1
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Zhao Q, Bertolli S, Park YJ, Tan Y, Cutler KJ, Srinivas P, Asfahl KL, Fonesca-García C, Gallagher LA, Li Y, Wang Y, Coleman-Derr D, DiMaio F, Zhang D, Peterson SB, Veesler D, Mougous JD. Streptomyces umbrella toxin particles block hyphal growth of competing species. Nature 2024; 629:165-173. [PMID: 38632398 PMCID: PMC11062931 DOI: 10.1038/s41586-024-07298-z] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/05/2023] [Accepted: 03/11/2024] [Indexed: 04/19/2024]
Abstract
Streptomyces are a genus of ubiquitous soil bacteria from which the majority of clinically utilized antibiotics derive1. The production of these antibacterial molecules reflects the relentless competition Streptomyces engage in with other bacteria, including other Streptomyces species1,2. Here we show that in addition to small-molecule antibiotics, Streptomyces produce and secrete antibacterial protein complexes that feature a large, degenerate repeat-containing polymorphic toxin protein. A cryo-electron microscopy structure of these particles reveals an extended stalk topped by a ringed crown comprising the toxin repeats scaffolding five lectin-tipped spokes, which led us to name them umbrella particles. Streptomyces coelicolor encodes three umbrella particles with distinct toxin and lectin composition. Notably, supernatant containing these toxins specifically and potently inhibits the growth of select Streptomyces species from among a diverse collection of bacteria screened. For one target, Streptomyces griseus, inhibition relies on a single toxin and that intoxication manifests as rapid cessation of vegetative hyphal growth. Our data show that Streptomyces umbrella particles mediate competition among vegetative mycelia of related species, a function distinct from small-molecule antibiotics, which are produced at the onset of reproductive growth and act broadly3,4. Sequence analyses suggest that this role of umbrella particles extends beyond Streptomyces, as we identified umbrella loci in nearly 1,000 species across Actinobacteria.
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Affiliation(s)
- Qinqin Zhao
- Department of Microbiology, University of Washington, Seattle, WA, USA
| | - Savannah Bertolli
- Department of Microbiology, University of Washington, Seattle, WA, USA
| | - Young-Jun Park
- Howard Hughes Medical Institute, University of Washington, Seattle, WA, USA
- Department of Biochemistry, University of Washington, Seattle, WA, USA
| | - Yongjun Tan
- Department of Biology, St Louis University, St Louis, MO, USA
| | - Kevin J Cutler
- Department of Microbiology, University of Washington, Seattle, WA, USA
- Department of Physics, University of Washington, Seattle, WA, USA
| | - Pooja Srinivas
- Department of Microbiology, University of Washington, Seattle, WA, USA
| | - Kyle L Asfahl
- Department of Microbiology, University of Washington, Seattle, WA, USA
- Microbial Interactions and Microbiome Center, University of Washington, Seattle, WA, USA
| | - Citlali Fonesca-García
- Plant Gene Expression Center, USDA-ARS, Albany, CA, USA
- Department of Plant and Microbial Biology, University of California Berkeley, Berkeley, CA, USA
| | - Larry A Gallagher
- Department of Microbiology, University of Washington, Seattle, WA, USA
| | - Yaqiao Li
- Department of Microbiology, University of Washington, Seattle, WA, USA
| | - Yaxi Wang
- Department of Microbiology, University of Washington, Seattle, WA, USA
| | - Devin Coleman-Derr
- Plant Gene Expression Center, USDA-ARS, Albany, CA, USA
- Department of Plant and Microbial Biology, University of California Berkeley, Berkeley, CA, USA
| | - Frank DiMaio
- Department of Biochemistry, University of Washington, Seattle, WA, USA
- Institute for Protein Design, University of Washington, Seattle, WA, USA
| | - Dapeng Zhang
- Department of Biology, St Louis University, St Louis, MO, USA
- Program of Bioinformatic and Computational Biology, St Louis University, St Louis, MO, USA
| | - S Brook Peterson
- Department of Microbiology, University of Washington, Seattle, WA, USA
| | - David Veesler
- Howard Hughes Medical Institute, University of Washington, Seattle, WA, USA
- Department of Biochemistry, University of Washington, Seattle, WA, USA
| | - Joseph D Mougous
- Department of Microbiology, University of Washington, Seattle, WA, USA.
- Howard Hughes Medical Institute, University of Washington, Seattle, WA, USA.
- Microbial Interactions and Microbiome Center, University of Washington, Seattle, WA, USA.
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2
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Humphreys IR, Zhang J, Baek M, Wang Y, Krishnakumar A, Pei J, Anishchenko I, Tower CA, Jackson BA, Warrier T, Hung DT, Peterson SB, Mougous JD, Cong Q, Baker D. Essential and virulence-related protein interactions of pathogens revealed through deep learning. bioRxiv 2024:2024.04.12.589144. [PMID: 38645026 PMCID: PMC11030334 DOI: 10.1101/2024.04.12.589144] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 04/23/2024]
Abstract
Identification of bacterial protein-protein interactions and predicting the structures of the complexes could aid in the understanding of pathogenicity mechanisms and developing treatments for infectious diseases. Here, we developed a deep learning-based pipeline that leverages residue-residue coevolution and protein structure prediction to systematically identify and structurally characterize protein-protein interactions at the proteome-wide scale. Using this pipeline, we searched through 78 million pairs of proteins across 19 human bacterial pathogens and identified 1923 confidently predicted complexes involving essential genes and 256 involving virulence factors. Many of these complexes were not previously known; we experimentally tested 12 such predictions, and half of them were validated. The predicted interactions span core metabolic and virulence pathways ranging from post-transcriptional modification to acid neutralization to outer membrane machinery and should contribute to our understanding of the biology of these important pathogens and the design of drugs to combat them.
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3
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Wang Y, Gallagher LA, Andrade PA, Liu A, Humphreys IR, Turkarslan S, Cutler KJ, Arrieta-Ortiz ML, Li Y, Radey MC, McLean JS, Cong Q, Baker D, Baliga NS, Peterson SB, Mougous JD. Genetic manipulation of Patescibacteria provides mechanistic insights into microbial dark matter and the epibiotic lifestyle. Cell 2023; 186:4803-4817.e13. [PMID: 37683634 PMCID: PMC10633639 DOI: 10.1016/j.cell.2023.08.017] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/11/2023] [Revised: 07/06/2023] [Accepted: 08/16/2023] [Indexed: 09/10/2023]
Abstract
Patescibacteria, also known as the candidate phyla radiation (CPR), are a diverse group of bacteria that constitute a disproportionately large fraction of microbial dark matter. Its few cultivated members, belonging mostly to Saccharibacteria, grow as epibionts on host Actinobacteria. Due to a lack of suitable tools, the genetic basis of this lifestyle and other unique features of Patescibacteira remain unexplored. Here, we show that Saccharibacteria exhibit natural competence, and we exploit this property for their genetic manipulation. Imaging of fluorescent protein-labeled Saccharibacteria provides high spatiotemporal resolution of phenomena accompanying epibiotic growth, and a transposon-insertion sequencing (Tn-seq) genome-wide screen reveals the contribution of enigmatic Saccharibacterial genes to growth on their hosts. Finally, we leverage metagenomic data to provide cutting-edge protein structure-based bioinformatic resources that support the strain Southlakia epibionticum and its corresponding host, Actinomyces israelii, as a model system for unlocking the molecular underpinnings of the epibiotic lifestyle.
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Affiliation(s)
- Yaxi Wang
- Department of Microbiology, University of Washington, Seattle, WA 98109, USA
| | - Larry A Gallagher
- Department of Microbiology, University of Washington, Seattle, WA 98109, USA
| | - Pia A Andrade
- Department of Microbiology, University of Washington, Seattle, WA 98109, USA
| | - Andi Liu
- Department of Microbiology, University of Washington, Seattle, WA 98109, USA
| | - Ian R Humphreys
- Department of Biochemistry, University of Washington, Seattle, WA 98195, USA; Institute for Protein Design, University of Washington, Seattle, WA 98195, USA
| | | | - Kevin J Cutler
- Department of Physics, University of Washington, Seattle, WA 98195, USA
| | | | - Yaqiao Li
- Department of Microbiology, University of Washington, Seattle, WA 98109, USA; Institute for Systems Biology, Seattle, WA 98109, USA
| | - Matthew C Radey
- Department of Microbiology, University of Washington, Seattle, WA 98109, USA
| | - Jeffrey S McLean
- Department of Microbiology, University of Washington, Seattle, WA 98109, USA; Department of Periodontics, University of Washington, Seattle, WA 98195, USA
| | - Qian Cong
- Eugene McDermott Center for Human Growth and Development, University of Texas Southwestern Medical Center, Dallas, TX 75390, USA; Department of Biophysics, University of Texas Southwestern Medical Center, Dallas, TX 75390, USA; Harold C. Simmons Comprehensive Cancer Center, University of Texas Southwestern Medical Center, Dallas, TX 75390, USA
| | - David Baker
- Department of Biochemistry, University of Washington, Seattle, WA 98195, USA; Institute for Protein Design, University of Washington, Seattle, WA 98195, USA; Howard Hughes Medical Institute, University of Washington, Seattle, WA 98109, USA
| | | | - S Brook Peterson
- Department of Microbiology, University of Washington, Seattle, WA 98109, USA
| | - Joseph D Mougous
- Department of Microbiology, University of Washington, Seattle, WA 98109, USA; Howard Hughes Medical Institute, University of Washington, Seattle, WA 98109, USA; Microbial Interactions and Microbiome Center, University of Washington, Seattle, WA 98195, USA.
