biology, Thomas Jefferson University, 1020 Locust Street, Philadelphia, PA, 19107, USA.
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13
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He W, Wu K, Ouyang Z, Bai Y, Luo W, Wu D, An H, Guo Y, Jiao M, Qin Q, Zhang J, Wu Y, She J, Hwang PM, Zheng F, Zhu L, Wen Y. Structure and assembly of type VI secretion system cargo delivery vehicle. Cell Rep 2023; 42:112781. [PMID: 37421630 DOI: 10.1016/j.celrep.2023.112781] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/23/2022] [Revised: 05/06/2023] [Accepted: 06/25/2023] [Indexed: 07/10/2023] Open
Abstract
Type VI secretion system is widely used in Gram-negative bacteria for injecting toxic effectors into neighboring prokaryotic or eukaryotic cells. Various effectors can be loaded onto the T6SS delivery tube via its core components: Hcp, VgrG, or PAAR. Here, we report 2.8-Å resolution cryo-EM structure of intact T6SS Hcp5-VgrG-PAAR cargo delivery system and crystal structure of unbound Hcp5 from B. fragilis NCTC 9343. Loading of Hcp5 hexameric ring onto VgrG causes expansion of its inner cavity and external surface, explaining how structural changes could be propagated to regulate co-polymerization and surrounding contractile sheath. High-affinity binding between Hcp and VgrG causes entropically unfavorable structuring of long loops. Furthermore, interactions between VgrG trimer and Hcp hexamer are asymmetric, with three of the six Hcp monomers exhibiting a major loop flip. Our study provides insights into the assembly, loading, and firing of T6SS nanomachine that contributes to bacterial inter-species competition and host interactions.
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Affiliation(s)
- Wenbo He
- Center for Microbiome Research of Med-X Institute, Shaanxi Provincial Key Laboratory of Sepsis in Critical Care Medicine, The First Affiliated Hospital, Xi'an Jiaotong University, Xi'an 710061, China
| | - Ke Wu
- Ministry of Education Key Laboratory of Cell Activities and Stress Adaptations, School of Life Sciences, Lanzhou University, Lanzhou 730000, China
| | - Zhenlin Ouyang
- Center for Microbiome Research of Med-X Institute, Shaanxi Provincial Key Laboratory of Sepsis in Critical Care Medicine, The First Affiliated Hospital, Xi'an Jiaotong University, Xi'an 710061, China
| | - Yixin Bai
- Center for Microbiome Research of Med-X Institute, Shaanxi Provincial Key Laboratory of Sepsis in Critical Care Medicine, The First Affiliated Hospital, Xi'an Jiaotong University, Xi'an 710061, China
| | - Wen Luo
- Department of Oncology, The Second Affiliated Hospital of Xi'an Jiaotong University, Xi'an, Shaanxi, China
| | - Di Wu
- Ministry of Education Key Laboratory of Cell Activities and Stress Adaptations, School of Life Sciences, Lanzhou University, Lanzhou 730000, China
| | - Hao An
- Ministry of Education Key Laboratory of Cell Activities and Stress Adaptations, School of Life Sciences, Lanzhou University, Lanzhou 730000, China
| | - Yucheng Guo
- The Key Laboratory of Environment and Genes Related to Disease of Ministry of Education Health Science Center, Xi'an Jiaotong University, Xi'an 710061, China
| | - Min Jiao
- Center for Microbiome Research of Med-X Institute, Shaanxi Provincial Key Laboratory of Sepsis in Critical Care Medicine, The First Affiliated Hospital, Xi'an Jiaotong University, Xi'an 710061, China
| | - Qian Qin
- Center for Microbiome Research of Med-X Institute, Shaanxi Provincial Key Laboratory of Sepsis in Critical Care Medicine, The First Affiliated Hospital, Xi'an Jiaotong University, Xi'an 710061, China
| | - Jiaxin Zhang
- The Key Laboratory of Environment and Genes Related to Disease of Ministry of Education Health Science Center, Xi'an Jiaotong University, Xi'an 710061, China
| | - Yi Wu
- The Key Laboratory of Environment and Genes Related to Disease of Ministry of Education Health Science Center, Xi'an Jiaotong University, Xi'an 710061, China
| | - Junjun She
- Center for Microbiome Research of Med-X Institute, Shaanxi Provincial Key Laboratory of Sepsis in Critical Care Medicine, The First Affiliated Hospital, Xi'an Jiaotong University, Xi'an 710061, China
| | - Peter M Hwang
- Department of Biochemistry, Faculty of Medicine & Dentistry, Edmonton, AB T6G 2R3, Canada
| | - Fang Zheng
- The Key Laboratory of Environment and Genes Related to Disease of Ministry of Education Health Science Center, Xi'an Jiaotong University, Xi'an 710061, China
| | - Li Zhu
- Ministry of Education Key Laboratory of Cell Activities and Stress Adaptations, School of Life Sciences, Lanzhou University, Lanzhou 730000, China; Ministry of Education Key Laboratory of Cell Activities and Stress Adaptations, School of Life Sciences, Electron Microscopy Centre of Lanzhou University, Lanzhou University, Lanzhou 730000, China.
| | - Yurong Wen
- Center for Microbiome Research of Med-X Institute, Shaanxi Provincial Key Laboratory of Sepsis in Critical Care Medicine, The First Affiliated Hospital, Xi'an Jiaotong University, Xi'an 710061, China; The Key Laboratory of Environment and Genes Related to Disease of Ministry of Education Health Science Center, Xi'an Jiaotong University, Xi'an 710061, China.
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14
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Allsopp LP, Bernal P. Killing in the name of: T6SS structure and effector diversity. MICROBIOLOGY (READING, ENGLAND) 2023; 169:001367. [PMID: 37490402 PMCID: PMC10433429 DOI: 10.1099/mic.0.001367] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/23/2023] [Accepted: 07/12/2023] [Indexed: 07/27/2023]
Abstract
The life of bacteria is challenging, to endure bacteria employ a range of mechanisms to optimize their environment, including deploying the type VI secretion system (T6SS). Acting as a bacterial crossbow, this system delivers effectors responsible for subverting host cells, killing competitors and facilitating general secretion to access common goods. Due to its importance, this lethal machine has been evolutionarily maintained, disseminated and specialized to fulfil these vital functions. In fact, T6SS structural clusters are present in over 25 % of Gram-negative bacteria, varying in number from one to six different genetic clusters per organism. Since its discovery in 2006, research on the T6SS has rapidly progressed, yielding remarkable breakthroughs. The identification and characterization of novel components of the T6SS, combined with biochemical and structural studies, have revealed fascinating mechanisms governing its assembly, loading, firing and disassembly processes. Recent findings have also demonstrated the efficacy of this system against fungal and Gram-positive cells, expanding its scope. Ongoing research continues to uncover an extensive and expanding repertoire of T6SS effectors, the genuine mediators of T6SS function. These studies are shedding light on new aspects of the biology of prokaryotic and eukaryotic organisms. This review provides a comprehensive overview of the T6SS, highlighting recent discoveries of its structure and the diversity of its effectors. Additionally, it injects a personal perspective on avenues for future research, aiming to deepen our understanding of this combative system.
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Affiliation(s)
- Luke P. Allsopp
- National Heart and Lung Institute, Imperial College London, London, UK
| | - Patricia Bernal
- Departamento de Microbiología, Facultad de Biología, Universidad de Sevilla, Sevilla 41012, Spain
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15
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Yang F, Wang L, Zhou J, Xiao H, Liu H. In Situ Structures of the Ultra-Long Extended and Contracted Tail of Myoviridae Phage P1. Viruses 2023; 15:1267. [PMID: 37376567 DOI: 10.3390/v15061267] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/29/2023] [Revised: 05/20/2023] [Accepted: 05/27/2023] [Indexed: 06/29/2023] Open
Abstract
The Myoviridae phage tail is a common component of contractile injection systems (CISs), essential for exerting contractile function and facilitating membrane penetration of the inner tail tube. The near-atomic resolution structures of the Myoviridae tail have been extensively studied, but the dynamic conformational changes before and after contraction and the associated molecular mechanism are still unclear. Here, we present the extended and contracted intact tail-structures of Myoviridae phage P1 by cryo-EM. The ultra-long tail of P1, 2450 Å in length, consists of a neck, a tail terminator, 53 repeated tail sheath rings, 53 repeated tube rings, and a baseplate. The sheath of the contracted tail shrinks by approximately 55%, resulting in the separation of the inner rigid tail tube from the sheath. The extended and contracted tails were further resolved by local reconstruction at 3.3 Å and 3.9 Å resolutions, respectively, allowing us to build the atomic models of the tail terminator protein gp24, the tube protein BplB, and the sheath protein gp22 for the extended tail, and of the sheath protein gp22 for the contracted tail. Our atomic models reveal the complex interaction network in the ultra-long Myoviridae tail and the novel conformational changes of the tail sheath between extended and contracted states. Our structures provide insights into the contraction and stabilization mechanisms of the Myoviridae tail.
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Affiliation(s)
- Fan Yang
- Institute of Interdisciplinary Studies, Key Laboratory for Matter Microstructure and Function of Hunan Province, Key Laboratory of Low-Dimensional Quantum Structures and Quantum Control, Hunan Normal University, Changsha 410082, China
| | - Liwen Wang
- Institute of Interdisciplinary Studies, Key Laboratory for Matter Microstructure and Function of Hunan Province, Key Laboratory of Low-Dimensional Quantum Structures and Quantum Control, Hunan Normal University, Changsha 410082, China
| | - Junquan Zhou
- Institute of Interdisciplinary Studies, Key Laboratory for Matter Microstructure and Function of Hunan Province, Key Laboratory of Low-Dimensional Quantum Structures and Quantum Control, Hunan Normal University, Changsha 410082, China
| | - Hao Xiao
- Institute of Interdisciplinary Studies, Key Laboratory for Matter Microstructure and Function of Hunan Province, Key Laboratory of Low-Dimensional Quantum Structures and Quantum Control, Hunan Normal University, Changsha 410082, China
- State Key Laboratory of Infectious Disease Prevention and Control, National Institute for Viral Disease Control and Prevention, Chinese Center for Disease Control and Prevention, Beijing 100052, China
| | - Hongrong Liu
- Institute of Interdisciplinary Studies, Key Laboratory for Matter Microstructure and Function of Hunan Province, Key Laboratory of Low-Dimensional Quantum Structures and Quantum Control, Hunan Normal University, Changsha 410082, China
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16
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Cytoplasmic contractile injection systems mediate cell death in Streptomyces. Nat Microbiol 2023; 8:711-726. [PMID: 36894633 PMCID: PMC10066040 DOI: 10.1038/s41564-023-01341-x] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/12/2022] [Accepted: 02/10/2023] [Indexed: 03/11/2023]
Abstract
Contractile injection systems (CIS) are bacteriophage tail-like structures that mediate bacterial cell-cell interactions. While CIS are highly abundant across diverse bacterial phyla, representative gene clusters in Gram-positive organisms remain poorly studied. Here we characterize a CIS in the Gram-positive multicellular model organism Streptomyces coelicolor and show that, in contrast to most other CIS, S. coelicolor CIS (CISSc) mediate cell death in response to stress and impact cellular development. CISSc are expressed in the cytoplasm of vegetative hyphae and are not released into the medium. Our cryo-electron microscopy structure enabled the engineering of non-contractile and fluorescently tagged CISSc assemblies. Cryo-electron tomography showed that CISSc contraction is linked to reduced cellular integrity. Fluorescence light microscopy furthermore revealed that functional CISSc mediate cell death upon encountering different types of stress. The absence of functional CISSc had an impact on hyphal differentiation and secondary metabolite production. Finally, we identified three putative effector proteins, which when absent, phenocopied other CISSc mutants. Our results provide new functional insights into CIS in Gram-positive organisms and a framework for studying novel intracellular roles, including regulated cell death and life-cycle progression in multicellular bacteria.