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4
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Bosch DE, Abbasian R, Parajuli B, Peterson SB, Mougous JD. Structural disruption of Ntox15 nuclease effector domains by immunity proteins protects against type VI secretion system intoxication in Bacteroidales. mBio 2023; 14:e0103923. [PMID: 37345922 PMCID: PMC10470768 DOI: 10.1128/mbio.01039-23] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/25/2023] [Accepted: 05/03/2023] [Indexed: 06/23/2023] Open
Abstract
Bacteroidales use type VI secretion systems (T6SS) to competitively colonize and persist in the colon. We identify a horizontally transferred T6SS with Ntox15 family nuclease effector (Tde1) that mediates interbacterial antagonism among Bacteroidales, including several derived from a single human donor. Expression of cognate (Tdi1) or orphan immunity proteins in acquired interbacterial defense systems protects against Tde1-dependent attack. We find that immunity protein interaction induces a large effector conformational change in Tde nucleases, disrupting the active site and altering the DNA-binding site. Crystallographic snapshots of isolated Tde1, the Tde1/Tdi1 complex, and homologs from Phocaeicola vulgatus (Tde2/Tdi2) illustrate a conserved mechanism of immunity inserting into the central core of Tde, splitting the nuclease fold into two subdomains. The Tde/Tdi interface and immunity mechanism are distinct from all other polymorphic toxin-immunity interactions of known structure. Bacteroidales abundance has been linked to inflammatory bowel disease activity in prior studies, and we demonstrate that Tde and T6SS structural genes are each enriched in fecal metagenomes from ulcerative colitis subjects. Genetically mobile Tde1-encoding T6SS in Bacteroidales mediate competitive growth and may be involved in inflammatory bowel disease. Broad immunity is conferred by Tdi1 homologs through a fold-disrupting mechanism unique among polymorphic effector-immunity pairs of known structure. IMPORTANCE Bacteroidales are related to inflammatory bowel disease severity and progression. We identify type VI secretion system (T6SS) nuclease effectors (Tde) which are enriched in ulcerative colitis and horizontally transferred on mobile genetic elements. Tde-encoding T6SSs mediate interbacterial competition. Orphan and cognate immunity proteins (Tdi) prevent intoxication by multiple Tde through a new mechanism among polymorphic toxin systems. Tdi inserts into the effector central core, splitting Ntox15 into two subdomains and disrupting the active site. This mechanism may allow for evolutionary diversification of the Tde/Tdi interface as observed in colicin nuclease-immunity interactions, promoting broad neutralization of Tde by orphan Tdi. Tde-dependent T6SS interbacterial antagonism may contribute to Bacteroidales diversity in the context of ulcerative colitis.
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Affiliation(s)
- Dustin E. Bosch
- Department of Pathology, Carver College of Medicine, University of Iowa, Iowa City, Iowa, USA
| | - Romina Abbasian
- Department of Pathology, Carver College of Medicine, University of Iowa, Iowa City, Iowa, USA
| | - Bishal Parajuli
- Department of Pathology, Carver College of Medicine, University of Iowa, Iowa City, Iowa, USA
| | - S. Brook Peterson
- Department of Microbiology, University of Washington School of Medicine, Seattle, Washington, USA
- Howard Hughes Medical Institute, University of Washington, Seattle, Washington, USA
| | - Joseph D. Mougous
- Department of Microbiology, University of Washington School of Medicine, Seattle, Washington, USA
- Howard Hughes Medical Institute, University of Washington, Seattle, Washington, USA
- Microbial Interactions and Microbiome Center, University of Washington, Seattle, Washington, USA
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5
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Wang Y, Ledvina HE, Tower CA, Kambarev S, Liu E, Charity JC, Kreuk LSM, Tang Q, Chen Q, Gallagher LA, Radey MC, Rerolle GF, Li Y, Penewit KM, Turkarslan S, Skerrett SJ, Salipante SJ, Baliga NS, Woodward JJ, Dove SL, Peterson SB, Celli J, Mougous JD. Discovery of a glutathione utilization pathway in Francisella that shows functional divergence between environmental and pathogenic species. Cell Host Microbe 2023; 31:1359-1370.e7. [PMID: 37453420 PMCID: PMC10763578 DOI: 10.1016/j.chom.2023.06.010] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/25/2023] [Revised: 05/19/2023] [Accepted: 06/20/2023] [Indexed: 07/18/2023]
Abstract
Glutathione (GSH) is an abundant metabolite within eukaryotic cells that can act as a signal, a nutrient source, or serve in a redox capacity for intracellular bacterial pathogens. For Francisella, GSH is thought to be a critical in vivo source of cysteine; however, the cellular pathways permitting GSH utilization by Francisella differ between strains and have remained poorly understood. Using genetic screening, we discovered a unique pathway for GSH utilization in Francisella. Whereas prior work suggested GSH catabolism initiates in the periplasm, the pathway we define consists of a major facilitator superfamily (MFS) member that transports intact GSH and a previously unrecognized bacterial cytoplasmic enzyme that catalyzes the first step of GSH degradation. Interestingly, we find that the transporter gene for this pathway is pseudogenized in pathogenic Francisella, explaining phenotypic discrepancies in GSH utilization among Francisella spp. and revealing a critical role for GSH in the environmental niche of these bacteria.
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Affiliation(s)
- Yaxi Wang
- Department of Microbiology, University of Washington, Seattle, WA 98109, USA
| | - Hannah E Ledvina
- Department of Microbiology, University of Washington, Seattle, WA 98109, USA
| | - Catherine A Tower
- Department of Microbiology, University of Washington, Seattle, WA 98109, USA
| | - Stanimir Kambarev
- Paul G. Allen School for Global Health, Washington State University, Pullman, WA 99164, USA
| | - Elizabeth Liu
- Department of Microbiology, University of Washington, Seattle, WA 98109, USA
| | - James C Charity
- Division of Infectious Diseases, Boston Children's Hospital, Harvard Medical School, Boston, MA 02115, USA
| | | | - Qing Tang
- Department of Microbiology, University of Washington, Seattle, WA 98109, USA
| | - Qiwen Chen
- Department of Microbiology, University of Washington, Seattle, WA 98109, USA
| | - Larry A Gallagher
- Department of Microbiology, University of Washington, Seattle, WA 98109, USA
| | - Matthew C Radey
- Department of Microbiology, University of Washington, Seattle, WA 98109, USA
| | - Guilhem F Rerolle
- Department of Medicine, University of Washington, Seattle, WA 98195, USA
| | - Yaqiao Li
- Department of Microbiology, University of Washington, Seattle, WA 98109, USA; Institute for Systems Biology, Seattle, WA 98109, USA
| | - Kelsi M Penewit
- Department of Laboratory Medicine and Pathology, University of Washington, Seattle, WA 98195, USA
| | | | - Shawn J Skerrett
- Department of Medicine, University of Washington, Seattle, WA 98195, USA
| | - Stephen J Salipante
- Department of Laboratory Medicine and Pathology, University of Washington, Seattle, WA 98195, USA
| | | | - Joshua J Woodward
- Department of Microbiology, University of Washington, Seattle, WA 98109, USA
| | - Simon L Dove
- Division of Infectious Diseases, Boston Children's Hospital, Harvard Medical School, Boston, MA 02115, USA
| | - S Brook Peterson
- Department of Microbiology, University of Washington, Seattle, WA 98109, USA
| | - Jean Celli
- Paul G. Allen School for Global Health, Washington State University, Pullman, WA 99164, USA
| | - Joseph D Mougous
- Department of Microbiology, University of Washington, Seattle, WA 98109, USA; Microbial Interactions and Microbiome Center, University of Washington, Seattle, WA 98195, USA; Howard Hughes Medical Institute, University of Washington, Seattle, WA 98109, USA.