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17
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R-Type Fonticins Produced by Pragia fontium Form Large Pores with High Conductance. J Bacteriol 2023; 205:e0031522. [PMID: 36541812 PMCID: PMC9879110 DOI: 10.1128/jb.00315-22] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022] Open
Abstract
Fonticins are phage tail-like bacteriocins produced by the Gram-negative bacterium Pragia fontium from the family Budviciaceae. This bacterium produces contractile-type particles that adsorb on the surface of sensitive bacteria and penetrate the cell wall, probably during contraction, in a way similar to the type VI secretion system. We characterized the pore-forming activity of fonticins using both living cells and in vitro model membranes. Using a potassium leakage assay, we show that fonticins are able to permeabilize sensitive cells. On black lipid membranes, single-pore conductance is about 0.78 nS in 1 M NaCl and appears to be linearly dependent on the increasing molar strength of NaCl solution, which is a property of considerably large pores. In agreement with these findings, fonticins are not ion selective for Na+, K+, and Cl-. Polyethylene glycol 3350 (PEG 3350) molecules of about 3.5 nm in diameter can enter the fonticin pore lumen, whereas the larger molecules cannot pass the pore. The size of fonticin pores was confirmed by transmission electron microscopy. The terminal membrane-piercing complex of the fonticin tube probably creates a selective barrier restricting passage of macromolecules. IMPORTANCE Phage tail-like bacteriocins are now the subject of research as potent antibacterial agents due to their narrow host specificity and single-hit mode of action. In this work, we focused on the structure and mode of action of fonticins. According to some theories, related particles were initially adapted for passage of double-stranded DNA (dsDNA) molecules, but fonticins changed their function during the evolution; they are able to form large pores through the bacterial envelope of Gram-negative bacteria. As various pore-forming proteins are extensively used for nanopore sequencing and stochastic sensing, we decided to investigate the pore-forming properties of fonticin protein complexes on artificial lipid membranes. Our research revealed remarkable structural properties of these particles that may have a potential application as a nanodevice.
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18
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Ouyang R, Costa AR, Cassidy CK, Otwinowska A, Williams VCJ, Latka A, Stansfeld PJ, Drulis-Kawa Z, Briers Y, Pelt DM, Brouns SJJ, Briegel A. High-resolution reconstruction of a Jumbo-bacteriophage infecting capsulated bacteria using hyperbranched tail fibers. Nat Commun 2022; 13:7241. [PMID: 36433970 PMCID: PMC9700779 DOI: 10.1038/s41467-022-34972-5] [Citation(s) in RCA: 12] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/13/2022] [Accepted: 11/14/2022] [Indexed: 11/26/2022] Open
Abstract
The Klebsiella jumbo myophage ϕKp24 displays an unusually complex arrangement of tail fibers interacting with a host cell. In this study, we combine cryo-electron microscopy methods, protein structure prediction methods, molecular simulations, microbiological and machine learning approaches to explore the capsid, tail, and tail fibers of ϕKp24. We determine the structure of the capsid and tail at 4.1 Å and 3.0 Å resolution. We observe the tail fibers are branched and rearranged dramatically upon cell surface attachment. This complex configuration involves fourteen putative tail fibers with depolymerase activity that provide ϕKp24 with the ability to infect a broad panel of capsular polysaccharide (CPS) types of Klebsiella pneumoniae. Our study provides structural and functional insight into how ϕKp24 adapts to the variable surfaces of capsulated bacterial pathogens, which is useful for the development of phage therapy approaches against pan-drug resistant K. pneumoniae strains.
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Affiliation(s)
- Ruochen Ouyang
- grid.43169.390000 0001 0599 1243MOE Key Laboratory for Nonequilibrium Synthesis and Modulation of Condensed Matter, School of Physics, Xi’an Jiaotong University, Xianning West Road 28, Xi’an, 710049 China ,grid.5132.50000 0001 2312 1970Department of Microbial Sciences, Institute of Biology, Leiden University, Sylviusweg 72, 2333 BE Leiden, The Netherlands
| | - Ana Rita Costa
- grid.5292.c0000 0001 2097 4740Department of Bionanoscience, Delft University of Technology, Van der Maasweg 9, 2629 HZ Delft, The Netherlands ,grid.5292.c0000 0001 2097 4740Kavli Institute of Nanoscience, Delft, The Netherlands
| | - C. Keith Cassidy
- grid.4991.50000 0004 1936 8948Department of Biochemistry, University of Oxford, Oxford, UK
| | - Aleksandra Otwinowska
- grid.8505.80000 0001 1010 5103Department of Pathogen Biology and Immunology, University of Wroclaw, Przybyszewskiego 63-77, 51-148 Wroclaw, Poland
| | - Vera C. J. Williams
- grid.5132.50000 0001 2312 1970Department of Microbial Sciences, Institute of Biology, Leiden University, Sylviusweg 72, 2333 BE Leiden, The Netherlands
| | - Agnieszka Latka
- grid.8505.80000 0001 1010 5103Department of Pathogen Biology and Immunology, University of Wroclaw, Przybyszewskiego 63-77, 51-148 Wroclaw, Poland ,grid.5342.00000 0001 2069 7798Department of Biotechnology, Ghent University, Valentin Vaerwyckweg 1, 9000 Ghent, Belgium
| | - Phill J. Stansfeld
- grid.7372.10000 0000 8809 1613School of Life Sciences & Department of Chemistry, University of Warwick, Coventry, CV4 7AL UK
| | - Zuzanna Drulis-Kawa
- grid.8505.80000 0001 1010 5103Department of Pathogen Biology and Immunology, University of Wroclaw, Przybyszewskiego 63-77, 51-148 Wroclaw, Poland
| | - Yves Briers
- grid.5342.00000 0001 2069 7798Department of Biotechnology, Ghent University, Valentin Vaerwyckweg 1, 9000 Ghent, Belgium
| | - Daniël M. Pelt
- grid.5132.50000 0001 2312 1970Leiden Institute of Advanced Computer Science, Leiden University, Niels Bohrweg 1, 2333CA Leiden, The Netherlands
| | - Stan J. J. Brouns
- grid.5292.c0000 0001 2097 4740Department of Bionanoscience, Delft University of Technology, Van der Maasweg 9, 2629 HZ Delft, The Netherlands ,grid.5292.c0000 0001 2097 4740Kavli Institute of Nanoscience, Delft, The Netherlands
| | - Ariane Briegel
- grid.5132.50000 0001 2312 1970Department of Microbial Sciences, Institute of Biology, Leiden University, Sylviusweg 72, 2333 BE Leiden, The Netherlands
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19
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Bhattacharjee R, Nandi A, Sinha A, Kumar H, Mitra D, Mojumdar A, Patel P, Jha E, Mishra S, Rout PK, Panda PK, Suar M, Verma SK. Phage-tail-like bacteriocins as a biomedical platform to counter anti-microbial resistant pathogens. Biomed Pharmacother 2022; 155:113720. [PMID: 36162371 DOI: 10.1016/j.biopha.2022.113720] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/29/2022] [Revised: 09/15/2022] [Accepted: 09/19/2022] [Indexed: 11/25/2022] Open
Abstract
Phage Tail Like bacteriocins (PTLBs) has been an area of interest in the last couple of years owing to their varied application against multi-drug resistant (MDR), anti-microbial resistant (AMR) pathogens and their evolutionary link with the dsDNA virus and bacteriophages. PTLBs are defective phages derived from Myoviridae and Siphoviridae phages, PTLBs are distinguished into R-type (Rigid type) characterized by a non-flexible contractile nanotube resembling Myoviridae phage contractile tails, and F-type (Flexible type) with a flexible non-contractile rod-like structure similar to Siphoviridae phages. In this review, we have discussed the structural association, mechanism, and characterization of PTLBs. Moreover, we have elucidated the symbiotic biological function and application of PTLBs against MDR and XDR pathogens and highlighted the evolutionary role of PTLBs. The difficulties that must be overcome to implement PTLBs clinically are also discussed. It is imperative that these issues be addressed by academics in future studies before being implemented in clinical settings. This article is novel in its way as it will not only provide us with a gateway that acts as a novel strategy for scholars to mitigate and control the uprising issue of AMR pathogens but also promote the development of clinical studies for PTLBs.
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Affiliation(s)
- Rahul Bhattacharjee
- KIIT School of Biotechnology, KIIT University, Bhubaneswar 751024, Odisha, India
| | - Aditya Nandi
- KIIT School of Biotechnology, KIIT University, Bhubaneswar 751024, Odisha, India
| | - Adrija Sinha
- KIIT School of Biotechnology, KIIT University, Bhubaneswar 751024, Odisha, India
| | - Hrithik Kumar
- School of Biology, Indian Institute of Science Education and Research (IISER)-Thiruvananthapuram, Kerala 695551, India
| | - Disha Mitra
- University of Calcutta, 92, APC Road, Kolkata 700009, India
| | - Abhik Mojumdar
- Center for Research Equipment, Korea Basic Science Institute (KBSI), Ochang Center, Cheongju, Chungcheongbuk 28119, Republic of Korea; Department of Bio-Analytical Science, University of Science and Technology (UST), Daejeon 34113, Republic of Korea
| | - Paritosh Patel
- KIIT School of Biotechnology, KIIT University, Bhubaneswar 751024, Odisha, India
| | - Ealisha Jha
- KIIT School of Biotechnology, KIIT University, Bhubaneswar 751024, Odisha, India
| | - Suman Mishra
- KIIT School of Biotechnology, KIIT University, Bhubaneswar 751024, Odisha, India
| | - Prabhat Kumar Rout
- KIIT School of Biotechnology, KIIT University, Bhubaneswar 751024, Odisha, India
| | - Pritam Kumar Panda
- Condensed Matter Theory Group, Materials Theory Division, Department of Physics and Astronomy, Uppsala University, Box 516, SE-751 20 Uppsala, Sweden.
| | - Mrutyunjay Suar
- KIIT School of Biotechnology, KIIT University, Bhubaneswar 751024, Odisha, India.
| | - Suresh K Verma
- KIIT School of Biotechnology, KIIT University, Bhubaneswar 751024, Odisha, India; Condensed Matter Theory Group, Materials Theory Division, Department of Physics and Astronomy, Uppsala University, Box 516, SE-751 20 Uppsala, Sweden.