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6
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Wang Y, Gallagher LA, Andrade PA, Liu A, Humphreys IR, Turkarslan S, Cutler KJ, Arrieta-Ortiz ML, Li Y, Radey MC, McLean JS, Cong Q, Baker D, Baliga NS, Peterson SB, Mougous JD. Genetic manipulation of candidate phyla radiation bacteria provides functional insights into microbial dark matter. bioRxiv 2023:2023.05.02.539146. [PMID: 37205512 PMCID: PMC10187176 DOI: 10.1101/2023.05.02.539146] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/21/2023]
Abstract
The study of bacteria has yielded fundamental insights into cellular biology and physiology, biotechnological advances and many therapeutics. Yet due to a lack of suitable tools, the significant portion of bacterial diversity held within the candidate phyla radiation (CPR) remains inaccessible to such pursuits. Here we show that CPR bacteria belonging to the phylum Saccharibacteria exhibit natural competence. We exploit this property to develop methods for their genetic manipulation, including the insertion of heterologous sequences and the construction of targeted gene deletions. Imaging of fluorescent protein-labeled Saccharibacteria provides high spatiotemporal resolution of phenomena accompanying epibiotic growth and a transposon insertion sequencing genome-wide screen reveals the contribution of enigmatic Saccharibacterial genes to growth on their Actinobacteria hosts. Finally, we leverage metagenomic data to provide cutting-edge protein structure-based bioinformatic resources that support the strain Southlakia epibionticum and its corresponding host, Actinomyces israelii , as a model system for unlocking the molecular underpinnings of the epibiotic lifestyle.
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Affiliation(s)
- Yaxi Wang
- Department of Microbiology, University of Washington, Seattle, WA 98109, USA
| | - Larry A. Gallagher
- Department of Microbiology, University of Washington, Seattle, WA 98109, USA
| | - Pia A. Andrade
- Department of Microbiology, University of Washington, Seattle, WA 98109, USA
| | - Andi Liu
- Department of Microbiology, University of Washington, Seattle, WA 98109, USA
| | - Ian R. Humphreys
- Department of Biochemistry, University of Washington, Seattle, WA 98109, USA
- Institute for Protein Design, Seattle, WA 98109, USA
| | | | - Kevin J. Cutler
- Department of Physics, University of Washington, Seattle, WA 98195, USA
| | | | - Yaqiao Li
- Department of Microbiology, University of Washington, Seattle, WA 98109, USA
- Institute for Systems Biology, Seattle, WA 98109, USA
| | - Matthew C. Radey
- Department of Microbiology, University of Washington, Seattle, WA 98109, USA
| | - Jeffrey S. McLean
- Department of Microbiology, University of Washington, Seattle, WA 98109, USA
- Department of Periodontics, University of Washington, Seattle, WA 98195, USA
| | - Qian Cong
- Eugene McDermott Center for Human Growth and Development, University of Texas Southwestern Medical Center, Dallas, TX, USA
- Department of Biophysics, University of Texas Southwestern Medical Center, Dallas, TX, USA
- Harold C. Simmons Comprehensive Cancer Center, University of Texas Southwestern Medical Center, Dallas, TX, USA
| | - David Baker
- Department of Biochemistry, University of Washington, Seattle, WA 98109, USA
- Institute for Protein Design, Seattle, WA 98109, USA
- Howard Hughes Medical Institute, University of Washington, Seattle, WA 98195, USA
| | | | - S. Brook Peterson
- Department of Microbiology, University of Washington, Seattle, WA 98109, USA
| | - Joseph D. Mougous
- Department of Microbiology, University of Washington, Seattle, WA 98109, USA
- Howard Hughes Medical Institute, University of Washington, Seattle, WA 98195, USA
- Microbial Interactions and Microbiome Center, University of Washington, Seattle, WA 98109, USA
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7
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Cutler KJ, Stringer C, Lo TW, Rappez L, Stroustrup N, Brook Peterson S, Wiggins PA, Mougous JD. Omnipose: a high-precision morphology-independent solution for bacterial cell segmentation. Nat Methods 2022; 19:1438-1448. [PMID: 36253643 PMCID: PMC9636021 DOI: 10.1038/s41592-022-01639-4] [Citation(s) in RCA: 41] [Impact Index Per Article: 20.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/02/2021] [Accepted: 09/06/2022] [Indexed: 12/26/2022]
Abstract
Advances in microscopy hold great promise for allowing quantitative and precise measurement of morphological and molecular phenomena at the single-cell level in bacteria; however, the potential of this approach is ultimately limited by the availability of methods to faithfully segment cells independent of their morphological or optical characteristics. Here, we present Omnipose, a deep neural network image-segmentation algorithm. Unique network outputs such as the gradient of the distance field allow Omnipose to accurately segment cells on which current algorithms, including its predecessor, Cellpose, produce errors. We show that Omnipose achieves unprecedented segmentation performance on mixed bacterial cultures, antibiotic-treated cells and cells of elongated or branched morphology. Furthermore, the benefits of Omnipose extend to non-bacterial subjects, varied imaging modalities and three-dimensional objects. Finally, we demonstrate the utility of Omnipose in the characterization of extreme morphological phenotypes that arise during interbacterial antagonism. Our results distinguish Omnipose as a powerful tool for characterizing diverse and arbitrarily shaped cell types from imaging data.
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Affiliation(s)
- Kevin J Cutler
- Department of Physics, University of Washington, Seattle, WA, USA
| | | | - Teresa W Lo
- Department of Physics, University of Washington, Seattle, WA, USA
| | - Luca Rappez
- Centre for Genomic Regulation (CRG), The Barcelona Institute of Science and Technology, Barcelona, Spain
| | - Nicholas Stroustrup
- Centre for Genomic Regulation (CRG), The Barcelona Institute of Science and Technology, Barcelona, Spain
- Universitat Pompeu Fabra (UPF), Barcelona, Spain
| | - S Brook Peterson
- Department of Microbiology, University of Washington, Seattle, WA, USA
| | - Paul A Wiggins
- Department of Physics, University of Washington, Seattle, WA, USA.
- Department of Bioengineering, University of Washington, Seattle, WA, USA.
| | - Joseph D Mougous
- Department of Microbiology, University of Washington, Seattle, WA, USA.
- Howard Hughes Medical Institute, University of Washington, Seattle, WA, USA.
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8
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Gallagher LA, Velazquez E, Peterson SB, Charity JC, Radey MC, Gebhardt MJ, Hsu F, Shull LM, Cutler KJ, Macareno K, de Moraes MH, Penewit KM, Kim J, Andrade PA, LaFramboise T, Salipante SJ, Reniere ML, de Lorenzo V, Wiggins PA, Dove SL, Mougous JD. Genome-wide protein-DNA interaction site mapping in bacteria using a double-stranded DNA-specific cytosine deaminase. Nat Microbiol 2022; 7:844-855. [PMID: 35650286 PMCID: PMC9159945 DOI: 10.1038/s41564-022-01133-9] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/02/2021] [Accepted: 04/25/2022] [Indexed: 12/20/2022]
Abstract
DNA-protein interactions are central to fundamental cellular processes, yet widely implemented technologies for measuring these interactions on a genome scale in bacteria are laborious and capture only a snapshot of binding events. We devised a facile method for mapping DNA-protein interaction sites in vivo using the double-stranded DNA-specific cytosine deaminase toxin DddA. In 3D-seq (DddA-sequencing), strains containing DddA fused to a DNA-binding protein of interest accumulate characteristic mutations in DNA sequence adjacent to sites occupied by the DNA-bound fusion protein. High-depth sequencing enables detection of sites of increased mutation frequency in these strains, yielding genome-wide maps of DNA-protein interaction sites. We validated 3D-seq for four transcription regulators in two bacterial species, Pseudomonas aeruginosa and Escherichia coli. We show that 3D-seq offers ease of implementation, the ability to record binding event signatures over time and the capacity for single-cell resolution.
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Affiliation(s)
- Larry A Gallagher
- Department of Microbiology, University of Washington, Seattle, WA, USA
| | - Elena Velazquez
- Department of Microbiology, University of Washington, Seattle, WA, USA
- Systems Biology Department, National Center of Biotechnology CSIC, Madrid, Spain
| | - S Brook Peterson
- Department of Microbiology, University of Washington, Seattle, WA, USA
| | - James C Charity
- Division of Infectious Diseases, Boston Children's Hospital, Harvard Medical School, Boston, MA, USA
| | - Matthew C Radey
- Department of Microbiology, University of Washington, Seattle, WA, USA
| | - Michael J Gebhardt
- Division of Infectious Diseases, Boston Children's Hospital, Harvard Medical School, Boston, MA, USA
| | - FoSheng Hsu
- Department of Microbiology, University of Washington, Seattle, WA, USA
| | - Lauren M Shull
- Department of Microbiology, University of Washington, Seattle, WA, USA
| | - Kevin J Cutler
- Department of Physics, University of Washington, Seattle, WA, USA
| | - Keven Macareno
- Division of Infectious Diseases, Boston Children's Hospital, Harvard Medical School, Boston, MA, USA
| | | | - Kelsi M Penewit
- Department of Laboratory Medicine and Pathology, University of Washington, Seattle, WA, USA
| | - Jennifer Kim
- Department of Microbiology, University of Washington, Seattle, WA, USA
| | - Pia A Andrade
- Department of Microbiology, University of Washington, Seattle, WA, USA
| | - Thomas LaFramboise
- Department of Genetics and Genome Sciences, Case Western Reserve University, Cleveland, OH, USA
| | - Stephen J Salipante
- Department of Laboratory Medicine and Pathology, University of Washington, Seattle, WA, USA
| | | | - Victor de Lorenzo
- Systems Biology Department, National Center of Biotechnology CSIC, Madrid, Spain
| | - Paul A Wiggins
- Department of Microbiology, University of Washington, Seattle, WA, USA
- Department of Physics, University of Washington, Seattle, WA, USA
- Department of Bioengineering, University of Washington, Seattle, WA, USA
| | - Simon L Dove
- Division of Infectious Diseases, Boston Children's Hospital, Harvard Medical School, Boston, MA, USA.
| | - Joseph D Mougous
- Department of Microbiology, University of Washington, Seattle, WA, USA.