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20
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Abdelghafar YA, AbdelQadir YH, Motawea KR, Nasr SA, Omran HAM, Belal MM, Elhashash MM, AbdelAzim AA, Shah J. Efficacy and safety of fecal microbiota transplant in irritable bowel syndrome: An update based on meta‐analysis of randomized control trials. Health Sci Rep 2022; 5:e814. [PMID: 36110348 PMCID: PMC9466358 DOI: 10.1002/hsr2.814] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/27/2022] [Revised: 07/12/2022] [Accepted: 08/08/2022] [Indexed: 11/21/2022] Open
Abstract
Background and Aims Fecal microbiota transfer (FMT) is a potential treatment for irritable bowel syndrome (IBS). Several randomized trials have tested FMT effects using different routes of administration, doses, and sample sizes. We aim to assess the overall efficacy of FMT for IBS patients and the safety of the intervention. Methods We systematically searched four databases for randomized control trials that studied the efficacy and safety of FMT in IBS patients. Results We included 8 randomized trials (472 patients) that compared FMT with placebo in IBS patients. Pooled results showed no statistically significant difference between FMT and control groups in the overall change in IBS symptom severity (IBS‐SSS) at 1 month (p = 0.94), 3/4 months (p = 0.82), and at the end of trials (p = 0.67). No significant difference in the total number of respondents between the FMT and control groups (risk ratios = 1.84, [95% confidence interval (CI) = 0.82–2.65], p = 0.19). Although the oral route of administration showed a significant difference in the number of respondents (p = 0.004), there was no statistically significant difference in the IBS‐SSS when subgrouping the oral route of administration (mean difference = 47.57, [95% CI = −8.74–103.87], p = 0.10). Conclusion FMT is not an effective treatment to relieve all the symptoms of IBS. Even in the groups that showed relatively significant improvement after FMT, the effect was proven to wear off over time and the re‐administration carries a low success rate. Future research should consider different bacterial‐based interventions such as probiotics or specific antibiotics.
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Affiliation(s)
| | | | | | - Sara Amr Nasr
- Faculty of Medicine Alexandria University Alexandria Egypt
| | | | | | | | | | - Jaffer Shah
- New York State Department of Health New York NY USA
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21
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Atomic Structure of IglD Demonstrates Its Role as a Component of the Baseplate Complex of the Francisella Type VI Secretion System. mBio 2022; 13:e0127722. [PMID: 36036641 PMCID: PMC9600919 DOI: 10.1128/mbio.01277-22] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022] Open
Abstract
Francisella tularensis, a Tier 1 select agent of bioterrorism, contains a type VI secretion system (T6SS) encoded within the Francisella pathogenicity island (FPI), which is critical for its pathogenesis. Among the 18 proteins encoded by FPI is IglD, which is essential to Francisella’s intracellular growth and virulence, but neither its location within T6SS nor its functional role has been established. Here, we present the cryoEM structure of IglD from Francisella novicida and show that the Francisella IglD forms a homotrimer that is structurally homologous to the T6SS baseplate protein TssK in Escherichia coli. Each IglD monomer consists of an N-terminal β-sandwich domain, a 4-helix bundle domain, and a flexible C-terminal domain. While the overall folds of IglD and TssK are similar, the two structures differ in three aspects: the relative orientation between their β-sandwich and the 4-helix bundle domains; two insertion loops present in TssK’s β-sandwich domain; and, consequently, a lack of subunit-subunit interaction between insertion loops in the IglD trimer. Phylogenetic analysis indicates that IglD is genetically remote from the TssK orthologs in other T6SSs. While the other components of the Francisella baseplate are unknown, we conducted pulldown assays showing IglJ interacts with IglD and IglH, pointing to a model wherein IglD, IglH, and IglJ form the baseplate of the Francisella T6SS. Alanine substitution mutagenesis further established that IglD’s hydrophobic pocket in the N-terminal β-sandwich domain interacts with two loops of IglJ, reminiscent of the TssK-TssG interaction. These results form a framework for understanding the hitherto unexplored Francisella T6SS baseplate.
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Heiman CM, Maurhofer M, Calderon S, Dupasquier M, Marquis J, Keel C, Vacheron J. Pivotal role of O-antigenic polysaccharide display in the sensitivity against phage tail-like particles in environmental Pseudomonas kin competition. THE ISME JOURNAL 2022; 16:1683-1693. [PMID: 35273372 PMCID: PMC9213528 DOI: 10.1038/s41396-022-01217-8] [Citation(s) in RCA: 10] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 11/17/2021] [Revised: 02/16/2022] [Accepted: 02/18/2022] [Indexed: 11/09/2022]
Abstract
AbstractEnvironmental pseudomonads colonize various niches including insect and plant environments. When invading these environments, bacteria are confronted with the resident microbiota. To oppose with closely related strains, they rely on narrow-spectrum weaponry such as tailocins, i.e., phage tail-like particles. Little is known about the receptors for these tailocins especially among phylogenetically closely related species. Here, we studied the interaction between an R-tailocin from Pseudomonas protegens CHA0 and a targeted kin, Pseudomonas protegens Pf-5. Using genome-wide transposon insertion sequencing, we identified that lipopolysaccharides are involved in the sensitivity of Pf-5 towards the tailocin of CHA0. By generating Pf-5 lipopolysaccharide mutants and exposing them to extracted tailocin, we specified the two O-antigenic polysaccharides (O-PS) targeted by the tailocin. We affirmed the role of these O-PS through competition assays in vitro as well as in insects. Further, we demonstrate that O-PS are double-edge swords that are responsible for the sensitivity of P. protegens towards tailocins and phages produced by their kin, but shield bacteria from the immune system of the insect. Our results shed light on the trade-off that bacteria are confronted with, where specific O-PS decorations can both be of benefit or disadvantage depending on the host environment and its bacterial inhabitants.
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Sun W, Liang X, Zhu C, Xu Y, Ding Y, Huang YP. Regulation of maltocin synthesis in Stenotrophomonas maltophilia by positive and negative regulators. Res Microbiol 2022; 173:103956. [DOI: 10.1016/j.resmic.2022.103956] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/28/2022] [Revised: 04/25/2022] [Accepted: 05/05/2022] [Indexed: 11/30/2022]
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Xu J, Ericson CF, Lien YW, Rutaganira FUN, Eisenstein F, Feldmüller M, King N, Pilhofer M. Identification and structure of an extracellular contractile injection system from the marine bacterium Algoriphagus machipongonensis. Nat Microbiol 2022; 7:397-410. [PMID: 35165385 PMCID: PMC8894135 DOI: 10.1038/s41564-022-01059-2] [Citation(s) in RCA: 19] [Impact Index Per Article: 9.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/26/2021] [Accepted: 01/05/2022] [Indexed: 12/11/2022]
Abstract
Contractile injection systems (CISs) are phage tail-like nanomachines, mediating bacterial cell–cell interactions as either type VI secretion systems (T6SSs) or extracellular CISs (eCISs). Bioinformatic studies uncovered a phylogenetic group of hundreds of putative CIS gene clusters that are highly diverse and widespread; however, only four systems have been characterized. Here we studied a putative CIS gene cluster in the marine bacterium Algoriphagus machipongonensis. Using an integrative approach, we show that the system is compatible with an eCIS mode of action. Our cryo-electron microscopy structure revealed several features that differ from those seen in other CISs: a ‘cap adaptor’ located at the distal end, a ‘plug’ exposed to the tube lumen, and a ‘cage’ formed by massive extensions of the baseplate. These elements are conserved in other CISs, and our genetic tools identified that they are required for assembly, cargo loading and function. Furthermore, our atomic model highlights specific evolutionary hotspots and will serve as a framework for understanding and re−engineering CISs. The characterization of an extracellular contractile injection system (eCIS) from the marine bacterium Algoriphagus machipongonensis (AlgoCIS) reveals structural features linked to the assembly and function of this nanomachine.
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Tall tails: cryo-electron microscopy of phage tail DNA ejection conduits. Biochem Soc Trans 2022; 50:459-22W. [PMID: 35129586 PMCID: PMC9022992 DOI: 10.1042/bst20210799] [Citation(s) in RCA: 9] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/08/2021] [Revised: 01/06/2022] [Accepted: 01/12/2022] [Indexed: 11/17/2022]
Abstract
The majority of phages, viruses that infect prokaryotes, inject their genomic material into their host through a tubular assembly known as a tail. Despite the genomic diversity of tailed phages, only three morphological archetypes have been described: contractile tails of Myoviridae-like phages; short non-contractile tails of Podoviridae-like phages; and long and flexible non-contractile tails of Siphoviridae-like phages. While early cryo-electron microscopy (cryo-EM) work elucidated the organisation of the syringe-like injection mechanism of contractile tails, the intrinsic flexibility of the long non-contractile tails prevented high-resolution structural determination. In 2020, four cryo-EM structures of Siphoviridae-like tail tubes were solved and revealed common themes and divergences. The central tube is structurally conserved and homologous to the hexameric rings of the tail tube protein (TTP) also found in contractile tails, bacterial pyocins, and type VI secretion systems. The interior surface of the tube presents analogous motifs of negatively charged amino acids proposed to facilitate ratcheting of the DNA during genome ejection. The lack of a conformational change upon genome ejection implicates the tape measure protein in triggering genome release. A distinctive feature of Siphoviridae-like tails is their flexibility. This results from loose inter-ring connections that can asymmetrically stretch on one side to allow bending and flexing of the tube without breaking. The outer surface of the tube differs greatly and may be smooth or rugged due to additional Ig-like domains in TTP. Some of these variable domains may contribute to adsorption of the phage to prokaryotic and eukaryotic cell surfaces affecting tropism and virulence.
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Abstract
Pyocins are phage tail-like protein complexes that can be used by Pseudomonas aeruginosa to enact intraspecies competition by killing competing strains. The pyocin gene cluster also encodes holin and lysin enzymes that lyse producer cells to release the pyocins. The best-known inducers of pyocin production under laboratory conditions are DNA-damaging agents, including fluoroquinolone antibiotics, that activate the SOS response. Here, we report the discovery of an alternate, RecA-independent pathway of strong pyocin induction that is active in cells deficient for the tyrosine recombinase XerC. When ΔxerC cells were examined at the single-cell level, only a fraction of the cell population strongly expressed pyocins before explosively lysing, suggesting a that a built-in heterogenous response system protects the cell population from widespread lysis. Disabling the holin and lysin enzymes or deleting the entire pyocin gene cluster blocked explosive lysis and delayed but did not prevent the death of pyocin-producing cells, suggesting that ΔxerC cells activate other lysis pathways. Mutating XerC to abolish its recombinase activity induced pyocin expression to a lesser extent than the full deletion, suggesting that XerC has multiple functions with respect to pyocin activation. Our studies uncover a new pathway for pyocin production and highlight its response across a genetically identical population. Moreover, our finding that ΔxerC populations are hypersensitive to fluoroquinolones raises the intriguing possibility that XerC inhibition may potentiate the activity of these antibiotics against P. aeruginosa infections. IMPORTANCE Pseudomonas aeruginosa is a versatile and ubiquitous bacterium that frequently infects humans as an opportunistic pathogen. P. aeruginosa competes with other strains within the species by producing killing complexes termed pyocins, which are only known to be induced by cells experiencing DNA damage and the subsequent SOS response. Here, we discovered that strains lacking a recombinase enzyme called XerC strongly produce pyocins independently of the SOS response. We also show that these strains are hypersensitive to commonly used fluoroquinolone antibiotic treatment and that fluoroquinolones further stimulate pyocin production. Thus, XerC is an attractive target for future therapies that simultaneously sensitize P. aeruginosa to antibiotics and stimulate the production of bactericidal pyocins.
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Major tail proteins of bacteriophages of the order Caudovirales. J Biol Chem 2021; 298:101472. [PMID: 34890646 PMCID: PMC8718954 DOI: 10.1016/j.jbc.2021.101472] [Citation(s) in RCA: 28] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/28/2021] [Revised: 11/15/2021] [Accepted: 11/16/2021] [Indexed: 12/18/2022] Open
Abstract
Technological advances in cryo-EM in recent years have given rise to detailed atomic structures of bacteriophage tail tubes-a class of filamentous protein assemblies that could previously only be studied on the atomic scale in either their monomeric form or when packed within a crystal lattice. These hollow elongated protein structures, present in most bacteriophages of the order Caudovirales, connect the DNA-containing capsid with a receptor function at the distal end of the tail and consist of helical and polymerized major tail proteins. However, the resolution of cryo-EM data for these systems differs enormously between different tail tube types, partly inhibiting the building of high-fidelity models and barring a combination with further structural biology methods. Here, we review the structural biology efforts within this field and highlight the role of integrative structural biology approaches that have proved successful for some of these systems. Finally, we summarize the structural elements of major tail proteins and conceptualize how different amounts of tail tube flexibility confer heterogeneity within cryo-EM maps and, thus, limit high-resolution reconstructions.
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Aruwa CE, Pillay C, Nyaga MM, Sabiu S. Poultry gut health - microbiome functions, environmental impacts, microbiome engineering and advancements in characterization technologies. J Anim Sci Biotechnol 2021; 12:119. [PMID: 34857055 PMCID: PMC8638651 DOI: 10.1186/s40104-021-00640-9] [Citation(s) in RCA: 33] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/01/2021] [Accepted: 10/01/2021] [Indexed: 12/12/2022] Open
Abstract
The gastrointestinal tract (GIT) health impacts animal productivity. The poultry microbiome has functions which range from protection against pathogens and nutrients production, to host immune system maturation. Fluctuations in the microbiome have also been linked to prevailing environmental conditions. Healthy poultry birds possess a natural resistance to infection. However, the exploration of environmental impacts and other relevant factors on poultry growth and health have been underplayed. Since good performance and growth rate are central to animal production, the host-microbiome relationship remains integral. Prior to the emergence of metagenomic techniques, conventional methods for poultry microbiome studies were used and were low-throughput and associated with insufficient genomic data and high cost of sequencing. Fortunately, the advent of high-throughput sequencing platforms have circumvented some of these shortfalls and paved the way for increased studies on the poultry gut microbiome diversity and functions. Here, we give an up-to-date review on the impact of varied environments on microbiome profile, as well as microbiome engineering and microbiome technology advancements. It is hoped that this paper will provide invaluable information that could guide and inspire further studies on the lingering pertinent questions about the poultry microbiome.
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Affiliation(s)
- Christiana Eleojo Aruwa
- Department of Biotechnology and Food Science, Faculty of Applied Sciences, Durban University of Technology, P.O. Box 1334, Durban, 4000, South Africa
| | - Charlene Pillay
- Department of Biotechnology and Food Science, Faculty of Applied Sciences, Durban University of Technology, P.O. Box 1334, Durban, 4000, South Africa
| | - Martin M Nyaga
- Next Generation Sequencing Unit, Division of Virology, Faculty of Heath Sciences, University of the Free State, Bloemfontein, South Africa
| | - Saheed Sabiu
- Department of Biotechnology and Food Science, Faculty of Applied Sciences, Durban University of Technology, P.O. Box 1334, Durban, 4000, South Africa.
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Inhibiting Type VI Secretion System Activity with a Biomimetic Peptide Designed To Target the Baseplate Wedge Complex. mBio 2021; 12:e0134821. [PMID: 34372705 PMCID: PMC8406304 DOI: 10.1128/mbio.01348-21] [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] [Indexed: 12/26/2022] Open
Abstract
Human health is threatened by bacterial infections that are increasingly resistant to multiple drugs. A recently emerged strategy consists of disarming pathogenic bacteria by targeting and blocking their virulence factors. The type VI secretion system (T6SS) is a widespread secretion nanomachine encoded and employed by pathogenic strains to establish their virulence process during host invasion. Given the conservation of T6SS in several human bacterial pathogens, the discovery of an effective broad-spectrum T6SS virulence blocker represents an attractive target for development of antivirulence therapies. Here, we identified and validated a protein-protein interaction interface, TssK-TssG, as a key factor in the assembly of the T6SS baseplate (BP) complex in the pathogen enteroaggregative Escherichia coli (EAEC). In silico and biochemical studies revealed that the determinants of the interface are broadly conserved among pathogenic species, suggesting a role for this interface as a target for T6SS inhibition. Based on the high-resolution structure of the TssKFGE wedge complex, we rationally designed a biomimetic cyclic peptide (BCP) that blocks the assembly of the EAEC BP complex and inhibits the function of T6SS in bacterial cultures. Our BCP is the first compound completely designed from prior structural knowledge with anti-T6SS activity that can be used as a model to target human pathogens.
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30
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Peterson SB, Bertolli SK, Mougous JD. The Central Role of Interbacterial Antagonism in Bacterial Life. Curr Biol 2021; 30:R1203-R1214. [PMID: 33022265 DOI: 10.1016/j.cub.2020.06.103] [Citation(s) in RCA: 49] [Impact Index Per Article: 16.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
The study of bacteria interacting with their environment has historically centered on strategies for obtaining nutrients and resisting abiotic stresses. We argue this focus has deemphasized a third facet of bacterial life that is equally central to their existence: namely, the threat to survival posed by antagonizing bacteria. The diversity and ubiquity of interbacterial antagonism pathways is becoming increasingly apparent, and the insidious manner by which interbacterial toxins disarm their targets emphasizes the highly evolved nature of these processes. Studies examining the role of antagonism in natural communities reveal it can serve many functions, from facilitating colonization of naïve habitats to maintaining bacterial community stability. The pervasiveness of antagonistic pathways is necessarily matched by an equally extensive array of defense strategies. These overlap with well characterized, central stress response pathways, highlighting the contribution of bacterial interactions to shaping cell physiology. In this review, we build the case for the ubiquity and importance of interbacterial antagonism.
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Affiliation(s)
- S Brook Peterson
- Department of Microbiology, University of Washington School of Medicine, Seattle, WA 98195, USA
| | - Savannah K Bertolli
- Department of Microbiology, University of Washington School of Medicine, Seattle, WA 98195, USA; Howard Hughes Medical Institute, University of Washington, Seattle, WA 98195, USA
| | - Joseph D Mougous
- Department of Microbiology, University of Washington School of Medicine, Seattle, WA 98195, USA; Howard Hughes Medical Institute, University of Washington, Seattle, WA 98195, USA; Department of Biochemistry, University of Washington School of Medicine, Seattle, WA 98195, USA.
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31
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Cai X, Liu L, Qiu C, Wen C, He Y, Cui Y, Li S, Zhang X, Zhang L, Tian C, Bi L, Zhou ZH, Gong W. Identification and architecture of a putative secretion tube across mycobacterial outer envelope. SCIENCE ADVANCES 2021; 7:7/34/eabg5656. [PMID: 34417177 PMCID: PMC8378821 DOI: 10.1126/sciadv.abg5656] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 01/16/2021] [Accepted: 06/29/2021] [Indexed: 06/13/2023]
Abstract
Tuberculosis-causing mycobacteria have thick cell-wall and capsule layers that are formed from complex structures. Protein secretion across these barriers depends on a specialized protein secretion system, but none has been reported. We show that Mycobacterium tuberculosis Rv3705c and its homologous MSMEG_6251 in Mycobacterium smegmatis are tube-forming proteins in the mycobacterial envelope (TiME). Crystallographic and cryo-EM structures of these two proteins show that both proteins form rotationally symmetric rings. Two layers of TiME rings pack together in a tail-to-tail manner into a ring-shaped complex, which, in turn, stacks together to form tubes. M. smegmatis TiME was detected mainly in the cell wall and capsule. Knocking out the TiME gene markedly decreased the amount of secreted protein in the M. smegmatis culture medium, and expression of this gene in knocked-out strain partially restored the level of secreted protein. Our structure and functional data thus suggest that TiME forms a protein transport tube across the mycobacterial outer envelope.