- Department of Biochemistry, University of Washington School of Medicine, Seattle, WA, USA.
- Howard Hughes Medical Institute, University of Washington, Seattle, WA, USA.
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9
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Ting SY, LaCourse KD, Ledvina HE, Zhang R, Radey MC, Kulasekara HD, Somavanshi R, Bertolli SK, Gallagher LA, Kim J, Penewit KM, Salipante SJ, Xu L, Peterson SB, Mougous JD. Discovery of coordinately regulated pathways that provide innate protection against interbacterial antagonism. eLife 2022; 11:74658. [PMID: 35175195 PMCID: PMC8926400 DOI: 10.7554/elife.74658] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/12/2021] [Accepted: 02/16/2022] [Indexed: 11/13/2022] Open
Abstract
Bacterial survival is fraught with antagonism, including that deriving from viruses and competing bacterial cells. It is now appreciated that bacteria mount complex antiviral responses; however, whether a coordinated defense against bacterial threats is undertaken is not well understood. Previously, we showed that Pseudomonas aeruginosa possess a danger-sensing pathway that is a critical fitness determinant during competition against other bacteria. Here, we conducted genome-wide screens in P. aeruginosa that reveal three conserved and widespread interbacterial antagonism resistance clusters (arc1-3). We find that although arc1-3 are coordinately activated by the Gac/Rsm danger-sensing system, they function independently and provide idiosyncratic defense capabilities, distinguishing them from general stress response pathways. Our findings demonstrate that Arc3 family proteins provide specific protection against phospholipase toxins by preventing the accumulation of lysophospholipids in a manner distinct from previously characterized membrane repair systems. These findings liken the response of P. aeruginosa to bacterial threats to that of eukaryotic innate immunity, wherein threat detection leads to the activation of specialized defense systems.
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Affiliation(s)
- See-Yeun Ting
- Department of Microbiology, University of Washington School of MedicineSeattleUnited States
| | - Kaitlyn D LaCourse
- Department of Microbiology, University of Washington School of MedicineSeattleUnited States
| | - Hannah E Ledvina
- Department of Microbiology, University of Washington School of MedicineSeattleUnited States
| | - Rutan Zhang
- Department of Medicinal Chemistry, University of Washington School of PharmacySeattleUnited States
| | - Matthew C Radey
- Department of Microbiology, University of Washington School of MedicineSeattleUnited States
| | - Hemantha D Kulasekara
- Department of Microbiology, University of Washington School of MedicineSeattleUnited States
| | - Rahul Somavanshi
- Department of Microbiology, University of Washington School of MedicineSeattleUnited States
| | - Savannah K Bertolli
- Department of Microbiology, University of Washington School of MedicineSeattleUnited States
| | - Larry A Gallagher
- Department of Microbiology, University of Washington School of MedicineSeattleUnited States
| | - Jennifer Kim
- Department of Microbiology, University of Washington School of MedicineSeattleUnited States
| | - Kelsi M Penewit
- Department of Laboratory Medicine and Pathology, University of Washington School of MedicineSeattleUnited States
| | - Stephen J Salipante
- Department of Laboratory Medicine and Pathology, University of Washington School of MedicineSeattleUnited States
| | - Libin Xu
- Department of Medicinal Chemistry, University of Washington School of PharmacySeattleUnited States
| | - S Brook Peterson
- Department of Microbiology, University of Washington School of MedicineSeattleUnited States
| | - Joseph D Mougous
- Department of Microbiology, University of Washington School of MedicineSeattleUnited States,Department of Biochemistry, University of Washington School of MedicineSeattleUnited States,Howard Hughes Medical Institute, University of WashingtonSeattleUnited States
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10
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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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11
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de Moraes MH, Hsu F, Huang D, Bosch DE, Zeng J, Radey MC, Simon N, Ledvina HE, Frick JP, Wiggins PA, Peterson SB, Mougous JD. An interbacterial DNA deaminase toxin directly mutagenizes surviving target populations. eLife 2021; 10:62967. [PMID: 33448264 PMCID: PMC7901873 DOI: 10.7554/elife.62967] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/11/2020] [Accepted: 01/14/2021] [Indexed: 12/12/2022] Open
Abstract
When bacterial cells come in contact, antagonism mediated by the delivery of toxins frequently ensues. The potential for such encounters to have long-term beneficial consequences in recipient cells has not been investigated. Here, we examined the effects of intoxication by DddA, a cytosine deaminase delivered via the type VI secretion system (T6SS) of Burkholderia cenocepacia. Despite its killing potential, we observed that several bacterial species resist DddA and instead accumulate mutations. These mutations can lead to the acquisition of antibiotic resistance, indicating that even in the absence of killing, interbacterial antagonism can have profound consequences on target populations. Investigation of additional toxins from the deaminase superfamily revealed that mutagenic activity is a common feature of these proteins, including a representative we show targets single-stranded DNA and displays a markedly divergent structure. Our findings suggest that a surprising consequence of antagonistic interactions between bacteria could be the promotion of adaptation via the action of directly mutagenic toxins.
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Affiliation(s)
- Marcos H de Moraes
- Department of Microbiology, University of Washington School of Medicine, Seattle, United States
| | - FoSheng Hsu
- Department of Microbiology, University of Washington School of Medicine, Seattle, United States
| | - Dean Huang
- Department of Physics, University of Washington, Seattle, United States
| | - Dustin E Bosch
- Department of Laboratory Medicine and Pathology, University of Washington School of Medicine, Seattle, United States
| | - Jun Zeng
- Department of Microbiology, University of Washington School of Medicine, Seattle, United States
| | - Matthew C Radey
- Department of Microbiology, University of Washington School of Medicine, Seattle, United States
| | - Noah Simon
- Department of Biostatistics, University of Washington School of Public Health, Seattle, United States
| | - Hannah E Ledvina
- Department of Microbiology, University of Washington School of Medicine, Seattle, United States
| | - Jacob P Frick
- Department of Microbiology, University of Washington School of Medicine, Seattle, United States
| | - Paul A Wiggins
- Department of Physics, University of Washington, Seattle, United States
| | - S Brook Peterson
- Department of Microbiology, University of Washington School of Medicine, Seattle, United States
| | - Joseph D Mougous
- Department of Microbiology, University of Washington School of Medicine, Seattle, United States.,Department of Biochemistry, University of Washington School of Medicine, Seattle, United States.,Howard Hughes Medical Institute, University of Washington, Seattle, United States
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12
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Ting SY, Martínez-García E, Huang S, Bertolli SK, Kelly KA, Cutler KJ, Su ED, Zhi H, Tang Q, Radey MC, Raffatellu M, Peterson SB, de Lorenzo V, Mougous JD. Targeted Depletion of Bacteria from Mixed Populations by Programmable Adhesion with Antagonistic Competitor Cells. Cell Host Microbe 2020; 28:313-321.e6. [PMID: 32470328 PMCID: PMC7725374 DOI: 10.1016/j.chom.2020.05.006] [Citation(s) in RCA: 28] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/18/2020] [Revised: 04/21/2020] [Accepted: 05/06/2020] [Indexed: 01/15/2023]
Abstract
Selective and targeted removal of individual species or strains of bacteria from complex communities can be desirable over traditional, broadly acting antibacterials in several contexts. However, generalizable strategies that accomplish this with high specificity have been slow to emerge. Here we develop programmed inhibitor cells (PICs) that direct the potent antibacterial activity of the type VI secretion system (T6SS) against specified target cells. The PICs express surface-displayed nanobodies that mediate antigen-specific cell-cell adhesion to effectively overcome the barrier to T6SS activity in fluid conditions. We demonstrate the capacity of PICs to efficiently deplete low-abundance target bacteria without significant collateral damage to complex microbial communities. The only known requirements for PIC targeting are a Gram-negative cell envelope and a unique cell surface antigen; therefore, this approach should be generalizable to a wide array of bacteria and find application in medical, research, and environmental settings.
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Affiliation(s)
- See-Yeun Ting
- Department of Microbiology, University of Washington School of Medicine, Seattle, WA 98195, USA
| | | | - Shuo Huang
- 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
| | - Katherine A Kelly
- Department of Microbiology, University of Washington School of Medicine, Seattle, WA 98195, USA
| | - Kevin J Cutler
- Department of Physics, University of Washington, Seattle, WA 98195, USA
| | - Elizabeth D Su
- Department of Microbiology, University of Washington School of Medicine, Seattle, WA 98195, USA
| | - Hui Zhi
- Division of Host-Microbe Systems & Therapeutics, Department of Pediatrics, University of California San Diego, La Jolla, CA 92093, USA
| | - Qing Tang
- Department of Microbiology, University of Washington School of Medicine, Seattle, WA 98195, USA
| | - Matthew C Radey
- Department of Microbiology, University of Washington School of Medicine, Seattle, WA 98195, USA
| | - Manuela Raffatellu
- Division of Host-Microbe Systems & Therapeutics, Department of Pediatrics, University of California San Diego, La Jolla, CA 92093, USA; Center for Microbiome Innovation, University of California San Diego, La Jolla, CA 92093, USA; Chiba University-UC San Diego Center for Mucosal Immunology, Allergy, and Vaccines (CU-UCSD cMAV), La Jolla, CA 92093, USA
| | - S Brook Peterson
- Department of Microbiology, University of Washington School of Medicine, Seattle, WA 98195, USA
| | - Víctor de Lorenzo
- System Biology Program, National Center of Biotechnology CSIC, 28049 Madrid, Spain
| | - Joseph D Mougous
- Department of Microbiology, University of Washington School of Medicine, Seattle, WA 98195, USA; Department of Biochemistry, University of Washington School of Medicine, Seattle, WA 98195, USA; Howard Hughes Medical Institute, University of Washington, Seattle, WA 98195, USA.
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13
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Mok BY, de Moraes MH, Zeng J, Bosch DE, Kotrys AV, Raguram A, Hsu F, Radey MC, Peterson SB, Mootha VK, Mougous JD, Liu DR. A bacterial cytidine deaminase toxin enables CRISPR-free mitochondrial base editing. Nature 2020; 583:631-637. [PMID: 32641830 PMCID: PMC7381381 DOI: 10.1038/s41586-020-2477-4] [Citation(s) in RCA: 351] [Impact Index Per Article: 87.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/25/2020] [Accepted: 05/26/2020] [Indexed: 12/21/2022]
Abstract
Bacterial toxins represent a vast reservoir of biochemical diversity that can be repurposed for biomedical applications. Such proteins include a group of predicted interbacterial toxins of the deaminase superfamily, members of which have found application in gene-editing techniques1,2. Because previously described cytidine deaminases operate on single-stranded nucleic acids3, their use in base editing requires the unwinding of double-stranded DNA (dsDNA)-for example by a CRISPR-Cas9 system. Base editing within mitochondrial DNA (mtDNA), however, has thus far been hindered by challenges associated with the delivery of guide RNA into the mitochondria4. As a consequence, manipulation of mtDNA to date has been limited to the targeted destruction of the mitochondrial genome by designer nucleases9,10.Here we describe an interbacterial toxin, which we name DddA, that catalyses the deamination of cytidines within dsDNA. We engineered split-DddA halves that are non-toxic and inactive until brought together on target DNA by adjacently bound programmable DNA-binding proteins. Fusions of the split-DddA halves, transcription activator-like effector array proteins, and a uracil glycosylase inhibitor resulted in RNA-free DddA-derived cytosine base editors (DdCBEs) that catalyse C•G-to-T•A conversions in human mtDNA with high target specificity and product purity. We used DdCBEs to model a disease-associated mtDNA mutation in human cells, resulting in changes in respiration rates and oxidative phosphorylation. CRISPR-free DdCBEs enable the precise manipulation of mtDNA, rather than the elimination of mtDNA copies that results from its cleavage by targeted nucleases, with broad implications for the study and potential treatment of mitochondrial disorders.
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Affiliation(s)
- Beverly Y Mok
- Merkin Institute of Transformative Technologies in Healthcare, Broad Institute of MIT and Harvard, Cambridge, MA, USA
- Department of Chemistry and Chemical Biology, Harvard University, Cambridge, MA, USA
- Howard Hughes Medical Institute, Harvard University, Cambridge, MA, USA
| | - Marcos H de Moraes
- Department of Microbiology, University of Washington School of Medicine, Seattle, WA, USA
| | - Jun Zeng
- Department of Microbiology, University of Washington School of Medicine, Seattle, WA, USA
| | - Dustin E Bosch
- Department of Microbiology, University of Washington School of Medicine, Seattle, WA, USA
- Department of Pathology, University of Washington School of Medicine, Seattle, WA, USA
| | - Anna V Kotrys
- Howard Hughes Medical Institute and Department of Molecular Biology, Massachusetts General Hospital, Harvard Medical School, Boston, MA, USA
- Broad Institute of MIT and Harvard, Cambridge, MA, USA
- Institute of Biochemistry and Biophysics Polish Academy of Sciences, Warsaw, Poland
| | - Aditya Raguram
- Merkin Institute of Transformative Technologies in Healthcare, Broad Institute of MIT and Harvard, Cambridge, MA, USA
- Department of Chemistry and Chemical Biology, Harvard University, Cambridge, MA, USA
- Howard Hughes Medical Institute, Harvard University, Cambridge, MA, USA
| | - FoSheng Hsu
- Department of Microbiology, University of Washington School of Medicine, Seattle, WA, USA
| | - Matthew C Radey
- Department of Microbiology, University of Washington School of Medicine, Seattle, WA, USA
| | - S Brook Peterson
- Department of Microbiology, University of Washington School of Medicine, Seattle, WA, USA
| | - Vamsi K Mootha
- Howard Hughes Medical Institute and Department of Molecular Biology, Massachusetts General Hospital, Harvard Medical School, Boston, MA, USA
- Broad Institute of MIT and Harvard, Cambridge, MA, USA
| | - Joseph D Mougous
- Department of Microbiology, University of Washington School of Medicine, Seattle, WA, USA.
- Department of Biochemistry, University of Washington School of Medicine, Seattle, WA, USA.
- Howard Hughes Medical Institute, University of Washington, Seattle, WA, USA.
| | - David R Liu
- Merkin Institute of Transformative Technologies in Healthcare, Broad Institute of MIT and Harvard, Cambridge, MA, USA.
- Department of Chemistry and Chemical Biology, Harvard University, Cambridge, MA, USA.
- Howard Hughes Medical Institute, Harvard University, Cambridge, MA, USA.
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14
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Ramsey KM, Ledvina HE, Tresko TM, Wandzilak JM, Tower CA, Tallo T, Schramm CE, Peterson SB, Skerrett SJ, Mougous JD, Dove SL. Tn-Seq reveals hidden complexity in the utilization of host-derived glutathione in Francisella tularensis. PLoS Pathog 2020; 16:e1008566. [PMID: 32492066 PMCID: PMC7340319 DOI: 10.1371/journal.ppat.1008566] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/09/2020] [Revised: 07/07/2020] [Accepted: 04/20/2020] [Indexed: 12/27/2022] Open
Abstract
Host-derived glutathione (GSH) is an essential source of cysteine for the intracellular pathogen Francisella tularensis. In a comprehensive transposon insertion sequencing screen, we identified several F. tularensis genes that play central and previously unappreciated roles in the utilization of GSH during the growth of the bacterium in macrophages. We show that one of these, a gene we named dptA, encodes a proton-dependent oligopeptide transporter that enables growth of the organism on the dipeptide Cys-Gly, a key breakdown product of GSH generated by the enzyme γ-glutamyltranspeptidase (GGT). Although GGT was thought to be the principal enzyme involved in GSH breakdown in F. tularensis, our screen identified a second enzyme, referred to as ChaC, that is also involved in the utilization of exogenous GSH. However, unlike GGT and DptA, we show that the importance of ChaC in supporting intramacrophage growth extends beyond cysteine acquisition. Taken together, our findings provide a compendium of F. tularensis genes required for intracellular growth and identify new players in the metabolism of GSH that could be attractive targets for therapeutic intervention.