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Affiliation(s)
- Xiaoying Cai
- School of Life Sciences, University of Science and Technology of China, Hefei, Anhui, China
| | - Lei Liu
- Hefei National Laboratory for Physical Sciences at the Microscale, University of Science and Technology of China, Hefei, Anhui, China
| | - Chunhong Qiu
- School of Life Sciences, University of Science and Technology of China, Hefei, Anhui, China
| | - Chongzheng Wen
- Hefei National Laboratory for Physical Sciences at the Microscale, University of Science and Technology of China, Hefei, Anhui, China
| | - Yao He
- California NanoSystems Institute, University of California, Los Angeles (UCLA), Los Angeles, CA 90095, USA
- Department of Microbiology, Immunology and Molecular Genetics, UCLA, Los Angeles, CA 90095, USA
| | - Yanxiang Cui
- California NanoSystems Institute, University of California, Los Angeles (UCLA), Los Angeles, CA 90095, USA
| | - Siyu Li
- School of Life Sciences, University of Science and Technology of China, Hefei, Anhui, China
| | - Xuan Zhang
- Institute of Health Science, Institutes of Physical Science and Information Technology, Anhui University, Hefei, Anhui, China
| | - Longhua Zhang
- School of Life Sciences, University of Science and Technology of China, Hefei, Anhui, China
| | - Changlin Tian
- School of Life Sciences, University of Science and Technology of China, Hefei, Anhui, China
| | - Lijun Bi
- Institute of Biophysics, Chinese Academy of Sciences, Beijing, China
| | - Z Hong Zhou
- California NanoSystems Institute, University of California, Los Angeles (UCLA), Los Angeles, CA 90095, USA.
- Department of Microbiology, Immunology and Molecular Genetics, UCLA, Los Angeles, CA 90095, USA
| | - Weimin Gong
- School of Life Sciences, University of Science and Technology of China, Hefei, Anhui, China.
- Hefei National Laboratory for Physical Sciences at the Microscale, University of Science and Technology of China, Hefei, Anhui, China
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Fraser A, Prokhorov NS, Jiao F, Pettitt BM, Scheuring S, Leiman PG. Quantitative description of a contractile macromolecular machine. SCIENCE ADVANCES 2021; 7:7/24/eabf9601. [PMID: 34117062 PMCID: PMC8195476 DOI: 10.1126/sciadv.abf9601] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/01/2020] [Accepted: 04/23/2021] [Indexed: 05/14/2023]
Abstract
Contractile injection systems (CISs) [type VI secretion system (T6SS), phage tails, and tailocins] use a contractile sheath-rigid tube machinery to breach cell walls and lipid membranes. The structures of the pre- and postcontraction states of several CISs are known, but the mechanism of contraction remains poorly understood. Combining structural information of the end states of the 12-megadalton R-type pyocin sheath-tube complex with thermodynamic and force spectroscopy analyses and an original modeling procedure, we describe the mechanism of pyocin contraction. We show that this nanomachine has an activation energy of 160 kilocalories/mole (kcal/mol), and it releases 2160 kcal/mol of heat and develops a force greater than 500 piconewtons. Our combined approach provides a quantitative and experimental description of the membrane penetration process by a CIS.
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Affiliation(s)
- Alec Fraser
- Department of Biochemistry and Molecular Biology, Sealy Center for Structural Biology and Molecular Biophysics (SCSB), The University of Texas Medical Branch at Galveston, Galveston, TX 77555, USA
| | - Nikolai S Prokhorov
- Department of Biochemistry and Molecular Biology, Sealy Center for Structural Biology and Molecular Biophysics (SCSB), The University of Texas Medical Branch at Galveston, Galveston, TX 77555, USA
| | - Fang Jiao
- Department of Anesthesiology, Weill Cornell Medicine, 1300 York Avenue, New York, NY 10065, USA
- Department of Physiology and Biophysics, Weill Cornell Medicine, 1300 York Avenue, New York, NY 10065, USA
| | - B Montgomery Pettitt
- Department of Biochemistry and Molecular Biology, Sealy Center for Structural Biology and Molecular Biophysics (SCSB), The University of Texas Medical Branch at Galveston, Galveston, TX 77555, USA
| | - Simon Scheuring
- Department of Anesthesiology, Weill Cornell Medicine, 1300 York Avenue, New York, NY 10065, USA.
- Department of Physiology and Biophysics, Weill Cornell Medicine, 1300 York Avenue, New York, NY 10065, USA
| | - Petr G Leiman
- Department of Biochemistry and Molecular Biology, Sealy Center for Structural Biology and Molecular Biophysics (SCSB), The University of Texas Medical Branch at Galveston, Galveston, TX 77555, USA.
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Heterogenous Susceptibility to R-Pyocins in Populations of Pseudomonas aeruginosa Sourced from Cystic Fibrosis Lungs. mBio 2021; 12:mBio.00458-21. [PMID: 33947755 PMCID: PMC8262887 DOI: 10.1128/mbio.00458-21] [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] [Indexed: 12/17/2022] Open
Abstract
Bacteriocins are proteinaceous antimicrobials produced by bacteria that are active against other strains of the same species. R-type pyocins are phage tail-like bacteriocins produced by Pseudomonas aeruginosa Due to their antipseudomonal activity, R-pyocins have potential as therapeutics in infection. P. aeruginosa is a Gram-negative opportunistic pathogen and is particularly problematic for individuals with cystic fibrosis (CF). P. aeruginosa organisms from CF lung infections develop increasing resistance to antibiotics, making new treatment approaches essential. P. aeruginosa populations become phenotypically and genotypically diverse during infection; however, little is known of the efficacy of R-pyocins against heterogeneous populations. R-pyocins vary by subtype (R1 to R5), distinguished by binding to different residues on the lipopolysaccharide (LPS). Each type varies in killing spectrum, and each strain produces only one R-type. To evaluate the prevalence of different R-types, we screened P. aeruginosa strains from the International Pseudomonas Consortium Database (IPCD) and from our biobank of CF strains. We found that (i) R1-types were the most prevalent R-type among strains from respiratory sources, (ii) a large number of strains lack R-pyocin genes, and (iii) isolates collected from the same patient have the same R-type. We then assessed the impact of intrastrain diversity on R-pyocin susceptibility and found a heterogenous response to R-pyocins within populations, likely due to differences in the LPS core. Our work reveals that heterogeneous populations of microbes exhibit variable susceptibility to R-pyocins and highlights that there is likely heterogeneity in response to other types of LPS-binding antimicrobials, including phage.IMPORTANCE R-pyocins have potential as alternative therapeutics against Pseudomonas aeruginosa in chronic infection; however, little is known about the efficacy of R-pyocins in heterogeneous bacterial populations. P. aeruginosa is known to become resistant to multiple antibiotics and to evolve phenotypic and genotypic diversity over time; thus, it is particularly difficult to eradicate in chronic cystic fibrosis (CF) lung infections. In this study, we found that P. aeruginosa populations from CF lungs maintain the same R-pyocin genotype but exhibit heterogeneity in susceptibility to R-pyocins from other strains. Our findings suggest there is heterogeneity in response to other types of LPS-binding antimicrobials, such as phage, highlighting the necessity of further studying the potential of LPS-binding antimicrobial particles as alternative therapies in chronic infections.
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Patel RR, Kandel PP, Traverso E, Hockett KL, Triplett LR. Pseudomonas syringae pv. phaseolicola Uses Distinct Modes of Stationary-Phase Persistence To Survive Bacteriocin and Streptomycin Treatments. mBio 2021; 12:e00161-21. [PMID: 33849974 PMCID: PMC8092213 DOI: 10.1128/mbio.00161-21] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/19/2021] [Accepted: 03/11/2021] [Indexed: 02/08/2023] Open
Abstract
Antimicrobial treatment of bacteria often results in a small population of surviving tolerant cells, or persisters, that may contribute to recurrent infection. Antibiotic persisters are metabolically dormant, but the basis of their persistence in the presence of membrane-disrupting biological compounds is less well understood. We previously found that the model plant pathogen Pseudomonas syringae pv. phaseolicola 1448A (Pph) exhibits persistence to tailocin, a membrane-disrupting biocontrol compound with potential for sustainable disease control. Here, we compared physiological traits associated with persistence to tailocin and to the antibiotic streptomycin and established that both treatments leave similar frequencies of persisters. Microscopic profiling of treated populations revealed that while tailocin rapidly permeabilizes most cells, streptomycin treatment results in a heterogeneous population in the redox and membrane permeability state. Intact cells were sorted into three fractions according to metabolic activity, as indicated by a redox-sensing reporter dye. Streptomycin persisters were cultured from the fraction associated with the lowest metabolic activity, but tailocin persisters were cultured from a fraction associated with an active metabolic signal. Cells from culturable fractions were able to infect host plants, while the nonculturable fractions were not. Tailocin and streptomycin were effective in eliminating all persisters when applied sequentially, in addition to eliminating cells in other viable states. This study identifies distinct metabolic states associated with antibiotic persistence, tailocin persistence, and loss of virulence and demonstrates that tailocin is highly effective in eliminating dormant cells.IMPORTANCE Populations of genetically identical bacteria encompass heterogeneous physiological states. The small fraction of bacteria that are dormant can help the population survive exposure to antibiotics and other stresses, potentially contributing to recurring infection cycles in animal or plant hosts. Membrane-disrupting biological control treatments are effective in killing dormant bacteria, but these treatments also leave persister-like survivors. The current work demonstrates that in Pph, persisters surviving treatment with membrane-disrupting tailocin proteins have an elevated redox state compared to that of dormant streptomycin persisters. Combination treatment was effective in killing both persister types. Culturable persisters corresponded closely with infectious cells in each treated population, whereas the high-redox and unculturable fractions were not infectious. In linking redox states to heterogeneous phenotypes of tailocin persistence, streptomycin persistence, and infection capability, this work will inform the search for mechanisms and markers for each phenotype.
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Affiliation(s)
- Ravikumar R Patel
- Department of Plant Pathology and Ecology, The Connecticut Agricultural Experiment Station, New Haven, Connecticut, USA
| | - Prem P Kandel
- Department of Plant Pathology and Environmental Microbiology, The Pennsylvania State University, University Park, Pennsylvania, USA
| | - Eboni Traverso
- Department of Plant Pathology and Ecology, The Connecticut Agricultural Experiment Station, New Haven, Connecticut, USA
| | - Kevin L Hockett
- Department of Plant Pathology and Environmental Microbiology, The Pennsylvania State University, University Park, Pennsylvania, USA
- Center for Infectious Disease Dynamics, Pennsylvania State University, University Park, Pennsylvania, USA
- Huck Institutes for the Life Sciences, Pennsylvania State University, University Park, Pennsylvania, USA
| | - Lindsay R Triplett
- Department of Plant Pathology and Ecology, The Connecticut Agricultural Experiment Station, New Haven, Connecticut, USA
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35
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Dunne M, Prokhorov NS, Loessner MJ, Leiman PG. Reprogramming bacteriophage host range: design principles and strategies for engineering receptor binding proteins. Curr Opin Biotechnol 2021; 68:272-281. [PMID: 33744824 PMCID: PMC10163921 DOI: 10.1016/j.copbio.2021.02.006] [Citation(s) in RCA: 40] [Impact Index Per Article: 13.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/24/2020] [Revised: 02/09/2021] [Accepted: 02/19/2021] [Indexed: 01/09/2023]
Abstract
Bacteriophages (phages) use specialized tail machinery to deliver proteins and genetic material into a bacterial cell during infection. Attached at the distal ends of their tails are receptor binding proteins (RBPs) that recognize specific molecules exposed on host bacteria surfaces. Since the therapeutic capacity of naturally occurring phages is often limited by narrow host ranges, there is significant interest in expanding their host range via directed evolution or structure-guided engineering of their RBPs. Here, we describe the design principles of different RBP engineering platforms and draw attention to the mechanisms linking RBP binding and the correct spatial and temporal attachment of the phage to the bacterial surface. A deeper understanding of these mechanisms will directly benefit future engineering of more effective phage-based therapeutics.
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Affiliation(s)
- Matthew Dunne
- Institute of Food, Nutrition and Health, ETH Zurich, Schmelzbergstrasse 7, 8092, Zurich, Switzerland.
| | - Nikolai S Prokhorov
- Department of Biochemistry and Molecular Biology, Sealy Center for Structural Biology and Molecular Biophysics, University of Texas Medical Branch, 301 University Boulevard, Galveston, TX, USA
| | - Martin J Loessner
- Institute of Food, Nutrition and Health, ETH Zurich, Schmelzbergstrasse 7, 8092, Zurich, Switzerland
| | - Petr G Leiman
- Department of Biochemistry and Molecular Biology, Sealy Center for Structural Biology and Molecular Biophysics, University of Texas Medical Branch, 301 University Boulevard, Galveston, TX, USA
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36
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Vacheron J, Heiman CM, Keel C. Live cell dynamics of production, explosive release and killing activity of phage tail-like weapons for Pseudomonas kin exclusion. Commun Biol 2021; 4:87. [PMID: 33469108 PMCID: PMC7815802 DOI: 10.1038/s42003-020-01581-1] [Citation(s) in RCA: 23] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/06/2020] [Accepted: 12/07/2020] [Indexed: 01/29/2023] Open
Abstract
Interference competition among bacteria requires a highly specialized, narrow-spectrum weaponry when targeting closely-related competitors while sparing individuals from the same clonal population. Here we investigated mechanisms by which environmentally important Pseudomonas bacteria with plant-beneficial activity perform kin interference competition. We show that killing between phylogenetically closely-related strains involves contractile phage tail-like devices called R-tailocins that puncture target cell membranes. Using live-cell imaging, we evidence that R-tailocins are produced at the cell center, transported to the cell poles and ejected by explosive cell lysis. This enables their dispersal over several tens of micrometers to reach targeted cells. We visualize R-tailocin-mediated competition dynamics between closely-related Pseudomonas strains at the single-cell level, both in non-induced condition and upon artificial induction. We document the fatal impact of cellular self-sacrifice coupled to deployment of phage tail-like weaponry in the microenvironment of kin bacterial competitors, emphasizing the necessity for microscale assessment of microbial competitions.
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Affiliation(s)
- Jordan Vacheron
- Department of Fundamental Microbiology, University of Lausanne, CH-1015, Lausanne, Switzerland.
| | - Clara Margot Heiman
- Department of Fundamental Microbiology, University of Lausanne, CH-1015, Lausanne, Switzerland
| | - Christoph Keel
- Department of Fundamental Microbiology, University of Lausanne, CH-1015, Lausanne, Switzerland.
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37
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Tridgett M, Ababi M, Osgerby A, Ramirez Garcia R, Jaramillo A. Engineering Bacteria to Produce Pure Phage-like Particles for Gene Delivery. ACS Synth Biol 2021; 10:107-114. [PMID: 33317264 DOI: 10.1021/acssynbio.0c00467] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/21/2023]
Abstract
Natural and engineered phages have been used in many applications, but their use to deliver user-defined genetic cargoes has been hampered by contamination with replicative phage, restricting use of the technology beyond the laboratory. Here we present a method to produce transducing particles without contamination. In addition, we demonstrate the use of a helper phage-free transducing particle preparation as an antimicrobial agent. This will pave the way for the development of new phage-based technologies with greater scope than lytic phage therapy.
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Affiliation(s)
- Matthew Tridgett
- School of Life Sciences, Gibbet Hill Campus, The University of Warwick, Coventry, CV4 7AL, U.K
| | - Maria Ababi
- School of Life Sciences, Gibbet Hill Campus, The University of Warwick, Coventry, CV4 7AL, U.K
- Warwick Medical School, University of Warwick, Coventry, CV4 7AL, U.K
| | - Alexander Osgerby
- School of Life Sciences, Gibbet Hill Campus, The University of Warwick, Coventry, CV4 7AL, U.K
| | - Robert Ramirez Garcia
- School of Life Sciences, Gibbet Hill Campus, The University of Warwick, Coventry, CV4 7AL, U.K
| | - Alfonso Jaramillo
- School of Life Sciences, Gibbet Hill Campus, The University of Warwick, Coventry, CV4 7AL, U.K
- CNRS, Paris, 75016, France
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38
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Computational image analysis of the baseplate-tail complex of O1 ElTor vibriophage M4. Arch Virol 2020; 165:2641-2646. [DOI: 10.1007/s00705-020-04765-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/29/2020] [Accepted: 07/02/2020] [Indexed: 10/23/2022]
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39
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Snopkova K, Dufkova K, Klimesova P, Vanerkova M, Ruzicka F, Hola V. Prevalence of bacteriocins and their co-association with virulence factors within Pseudomonas aeruginosa catheter isolates. Int J Med Microbiol 2020; 310:151454. [PMID: 33068882 DOI: 10.1016/j.ijmm.2020.151454] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/14/2020] [Revised: 09/09/2020] [Accepted: 09/27/2020] [Indexed: 11/29/2022] Open
Abstract
Urinary tract infections represent common nosocomial infectious diseases. Bacteriocin production has been recently described as a putative virulence factor in these infections but studies focusing particularly on Pseudomonas aeruginosa are not available. Therefore, we assessed the prevalence of the bacteriocin genes, their co-occurrence and their co-association with previously detected virulence factors in a set of 135 P. aeruginosa strains from catheter-associated urinary tract infections (CAUTIs). The overall bacteriocinogeny reached 96.3 % with an average of 3.6 genes per strain. The most frequently detected determinants were the encoded pyocins S4 (76.3 %), R (69.6 %), and S2 (67.4 %). A statistically significant co-occurrence and a negative relationship were observed between several pyocin types. Particular pyocins exhibited associations with biofilm formation, production of pyochelin, pyocyanin, antibiotic-degrading enzymes, overall strain susceptibility and resistance, and motility of the strain. Co-occurrence of the pyocins S2 and S4 (p<<0.0001; Z = 13.15), both utilizating the ferripyoverdine receptor FpvAI, was found but no relation to pyoverdine production was detected. A negative association (p = 0.0047; Z=-2.83) was observed between pyochelin and pyocin S5 utilising the ferripyochelin receptor FptA. Pairwise assays resulted in 52.1 % inhibition which was equally distributed between soluble and particle types of antimicrobials. In conclusion, pyocin determinants appear to be important characteristics of CAUTI-related P. aeruginosa isolates and could contribute to their urovirulence.
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Affiliation(s)
- Katerina Snopkova
- Institute for Microbiology, Faculty of Medicine, Masaryk University and St. Anne's University Hospital Brno, Pekarska 53, 656 91 Brno, Czech Republic
| | - Kristyna Dufkova
- Institute for Microbiology, Faculty of Medicine, Masaryk University and St. Anne's University Hospital Brno, Pekarska 53, 656 91 Brno, Czech Republic
| | - Petra Klimesova
- Institute for Microbiology, Faculty of Medicine, Masaryk University and St. Anne's University Hospital Brno, Pekarska 53, 656 91 Brno, Czech Republic
| | - Martina Vanerkova
- Molecular and Genetics Laboratory, Centre for Cardiovascular Surgery and Transplantation, Pekarska 53, 656 91 Brno, Czech Republic
| | - Filip Ruzicka
- Institute for Microbiology, Faculty of Medicine, Masaryk University and St. Anne's University Hospital Brno, Pekarska 53, 656 91 Brno, Czech Republic
| | - Veronika Hola
- Institute for Microbiology, Faculty of Medicine, Masaryk University and St. Anne's University Hospital Brno, Pekarska 53, 656 91 Brno, Czech Republic.
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40
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Abstract
R-type bacteriocins are minimal contractile nanomachines that hold promise as precision antibiotics1–4. Each bactericidal complex uses a collar to bridge a hollow tube with a contractile sheath loaded in a metastable state by a baseplate scaffold1,2. Fine-tuning of such nucleic acid-free protein machines for precision medicine calls for an atomic description of the entire complex and contraction mechanism, which is not available from baseplate structures of (DNA-containing) T4 bacteriophage5. Here we report the atomic model of the complete R2 pyocin in its pre- and post-contraction states, each containing 384 subunits of 11 unique atomic models of 10 gene products. Comparison of these structures suggests the sequence of events during pyocin contraction: tail fibers trigger lateral dissociation of baseplate triplexes; the dissociation then initiates a cascade of events leading to sheath contraction; this contraction converts chemical energy into mechanical force to drive the iron-tipped tube across the bacterial cell surface, killing the bacterium.
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41
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Double Tubular Contractile Structure of the Type VI Secretion System Displays Striking Flexibility and Elasticity. J Bacteriol 2019; 202:JB.00425-19. [PMID: 31636107 DOI: 10.1128/jb.00425-19] [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: 06/21/2019] [Accepted: 10/14/2019] [Indexed: 12/22/2022] Open
Abstract
Antimicrobial treatment can induce many bacterial pathogens to enter a cell wall-deficient state that contributes to persistent infections. The effect of this physiological state on the assembly of transenvelope-anchored organelles is not well understood. The type VI secretion system (T6SS) is a widespread molecular weapon for interspecies interactions and virulence, comprising a long double tubular structure and a transenvelope/baseplate complex. Here, we report that cell wall-deficient spheroplasts assembled highly flexible and elastic T6SS structures forming U, O, or S shapes. Upon contacting the inner membrane, the T6SS tubes did not contract but rather continued to grow along the membrane. Such deformation likely results from continual addition of sheath/tube subunits at the distal end. Induction of TagA repressed curved sheath formation. Curved sheaths could also contract and deliver T6SS substrates and were readily disassembled by the ClpV ATPase after contraction. Our data highlight the dramatic effect of cell wall deficiency on the shape of the T6SS structures and reveal the elastic nature of this double tubular contractile injection nanomachine.IMPORTANCE The cell wall is a physical scaffold that all transenvelope complexes have to cross for assembly. However, the cell wall-deficient state has been described as a common condition found in both Gram-negative and Gram-positive pathogens during persistent infections. Loss of cell wall is known to have pleiotropic physiological effects, but how membrane-anchored large cellular organelles adapt to this unique state is less completely understood. Our study examined the assembly of the T6SS in cell wall-deficient spheroplast cells. We report the elastic nature of contractile T6SS tubules under such conditions, providing key insights for understanding how large intracellular structures such as the T6SS accommodate the multifaceted changes in cell wall-deficient cells.