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Affiliation(s)
- Kathryn M. Ramsey
- Division of Infectious Diseases, Boston Children’s Hospital, Harvard Medical School, Boston, Massachusetts, United States of America
- Departments of Cell and Molecular Biology and Biomedical and Pharmaceutical Sciences, University of Rhode Island, Kingston, Rhode Island, United States of America
| | - Hannah E. Ledvina
- Department of Microbiology, University of Washington School of Medicine, Seattle, Washington, United States of America
| | - Tenayaann M. Tresko
- Department of Microbiology, University of Washington School of Medicine, Seattle, Washington, United States of America
| | - Jamie M. Wandzilak
- Departments of Cell and Molecular Biology and Biomedical and Pharmaceutical Sciences, University of Rhode Island, Kingston, Rhode Island, United States of America
| | - Catherine A. Tower
- Department of Microbiology, University of Washington School of Medicine, Seattle, Washington, United States of America
| | - Thomas Tallo
- Division of Infectious Diseases, Boston Children’s Hospital, Harvard Medical School, Boston, Massachusetts, United States of America
| | - Caroline E. Schramm
- Division of Pulmonary, Critical Care and Sleep Medicine, Harborview Medical Center, University of Washington, Seattle, Washington, United States of America
| | - S. Brook Peterson
- Department of Microbiology, University of Washington School of Medicine, Seattle, Washington, United States of America
| | - Shawn J. Skerrett
- Division of Pulmonary, Critical Care and Sleep Medicine, Harborview Medical Center, University of Washington, Seattle, Washington, United States of America
| | - Joseph D. Mougous
- Department of Microbiology, University of Washington School of Medicine, Seattle, Washington, United States of America
- Howard Hughes Medical Institute, University of Washington, Seattle, Washington, United States of America
| | - Simon L. Dove
- Division of Infectious Diseases, Boston Children’s Hospital, Harvard Medical School, Boston, Massachusetts, United States of America
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15
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Park YJ, Lacourse KD, Cambillau C, DiMaio F, Mougous JD, Veesler D. Structure of the type VI secretion system TssK-TssF-TssG baseplate subcomplex revealed by cryo-electron microscopy. Nat Commun 2018; 9:5385. [PMID: 30568167 PMCID: PMC6300606 DOI: 10.1038/s41467-018-07796-5] [Citation(s) in RCA: 29] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/18/2018] [Accepted: 11/22/2018] [Indexed: 11/13/2022] Open
Abstract
Type VI secretion systems (T6SSs) translocate effectors into target cells and are made of a contractile sheath and a tube docked onto a multi-protein transmembrane complex via a baseplate. Although some information is available about the mechanisms of tail contraction leading to effector delivery, the detailed architecture and function of the baseplate remain unknown. Here, we report the 3.7 Å resolution cryo-electron microscopy reconstruction of an enteroaggregative Escherichia coli baseplate subcomplex assembled from TssK, TssF and TssG. The structure reveals two TssK trimers interact with a locally pseudo-3-fold symmetrical complex comprising two copies of TssF and one copy of TssG. TssF and TssG are structurally related to each other and to components of the phage T4 baseplate and of the type IV secretion system, strengthening the evolutionary relationships among these macromolecular machines. These results, together with bacterial two-hybrid assays, provide a structural framework to understand the T6SS baseplate architecture.
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Affiliation(s)
- Young-Jun Park
- Department of Biochemistry, University of Washington, Seattle, WA, 98195, USA
| | - Kaitlyn D Lacourse
- Department of Microbiology, University of Washington, Seattle, WA, 98195, USA
| | - Christian Cambillau
- Architecture et Fonction des Macromolecules Biologiques, Aix-Marseille Universite, CNRS, Campus de Luminy, Case 932, 13288, Marseille, Cedex 09, France
| | - Frank DiMaio
- Department of Biochemistry, University of Washington, Seattle, WA, 98195, USA
| | - Joseph D Mougous
- Department of Microbiology, University of Washington, Seattle, WA, 98195, USA
- Howard Hughes Medical Institute, University of Washington, Seattle, WA, 98195, USA
| | - David Veesler
- Department of Biochemistry, University of Washington, Seattle, WA, 98195, USA.
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16
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Ting SY, Bosch DE, Mangiameli SM, Radey MC, Huang S, Park YJ, Kelly KA, Filip SK, Goo YA, Eng JK, Allaire M, Veesler D, Wiggins PA, Peterson SB, Mougous JD. Bifunctional Immunity Proteins Protect Bacteria against FtsZ-Targeting ADP-Ribosylating Toxins. Cell 2018; 175:1380-1392.e14. [PMID: 30343895 PMCID: PMC6239978 DOI: 10.1016/j.cell.2018.09.037] [Citation(s) in RCA: 72] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/14/2018] [Revised: 08/13/2018] [Accepted: 09/18/2018] [Indexed: 12/31/2022]
Abstract
ADP-ribosylation of proteins can profoundly impact their function and serves as an effective mechanism by which bacterial toxins impair eukaryotic cell processes. Here, we report the discovery that bacteria also employ ADP-ribosylating toxins against each other during interspecies competition. We demonstrate that one such toxin from Serratia proteamaculans interrupts the division of competing cells by modifying the essential bacterial tubulin-like protein, FtsZ, adjacent to its protomer interface, blocking its capacity to polymerize. The structure of the toxin in complex with its immunity determinant revealed two distinct modes of inhibition: active site occlusion and enzymatic removal of ADP-ribose modifications. We show that each is sufficient to support toxin immunity; however, the latter additionally provides unprecedented broad protection against non-cognate ADP-ribosylating effectors. Our findings reveal how an interbacterial arms race has produced a unique solution for safeguarding the integrity of bacterial cell division machinery against inactivating post-translational modifications.
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Affiliation(s)
- See-Yeun Ting
- Department of Microbiology, University of Washington School of Medicine, Seattle, WA 98195, USA
| | - Dustin E Bosch
- Department of Pathology, University of Washington School of Medicine, Seattle, WA 98195, USA
| | | | - Matthew C Radey
- Department of Microbiology, University of Washington School of Medicine, Seattle, WA 98195, USA
| | - Shuo Huang
- Department of Microbiology, University of Washington School of Medicine, Seattle, WA 98195, USA
| | - Young-Jun Park
- Department of Biochemistry, University of Washington School of Medicine, Seattle, WA 98195, USA
| | - Katherine A Kelly
- Department of Microbiology, University of Washington School of Medicine, Seattle, WA 98195, USA
| | | | - Young Ah Goo
- Proteomics Center of Excellence, Northwestern University, Chicago, IL 60611, USA
| | - Jimmy K Eng
- Proteomics Resource, University of Washington, Seattle, WA 98195, USA
| | - Marc Allaire
- Molecular Biophysics and Integrated Bioimaging, Lawrence Berkeley National Laboratory, Berkeley, CA 94720, USA
| | - David Veesler
- Department of Biochemistry, University of Washington School of Medicine, Seattle, WA 98195, USA
| | - Paul A Wiggins
- Department of Microbiology, University of Washington School of Medicine, Seattle, WA 98195, USA; Department of Physics, University of Washington, Seattle, WA 98195, USA; Department of Bioengineering, University of Washington, Seattle, WA 98195, USA
| | - S Brook Peterson
- Department of Microbiology, University of Washington School of Medicine, Seattle, WA 98195, USA
| | - Joseph D Mougous
- Department of Microbiology, University of Washington School of Medicine, Seattle, WA 98195, USA; Department of Biochemistry, University of Washington School of Medicine, Seattle, WA 98195, USA; Howard Hughes Medical Institute, University of Washington, Seattle, WA 98195, USA.
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17
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Quentin D, Ahmad S, Shanthamoorthy P, Mougous JD, Whitney JC, Raunser S. Mechanism of loading and translocation of type VI secretion system effector Tse6. Nat Microbiol 2018; 3:1142-1152. [PMID: 30177742 DOI: 10.1038/s41564-018-0238-z] [Citation(s) in RCA: 60] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/10/2018] [Accepted: 08/02/2018] [Indexed: 12/26/2022]
Abstract
The type VI secretion system (T6SS) primarily functions to mediate antagonistic interactions between contacting bacterial cells, but also mediates interactions with eukaryotic hosts. This molecular machine secretes antibacterial effector proteins by undergoing cycles of extension and contraction; however, how effectors are loaded into the T6SS and subsequently delivered to target bacteria remains poorly understood. Here, using electron cryomicroscopy, we analysed the structures of the Pseudomonas aeruginosa effector Tse6 loaded onto the T6SS spike protein VgrG1 in solution and embedded in lipid nanodiscs. In the absence of membranes, Tse6 stability requires the chaperone EagT6, two dimers of which interact with the hydrophobic transmembrane domains of Tse6. EagT6 is not directly involved in Tse6 delivery but is crucial for its loading onto VgrG1. VgrG1-loaded Tse6 spontaneously enters membranes and its toxin domain translocates across a lipid bilayer, indicating that effector delivery by the T6SS does not require puncturing of the target cell inner membrane by VgrG1. Eag chaperone family members from diverse Proteobacteria are often encoded adjacent to putative toxins with predicted transmembrane domains and we therefore anticipate that our findings will be generalizable to numerous T6SS-exported membrane-associated effectors.
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Affiliation(s)
- Dennis Quentin
- Department of Structural Biochemistry, Max Planck Institute of Molecular Physiology, Dortmund, Germany
| | - Shehryar Ahmad
- Michael DeGroote Institute for Infectious Disease Research, McMaster University, Hamilton, Ontario, Canada.,Department of Biochemistry and Biomedical Sciences, McMaster University, Hamilton, Ontario, Canada
| | - Premy Shanthamoorthy
- Michael DeGroote Institute for Infectious Disease Research, McMaster University, Hamilton, Ontario, Canada.,Department of Biochemistry and Biomedical Sciences, McMaster University, Hamilton, Ontario, Canada
| | - Joseph D Mougous
- Department of Microbiology, University of Washington, Seattle, WA, USA.,Howard Hughes Medical Institute, Seattle, WA, USA
| | - John C Whitney
- Michael DeGroote Institute for Infectious Disease Research, McMaster University, Hamilton, Ontario, Canada. .,Department of Biochemistry and Biomedical Sciences, McMaster University, Hamilton, Ontario, Canada.
| | - Stefan Raunser
- Department of Structural Biochemistry, Max Planck Institute of Molecular Physiology, Dortmund, Germany.
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18
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Verster AJ, Ross BD, Radey MC, Bao Y, Goodman AL, Mougous JD, Borenstein E. The Landscape of Type VI Secretion across Human Gut Microbiomes Reveals Its Role in Community Composition. Cell Host Microbe 2018; 22:411-419.e4. [PMID: 28910638 DOI: 10.1016/j.chom.2017.08.010] [Citation(s) in RCA: 91] [Impact Index Per Article: 15.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/18/2017] [Revised: 07/07/2017] [Accepted: 08/22/2017] [Indexed: 11/28/2022]
Abstract
Although gut microbiome composition is well defined, the mechanisms underlying community assembly remain poorly understood. Bacteroidales possess three genetic architectures (GA1-3) of the type VI secretion system (T6SS), an effector delivery pathway that mediates interbacterial competition. Here we define the distribution and role of GA1-3 in the human gut using metagenomic analysis. We find that adult microbiomes harbor limited effector and cognate immunity genes, suggesting selection for compatibility at the species (GA1 and GA2) and strain (GA3) levels. Bacteroides fragilis GA3 is known to mediate potent inter-strain competition, and we observe GA3 enrichment among strains colonizing infant microbiomes, suggesting competition early in life. Additionally, GA3 is associated with increased Bacteroides abundance, indicating that this system confers an advantage in Bacteroides-rich ecosystems. Collectively, these analyses uncover the prevalence of T6SS-dependent competition and reveal its potential role in shaping human gut microbial composition.
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Affiliation(s)
- Adrian J Verster
- Department of Genome Sciences, University of Washington, Seattle, WA 98195, USA
| | - Benjamin D Ross
- Department of Microbiology, School of Medicine, University of Washington, Seattle, WA 98195, USA
| | - Matthew C Radey
- Department of Microbiology, School of Medicine, University of Washington, Seattle, WA 98195, USA
| | - Yiqiao Bao
- Department of Microbial Pathogenesis, Yale University School of Medicine, New Haven, CT 06510, USA; Microbial Sciences Institute, Yale University School of Medicine, West Haven, CT 06516, USA
| | - Andrew L Goodman
- Department of Microbial Pathogenesis, Yale University School of Medicine, New Haven, CT 06510, USA; Microbial Sciences Institute, Yale University School of Medicine, West Haven, CT 06516, USA
| | - Joseph D Mougous
- Department of Microbiology, School of Medicine, University of Washington, Seattle, WA 98195, USA; Howard Hughes Medical Institute, School of Medicine, University of Washington, Seattle, WA 98195, USA.
| | - Elhanan Borenstein
- Department of Genome Sciences, University of Washington, Seattle, WA 98195, USA; Department of Computer Science and Engineering, University of Washington, Seattle, WA 98195, USA; Santa Fe Institute, Santa Fe, NM 87501, USA.
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19
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LaCourse KD, Peterson SB, Kulasekara HD, Radey MC, Kim J, Mougous JD. Conditional toxicity and synergy drive diversity among antibacterial effectors. Nat Microbiol 2018; 3:440-446. [PMID: 29459733 PMCID: PMC5876133 DOI: 10.1038/s41564-018-0113-y] [Citation(s) in RCA: 73] [Impact Index Per Article: 12.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/17/2017] [Accepted: 01/16/2018] [Indexed: 12/19/2022]
Abstract
Bacteria in polymicrobial habitats contend with a persistent barrage of competitors, often under rapidly changing environmental conditions1. The direct antagonism of competitor cells is thus an important bacterial survival strategy2. Towards this end, many bacterial species employ an arsenal of antimicrobial effectors with multiple activities; however, the benefits conferred by the simultaneous deployment of diverse toxins are unknown. Here we show that the multiple effectors delivered to competitor bacteria by the type VI secretion system (T6SS) of Pseudomonas aeruginosa display conditional efficacy and act synergistically. One of these effectors, Tse4, is most active in high salinity environments and synergizes with effectors that degrade the cell wall or inactivate intracellular electron carriers. We find Tse4 synergizes with these disparate mechanisms by forming pores that disrupt the ΔΨ component of the proton motive force. Our results provide evidence that the concomitant delivery of a cocktail of effectors serves as a bet-hedging strategy to promote bacterial competitiveness in the face of unpredictable and variable environmental conditions.
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Affiliation(s)
| | - S Brook Peterson
- Department of Microbiology, University of Washington, Seattle, WA, USA
| | | | - Matthew C Radey
- Department of Microbiology, University of Washington, Seattle, WA, USA
| | - Jungyun Kim
- Department of Microbiology, University of Washington, Seattle, WA, USA
| | - Joseph D Mougous
- Department of Microbiology, University of Washington, Seattle, WA, USA. .,Howard Hughes Medical Institute, University of Washington, Seattle, WA, USA.
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20
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Eshraghi A, Kim J, Walls AC, Ledvina HE, Miller CN, Ramsey KM, Whitney JC, Radey MC, Peterson SB, Ruhland BR, Tran BQ, Goo YA, Goodlett DR, Dove SL, Celli J, Veesler D, Mougous JD. Secreted Effectors Encoded within and outside of the Francisella Pathogenicity Island Promote Intramacrophage Growth. Cell Host Microbe 2017; 20:573-583. [PMID: 27832588 PMCID: PMC5384264 DOI: 10.1016/j.chom.2016.10.008] [Citation(s) in RCA: 53] [Impact Index Per Article: 7.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/19/2016] [Revised: 09/18/2016] [Accepted: 10/13/2016] [Indexed: 01/10/2023]
Abstract
The intracellular bacterial pathogen Francisella tularensis causes tularemia, a zoonosis that can be fatal. The type VI secretion system (T6SS) encoded by the Francisella pathogenicity island (FPI) is critical for the virulence of this organism. Existing studies suggest that the complete repertoire of T6SS effectors delivered to host cells is encoded by the FPI. Using a proteome-wide approach, we discovered that the FPI-encoded T6SS exports at least three effectors encoded outside of the island. These proteins share features with virulence determinants of other pathogens, and we provide evidence that they can contribute to intramacrophage growth. The remaining proteins that we identified are encoded within the FPI. Two of these FPI-encoded proteins constitute effectors, whereas the others form a unique complex required for core function of the T6SS apparatus. The discovery of secreted effectors mediating interactions between Francisella and its host significantly advances our understanding of the pathogenesis of this organism.
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Affiliation(s)
- Aria Eshraghi
- Department of Microbiology, School of Medicine, University of Washington, Seattle, WA 98195, USA
| | - Jungyun Kim
- Department of Microbiology, School of Medicine, University of Washington, Seattle, WA 98195, USA
| | - Alexandra C Walls
- Department of Biochemistry, School of Medicine, University of Washington, Seattle, WA 98195, USA
| | - Hannah E Ledvina
- Department of Microbiology, School of Medicine, University of Washington, Seattle, WA 98195, USA
| | - Cheryl N Miller
- Paul G. Allen School for Global Animal Health, Washington State University, Pullman, WA 99164, USA
| | - Kathryn M Ramsey
- Division of Infectious Diseases, Boston Children's Hospital, Harvard Medical School, Boston, MA 02115, USA
| | - John C Whitney
- Department of Microbiology, School of Medicine, University of Washington, Seattle, WA 98195, USA
| | - Matthew C Radey
- Department of Microbiology, School of Medicine, University of Washington, Seattle, WA 98195, USA
| | - S Brook Peterson
- Department of Microbiology, School of Medicine, University of Washington, Seattle, WA 98195, USA
| | - Brittany R Ruhland
- Department of Microbiology, School of Medicine, University of Washington, Seattle, WA 98195, USA
| | - Bao Q Tran
- Department of Pharmaceutical Sciences, School of Pharmacy, University of Maryland, Baltimore, MD 21201, USA
| | - Young Ah Goo
- Department of Pharmaceutical Sciences, School of Pharmacy, University of Maryland, Baltimore, MD 21201, USA
| | - David R Goodlett
- Department of Pharmaceutical Sciences, School of Pharmacy, University of Maryland, Baltimore, MD 21201, USA
| | - Simon L Dove
- Division of Infectious Diseases, Boston Children's Hospital, Harvard Medical School, Boston, MA 02115, USA
| | - Jean Celli
- Paul G. Allen School for Global Animal Health, Washington State University, Pullman, WA 99164, USA
| | - David Veesler
- Department of Biochemistry, School of Medicine, University of Washington, Seattle, WA 98195, USA
| | - Joseph D Mougous
- Department of Microbiology, School of Medicine, University of Washington, Seattle, WA 98195, USA; Howard Hughes Medical Institute, School of Medicine, University of Washington, Seattle, WA 98195, USA.
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21
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Abstract
Specialized secretion systems are infamous for their contribution to host-pathogen interactions. Our discovery that the type VI secretion system delivers toxins between bacterial cells has broadened our understanding of how both pathogens and non-pathogens interact with one another, whether within or outside of the host.