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42
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How the phage T4 injection machinery works including energetics, forces, and dynamic pathway. Proc Natl Acad Sci U S A 2019; 116:25097-25105. [PMID: 31767752 DOI: 10.1073/pnas.1909298116] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
The virus bacteriophage T4, from the family Myoviridae, employs an intriguing contractile injection machine to inject its genome into the bacterium Escherichia coli Although the atomic structure of phage T4 is largely understood, the dynamics of its injection machinery remains unknown. This study contributes a system-level model describing the nonlinear dynamics of the phage T4 injection machinery interacting with a host cell. The model employs a continuum representation of the contractile sheath using elastic constants inferred from atomistic molecular-dynamics (MD) simulations. Importantly, the sheath model is coupled to component models representing the remaining structures of the virus and the host cell. The resulting system-level model captures virus-cell interactions as well as competing energetic mechanisms that release and dissipate energy during the injection process. Simulations reveal the dynamical pathway of the injection process as a "contraction wave" that propagates along the sheath, the energy that powers the injection machinery, the forces responsible for piercing the host cell membrane, and the energy dissipation that controls the timescale of the injection process. These results from the model compare favorably with the available (but limited) experimental measurements.
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43
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Chatterjee A, Maghsoodi A, Perkins NC, Andricioaei I. Elastic continuum stiffness of contractile tail sheaths from molecular dynamics simulations. J Chem Phys 2019; 151:185103. [PMID: 31731851 DOI: 10.1063/1.5125807] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
Contractile tails are key components of the biological nanomachinery involved in cell membrane puncturing, where they provide a means to deliver molecules and ions inside cells. Two intriguing examples of contractile tails are those from bacteriophage T4 and R2-pyocin. Although the two systems are different in terms of biological activity, they share a fascinatingly similar injection mechanism, during which the tail sheaths of both systems contract from a so-called extended state to around half of their length (the contracted state), accompanied by release of elastic energy originally stored in the sheath. Despite the great prevalence and biomedical importance of contractile delivery systems, many fundamental details of their injection machinery and dynamics are still unknown. In this work, we calculate the bending and torsional stiffness constants of a helical tail sheath strand of bacteriophage T4 and R2-pyocin, in both extended and contracted states, using molecular dynamics simulations of about one-sixth of the entire sheath. Differences in stiffness constants between the two systems are rationalized by comparing their all-atom monomer structures, changes in sheath architecture on contraction, and differences in interstrand interactions. The calculated coefficients indicate that the T4 strand is stiffer for both bending and torsion than the corresponding R2-pyocin strands in both extended and contracted conformations. The sheath strands also have greater stiffness in the contracted state for both systems. As the main application of this study, we describe how the stiffness constants can be incorporated in a model to simulate the dynamics of contractile nanoinjection machineries.
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Affiliation(s)
- A Chatterjee
- Department of Chemistry, University of California, Irvine, California 92697, USA
| | - A Maghsoodi
- Department of Mechanical Engineering, University of Michigan, Ann Arbor, Michigan 48109, USA
| | - N C Perkins
- Department of Mechanical Engineering, University of Michigan, Ann Arbor, Michigan 48109, USA
| | - I Andricioaei
- Department of Chemistry, University of California, Irvine, California 92697, USA
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44
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Campbell PL, Duda RL, Nassur J, Conway JF, Huet A. Mobile Loops and Electrostatic Interactions Maintain the Flexible Tail Tube of Bacteriophage Lambda. J Mol Biol 2019; 432:384-395. [PMID: 31711962 DOI: 10.1016/j.jmb.2019.10.031] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/25/2019] [Revised: 10/26/2019] [Accepted: 10/31/2019] [Indexed: 12/11/2022]
Abstract
The long flexible tail tube of bacteriophage lambda connects its capsid to the tail tip. On infection, a DNA ejection signal is passed from the tip, along the tube to the capsid that triggers passage of the DNA down the tube and into the host bacterium. The tail tube is built from repeating units of the major tail protein, gpV, which has two distinctive domains. Its N-terminal domain has the same fold as proteins that form the rigid inner tubes of contractile tail phages, such as T4, and its C-terminal domain adopt an Ig-like fold of unknown function. We determined structures of the lambda tail tube in free tails and in virions before and after DNA ejection using cryoelectron microscopy. Modeling of the density maps reveals how electrostatic interactions and a mobile loop participate in assembly and also impart flexibility to the tube while maintaining its integrity. We also demonstrate how a common protein fold produces rigid tubes in some phages but flexible tubes in others.
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Affiliation(s)
- Patricia L Campbell
- Department of Biological Sciences, Dietrich School of Arts and Sciences, Pittsburgh, PA 15260, USA; Department of Structural Biology, School of Medicine, University of Pittsburgh, Pittsburgh, PA 15260, USA
| | - Robert L Duda
- Department of Biological Sciences, Dietrich School of Arts and Sciences, Pittsburgh, PA 15260, USA
| | - Jamie Nassur
- Department of Structural Biology, School of Medicine, University of Pittsburgh, Pittsburgh, PA 15260, USA
| | - James F Conway
- Department of Structural Biology, School of Medicine, University of Pittsburgh, Pittsburgh, PA 15260, USA.
| | - Alexis Huet
- Department of Biological Sciences, Dietrich School of Arts and Sciences, Pittsburgh, PA 15260, USA; Department of Structural Biology, School of Medicine, University of Pittsburgh, Pittsburgh, PA 15260, USA
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45
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Vlisidou I, Hapeshi A, Healey JR, Smart K, Yang G, Waterfield NR. The Photorhabdus asymbiotica virulence cassettes deliver protein effectors directly into target eukaryotic cells. eLife 2019; 8:46259. [PMID: 31526474 PMCID: PMC6748792 DOI: 10.7554/elife.46259] [Citation(s) in RCA: 23] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/20/2019] [Accepted: 06/12/2019] [Indexed: 01/19/2023] Open
Abstract
Photorhabdus is a highly effective insect pathogen and symbiont of insecticidal nematodes. To exert its potent insecticidal effects, it elaborates a myriad of toxins and small molecule effectors. Among these, the Photorhabdus Virulence Cassettes (PVCs) represent an elegant self-contained delivery mechanism for diverse protein toxins. Importantly, these self-contained nanosyringes overcome host cell membrane barriers, and act independently, at a distance from the bacteria itself. In this study, we demonstrate that Pnf, a PVC needle complex associated toxin, is a Rho-GTPase, which acts via deamidation and transglutamination to disrupt the cytoskeleton. TEM and Western blots have shown a physical association between Pnf and its cognate PVC delivery mechanism. We demonstrate that for Pnf to exert its effect, translocation across the cell membrane is absolutely essential.
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Affiliation(s)
- Isabella Vlisidou
- All Wales Genetics Laboratory, Institute of Medical Genetics, University Hospital of Wales, Cardiff, United Kingdom
| | - Alexia Hapeshi
- Warwick Medical School, Warwick University, Coventry, United Kingdom
| | - Joseph Rj Healey
- Warwick Medical School, Warwick University, Coventry, United Kingdom
| | - Katie Smart
- Warwick Medical School, Warwick University, Coventry, United Kingdom
| | - Guowei Yang
- Beijing Friendship Hospital, Capital Medical University, Beijing, China
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46
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Lepore R, Kryshtafovych A, Alahuhta M, Veraszto HA, Bomble YJ, Bufton JC, Bullock AN, Caba C, Cao H, Davies OR, Desfosses A, Dunne M, Fidelis K, Goulding CW, Gurusaran M, Gutsche I, Harding CJ, Hartmann MD, Hayes CS, Joachimiak A, Leiman PG, Loppnau P, Lovering AL, Lunin VV, Michalska K, Mir-Sanchis I, Mitra AK, Moult J, Phillips GN, Pinkas DM, Rice PA, Tong Y, Topf M, Walton JD, Schwede T. Target highlights in CASP13: Experimental target structures through the eyes of their authors. Proteins 2019; 87:1037-1057. [PMID: 31442339 PMCID: PMC6851490 DOI: 10.1002/prot.25805] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/10/2019] [Revised: 08/09/2019] [Accepted: 08/19/2019] [Indexed: 01/10/2023]
Abstract
The functional and biological significance of selected CASP13 targets are described by the authors of the structures. The structural biologists discuss the most interesting structural features of the target proteins and assess whether these features were correctly reproduced in the predictions submitted to the CASP13 experiment.
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Affiliation(s)
- Rosalba Lepore
- BSC-CNS Barcelona Supercomputing Center, Barcelona, Spain
| | | | - Markus Alahuhta
- Biosciences Center, National Renewable Energy Laboratory, Golden, Colorado
| | - Harshul A Veraszto
- Department of Protein Evolution, Max Planck Institute for Developmental Biology, Tübingen, Germany
| | - Yannick J Bomble
- Biosciences Center, National Renewable Energy Laboratory, Golden, Colorado
| | - Joshua C Bufton
- Nuffield Department of Medicine; Structural Genomics Consortium, University of Oxford, Oxford, UK.,School of Biochemistry, University of Bristol, Bristol, UK
| | - Alex N Bullock
- Nuffield Department of Medicine; Structural Genomics Consortium, University of Oxford, Oxford, UK
| | - Cody Caba
- Department of Chemistry and Biochemistry, University of Windsor, Windsor, Ontario, Canada
| | - Hongnan Cao
- Department of BioSciences, Rice University, Houston, Texas.,Great Lakes Bioenergy Research Center, University of Wisconsin, Madison, Wisconsin
| | - Owen R Davies
- Institute for Cell and Molecular Biosciences, Faculty of Medical Sciences, Newcastle University, Newcastle upon Tyne, UK
| | - Ambroise Desfosses
- School of Biological Sciences, University of Auckland, Auckland, New Zealand.,Institut de Biologie Structurale, Université Grenoble Alpes, CEA, CNRS, Grenoble, France
| | - Matthew Dunne
- Institute of Food, Nutrition and Health, Zurich, Switzerland
| | | | - Celia W Goulding
- Department of Molecular Biology and Biochemistry; Pharmaceutical Sciences, University of California Irvine, Irvine, California
| | - Manickam Gurusaran
- Institute for Cell and Molecular Biosciences, Faculty of Medical Sciences, Newcastle University, Newcastle upon Tyne, UK
| | - Irina Gutsche
- Institut de Biologie Structurale, Université Grenoble Alpes, CEA, CNRS, Grenoble, France
| | | | - Marcus D Hartmann
- Department of Protein Evolution, Max Planck Institute for Developmental Biology, Tübingen, Germany
| | - Christopher S Hayes
- Department of Molecular, Cellular and Developmental Biology, Biomolecular Science and Engineering Program, University of California, Santa Barbara, California
| | - Andrzej Joachimiak
- Structural Biology Center, Biosciences Division, Midwest Center for Structural Genomics, Argonne.,Department of Biochemistry and Molecular Biology, University of Chicago, Chicago, Illinois
| | - Petr G Leiman
- Department of Biochemistry and Molecular Biology, Sealy Center for Structural Biology and Molecular Biophysics, University of Texas Medical Branch, Galveston, Texas
| | - Peter Loppnau
- Structural Genomics Consortium, University of Toronto, Toronto, Ontario, Canada
| | | | - Vladimir V Lunin
- Biosciences Center, National Renewable Energy Laboratory, Golden, Colorado
| | - Karolina Michalska
- Structural Biology Center, Biosciences Division, Midwest Center for Structural Genomics, Argonne
| | - Ignacio Mir-Sanchis
- Department of Biochemistry and Molecular Biology, The University of Chicago, Chicago, Illinois
| | - A K Mitra
- School of Biological Sciences, University of Auckland, Auckland, New Zealand
| | - John Moult
- Institute for Bioscience and Biotechnology Research, Department of Cell Biology and Molecular genetics, University of Maryland, Rockville, Maryland, USA
| | - George N Phillips
- Department of BioSciences, Rice University, Houston, Texas.,Great Lakes Bioenergy Research Center, University of Wisconsin, Madison, Wisconsin
| | - Daniel M Pinkas
- Nuffield Department of Medicine; Structural Genomics Consortium, University of Oxford, Oxford, UK
| | - Phoebe A Rice
- Department of Biochemistry and Molecular Biology, The University of Chicago, Chicago, Illinois
| | - Yufeng Tong
- Department of Chemistry and Biochemistry, University of Windsor, Windsor, Ontario, Canada.,Structural Genomics Consortium, University of Toronto, Toronto, Ontario, Canada
| | - Maya Topf
- Institute of Structural and Molecular Biology, Birkbeck, University College London, London, UK
| | - Jonathan D Walton
- Great Lakes Bioenergy Research Center and Department of Plant Biology, Michigan State University, East Lansing, Michigan
| | - Torsten Schwede
- Biozentrum University of Basel, Basel, Switzerland.,SIB Swiss Institute of Bioinformatics, Biozentrum University of Basel, Basel, Switzerland
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47
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Schneider JP, Nazarov S, Adaixo R, Liuzzo M, Ringel PD, Stahlberg H, Basler M. Diverse roles of TssA-like proteins in the assembly of bacterial type VI secretion systems. EMBO J 2019; 38:e100825. [PMID: 31403721 PMCID: PMC6745524 DOI: 10.15252/embj.2018100825] [Citation(s) in RCA: 20] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2018] [Revised: 07/08/2019] [Accepted: 07/16/2019] [Indexed: 01/01/2023] Open
Abstract
Protein translocation by the bacterial type VI secretion system (T6SS) is driven by a rapid contraction of a sheath assembled around a tube with associated effectors. Here, we show that TssA‐like or TagA‐like proteins with a conserved N‐terminal domain and varying C‐terminal domains can be grouped into at least three distinct classes based on their role in sheath assembly. The proteins of the first class increase speed and frequency of sheath assembly and form a stable dodecamer at the distal end of a polymerizing sheath. The proteins of the second class localize to the cell membrane and block sheath polymerization upon extension across the cell. This prevents excessive sheath polymerization and bending, which may result in sheath destabilization and detachment from its membrane anchor and thus result in failed secretion. The third class of these proteins localizes to the baseplate and is required for initiation of sheath assembly. Our work shows that while various proteins share a conserved N‐terminal domain, their roles in T6SS biogenesis are fundamentally different.
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Affiliation(s)
| | | | - Ricardo Adaixo
- Center for Cellular Imaging and NanoAnalytics (C-CINA), Biozentrum, University of Basel, Basel, Switzerland
| | | | | | - Henning Stahlberg
- Center for Cellular Imaging and NanoAnalytics (C-CINA), Biozentrum, University of Basel, Basel, Switzerland
| | - Marek Basler
- Biozentrum, University of Basel, Basel, Switzerland
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48
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Desfosses A, Venugopal H, Joshi T, Felix J, Jessop M, Jeong H, Hyun J, Heymann JB, Hurst MRH, Gutsche I, Mitra AK. Atomic structures of an entire contractile injection system in both the extended and contracted states. Nat Microbiol 2019; 4:1885-1894. [PMID: 31384001 PMCID: PMC6817355 DOI: 10.1038/s41564-019-0530-6] [Citation(s) in RCA: 37] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/05/2019] [Accepted: 07/02/2019] [Indexed: 02/07/2023]
Abstract
Contractile injection systems are sophisticated multiprotein nanomachines that puncture target cell membranes. While the amount of atomic resolution insights into contractile bacteriophage tails, bacterial type six secretion systems and R-pyocins is rapidly increasing, structural information about contraction of bacterial phage-like protein-translocation structures directed towards eukaryotic hosts is scarce. Here we characterise the antifeeding prophage AFP from Serratia entomophila by cryo-electron microscopy. We present the high-resolution structure of the entire AFP particle in the extended state, trace 11 protein chains de novo from the apical cap to the needle tip, describe localisation variants and perform specific structural comparisons with related systems. We analyse intersubunit interactions and highlight their universal conservation within contractile injection systems while revealing the specificities of AFP. Furthermore, we provide the structure of the AFP sheath-baseplate complex in a contracted state. This study reveals atomic details of interaction networks that accompany and define the contraction mechanism of toxin-delivery tailocins, offering a comprehensive framework for understanding their mode of action and for their possible adaptation as biocontrol agents.
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Affiliation(s)
- Ambroise Desfosses
- School of Biological Sciences, University of Auckland, Auckland, New Zealand.,Institut de Biologie Structurale (IBS), University Grenoble Alpes, CEA, CNRS, Grenoble, France
| | - Hariprasad Venugopal
- School of Biological Sciences, University of Auckland, Auckland, New Zealand.,Ramaciotti Centre for Cryo Electron Microscopy, Monash University, Melbourne, Victoria, Australia
| | - Tapan Joshi
- School of Biological Sciences, University of Auckland, Auckland, New Zealand
| | - Jan Felix
- Institut de Biologie Structurale (IBS), University Grenoble Alpes, CEA, CNRS, Grenoble, France
| | - Matthew Jessop
- School of Biological Sciences, University of Auckland, Auckland, New Zealand.,Institut de Biologie Structurale (IBS), University Grenoble Alpes, CEA, CNRS, Grenoble, France
| | - Hyengseop Jeong
- Electron Microscopy Research Center, Korea Basic Science Institute, Cheongju-si, Republic of Korea
| | - Jaekyung Hyun
- Electron Microscopy Research Center, Korea Basic Science Institute, Cheongju-si, Republic of Korea.,Molecular Cryo-Electron Microscopy Unit, Okinawa Institute of Science and Technology Graduate University, Okinawa, Japan
| | - J Bernard Heymann
- Laboratory for Structural Biology Research, National Institute of Arthritis, Musculoskeletal and Skin Diseases, National Institutes of Health, Bethesda, MD, USA
| | - Mark R H Hurst
- Forage Science, AgResearch, Lincoln Research Centre, Christchurch, New Zealand. .,Bio-Protection Research Centre, Christchurch, New Zealand.
| | - Irina Gutsche
- Institut de Biologie Structurale (IBS), University Grenoble Alpes, CEA, CNRS, Grenoble, France.
| | - Alok K Mitra
- School of Biological Sciences, University of Auckland, Auckland, New Zealand.
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49
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Abstract
Bacterial contractile injection systems are fascinating particles that use a spring-like mechanism to inject an effector-loaded needle into target cells. A recent study shows that the intracellular bacterium Amoebophilus asiaticus uses arrays of contractile structures to escape from the amoeba phagosome.
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Affiliation(s)
- Eric Cascales
- Laboratoire d'Ingénierie des Systèmes Macromoléculaires, Institut de Microbiologie de la Méditerranée, CNRS UMR7255, Aix-Marseille Université, Marseille Cedex 20, France.
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Chong PP, Chin VK, Looi CY, Wong WF, Madhavan P, Yong VC. The Microbiome and Irritable Bowel Syndrome - A Review on the Pathophysiology, Current Research and Future Therapy. Front Microbiol 2019; 10:1136. [PMID: 31244784 PMCID: PMC6579922 DOI: 10.3389/fmicb.2019.01136] [Citation(s) in RCA: 158] [Impact Index Per Article: 31.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/13/2018] [Accepted: 05/06/2019] [Indexed: 11/16/2022] Open
Abstract
Irritable bowel syndrome (IBS) is a functional disorder which affects a large proportion of the population globally. The precise etiology of IBS is still unknown, although consensus understanding proposes IBS to be of multifactorial origin with yet undefined subtypes. Genetic and epigenetic factors, stress-related nervous and endocrine systems, immune dysregulation and the brain-gut axis seem to be contributing factors that predispose individuals to IBS. In addition to food hypersensitivity, toxins and adverse life events, chronic infections and dysbiotic gut microbiota have been suggested to trigger IBS symptoms in tandem with the predisposing factors. This review will summarize the pathophysiology of IBS and the role of gut microbiota in relation to IBS. Current methodologies for microbiome studies in IBS such as genome sequencing, metagenomics, culturomics and animal models will be discussed. The myriad of therapy options such as immunoglobulins (immune-based therapy), probiotics and prebiotics, dietary modifications including FODMAP restriction diet and gluten-free diet, as well as fecal transplantation will be reviewed. Finally this review will highlight future directions in IBS therapy research, including identification of new molecular targets, application of 3-D gut model, gut-on-a-chip and personalized therapy.
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Affiliation(s)
- Pei Pei Chong
- School of Biosciences, Taylor's University, Subang Jaya, Malaysia
| | - Voon Kin Chin
- School of Biosciences, Taylor's University, Subang Jaya, Malaysia
| | - Chung Yeng Looi
- School of Biosciences, Taylor's University, Subang Jaya, Malaysia
| | - Won Fen Wong
- Department of Medical Microbiology, Faculty of Medicine, University of Malaya, Kuala Lumpur, Malaysia
| | - Priya Madhavan
- School of Medicine, Faculty of Health and Medical Sciences, Taylor's University, Subang Jaya, Malaysia
| | - Voon Chen Yong
- School of Biosciences, Taylor's University, Subang Jaya, Malaysia
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