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Affiliation(s)
- Rachel D Hood
- Department of Molecular and Cell Biology, University of California, Berkeley, CA 94720, USA
| | - S Brook Peterson
- Department of Microbiology, School of Medicine, University of Washington, Seattle, WA 98195, USA
| | - Joseph D Mougous
- Department of Microbiology, School of Medicine, University of Washington, Seattle, WA 98195, USA; Howard Hughes Medical Institute, School of Medicine, University of Washington, Seattle, WA 98195, USA.
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22
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Whitney JC, Peterson SB, Kim J, Pazos M, Verster AJ, Radey MC, Kulasekara HD, Ching MQ, Bullen NP, Bryant D, Goo YA, Surette MG, Borenstein E, Vollmer W, Mougous JD. A broadly distributed toxin family mediates contact-dependent antagonism between gram-positive bacteria. eLife 2017; 6. [PMID: 28696203 PMCID: PMC5555719 DOI: 10.7554/elife.26938] [Citation(s) in RCA: 99] [Impact Index Per Article: 14.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/20/2017] [Accepted: 07/10/2017] [Indexed: 12/24/2022] Open
Abstract
The Firmicutes are a phylum of bacteria that dominate numerous polymicrobial habitats of importance to human health and industry. Although these communities are often densely colonized, a broadly distributed contact-dependent mechanism of interbacterial antagonism utilized by Firmicutes has not been elucidated. Here we show that proteins belonging to the LXG polymorphic toxin family present in Streptococcus intermedius mediate cell contact- and Esx secretion pathway-dependent growth inhibition of diverse Firmicute species. The structure of one such toxin revealed a previously unobserved protein fold that we demonstrate directs the degradation of a uniquely bacterial molecule required for cell wall biosynthesis, lipid II. Consistent with our functional data linking LXG toxins to interbacterial interactions in S. intermedius, we show that LXG genes are prevalent in the human gut microbiome, a polymicrobial community dominated by Firmicutes. We speculate that interbacterial antagonism mediated by LXG toxins plays a critical role in shaping Firmicute-rich bacterial communities. DOI:http://dx.doi.org/10.7554/eLife.26938.001 Most bacteria live in densely colonized environments, such as the human gut, in which they must constantly compete with other microbes for space and nutrients. As a result, bacteria have evolved a wide array of strategies to directly fight their neighbors. For example, some bacteria release antimicrobial compounds into their surroundings, while others ‘inject’ protein toxins directly into adjacent cells. Bacteria can be classified into two groups known as Gram-positive and Gram-negative. Previous studies found that Gram-negative bacteria inject toxins into neighboring cells, but no comparable toxins in Gram-positive bacteria had been identified. Before a bacterium can inject molecules into an adjacent cell, it needs to move the toxins from its interior to the cell surface. It had been suggested that a transport system in Gram-positive bacteria called the Esx pathway may export toxins known as LXG proteins. However, it was not clear whether these proteins help Gram-positive bacteria to compete against other bacteria. Whitney et al. studied the LXG proteins in Gram-positive bacteria known as Firmicutes. The experiments reveal that Firmicutes found in the human gut possess LXG genes. A Firmicute known as Streptococcus intermedius produces three LXG proteins that are all toxic to bacteria. To avoid being harmed by its own LXG proteins, S. intermedius also produces matching antidote proteins. Further experiments show that LXG proteins are exported out of S. intermedius cells and into adjacent competitor bacteria by the Esx pathway. Examining one of these LXG proteins in more detail showed that it can degrade a molecule that bacteria need to make their cell wall. Together, these findings suggest that LXG proteins may influence the species living in many important microbial communities, including the human gut. Changes in the communities of gut microbes have been linked with many diseases. Therefore, understanding more about how the LXG proteins work may help us to develop ways to manipulate these communities to improve human health. DOI:http://dx.doi.org/10.7554/eLife.26938.002
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Affiliation(s)
- John C Whitney
- Department of Microbiology, University of Washington School of Medicine, Seattle, United States
| | - S Brook Peterson
- Department of Microbiology, University of Washington School of Medicine, Seattle, United States
| | - Jungyun Kim
- Department of Microbiology, University of Washington School of Medicine, Seattle, United States
| | - Manuel Pazos
- Centre for Bacterial Cell Biology, Institute for Cell and Molecular Biosciences, Newcastle University, Newcastle, United Kingdom
| | - Adrian J Verster
- Department of Genome Sciences, University of Washington, Seattle, United States
| | - Matthew C Radey
- Department of Microbiology, University of Washington School of Medicine, Seattle, United States
| | - Hemantha D Kulasekara
- Department of Microbiology, University of Washington School of Medicine, Seattle, United States
| | - Mary Q Ching
- Department of Microbiology, University of Washington School of Medicine, Seattle, United States
| | - Nathan P Bullen
- Michael DeGroote Institute for Infectious Disease Research, McMaster University, Hamilton, Canada.,Department of Biochemistry and Biomedical Sciences, McMaster University, Hamilton, Canada
| | - Diane Bryant
- Experimental Systems Group, Advanced Light Source, Berkeley, United States
| | - Young Ah Goo
- Northwestern Proteomics Core Facility, Northwestern University, Chicago, United States
| | - Michael G Surette
- Michael DeGroote Institute for Infectious Disease Research, McMaster University, Hamilton, Canada.,Department of Biochemistry and Biomedical Sciences, McMaster University, Hamilton, Canada.,Department of Medicine, Farncombe Family Digestive Health Research Institute, McMaster University, Hamilton, Canada
| | - Elhanan Borenstein
- Department of Genome Sciences, University of Washington, Seattle, United States.,Department of Computer Science and Engineering, University of Washington, Seattle, United States.,Santa Fe Institute, Santa Fe, United States
| | - Waldemar Vollmer
- Centre for Bacterial Cell Biology, Institute for Cell and Molecular Biosciences, Newcastle University, Newcastle, United Kingdom
| | - Joseph D Mougous
- Department of Microbiology, University of Washington School of Medicine, Seattle, United States.,Howard Hughes Medical Institute, University of Washington School of Medicine, Seattle, United States
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23
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Whitney JC, Quentin D, Sawai S, LeRoux M, Harding BN, Ledvina HE, Tran BQ, Robinson H, Goo YA, Goodlett DR, Raunser S, Mougous JD. An interbacterial NAD(P)(+) glycohydrolase toxin requires elongation factor Tu for delivery to target cells. Cell 2015; 163:607-19. [PMID: 26456113 DOI: 10.1016/j.cell.2015.09.027] [Citation(s) in RCA: 156] [Impact Index Per Article: 17.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/18/2015] [Revised: 07/15/2015] [Accepted: 08/19/2015] [Indexed: 11/17/2022]
Abstract
Type VI secretion (T6S) influences the composition of microbial communities by catalyzing the delivery of toxins between adjacent bacterial cells. Here, we demonstrate that a T6S integral membrane toxin from Pseudomonas aeruginosa, Tse6, acts on target cells by degrading the universally essential dinucleotides NAD(+) and NADP(+). Structural analyses of Tse6 show that it resembles mono-ADP-ribosyltransferase proteins, such as diphtheria toxin, with the exception of a unique loop that both excludes proteinaceous ADP-ribose acceptors and contributes to hydrolysis. We find that entry of Tse6 into target cells requires its binding to an essential housekeeping protein, translation elongation factor Tu (EF-Tu). These proteins participate in a larger assembly that additionally directs toxin export and provides chaperone activity. Visualization of this complex by electron microscopy defines the architecture of a toxin-loaded T6S apparatus and provides mechanistic insight into intercellular membrane protein delivery between bacteria.
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Affiliation(s)
- John C Whitney
- Department of Microbiology, University of Washington, Seattle, WA 98195, USA
| | - Dennis Quentin
- Department of Structural Biochemistry, Max Planck Institute of Molecular Physiology, Otto-Hahn-Strasse 11, 44227 Dortmund, Germany
| | - Shin Sawai
- Department of Microbiology, University of Washington, Seattle, WA 98195, USA
| | - Michele LeRoux
- Department of Microbiology, University of Washington, Seattle, WA 98195, USA
| | - Brittany N Harding
- Department of Microbiology, University of Washington, Seattle, WA 98195, USA
| | - Hannah E Ledvina
- Department of Microbiology, University of Washington, Seattle, WA 98195, USA
| | - Bao Q Tran
- Department of Pharmaceutical Sciences, School of Pharmacy, University of Maryland, Baltimore, MD 21201, USA
| | - Howard Robinson
- Biology Department, Brookhaven National Laboratory, Upton, NY 11973, USA
| | - Young Ah Goo
- Department of Pharmaceutical Sciences, School of Pharmacy, University of Maryland, Baltimore, MD 21201, USA
| | - David R Goodlett
- Department of Pharmaceutical Sciences, School of Pharmacy, University of Maryland, Baltimore, MD 21201, USA
| | - Stefan Raunser
- Department of Structural Biochemistry, Max Planck Institute of Molecular Physiology, Otto-Hahn-Strasse 11, 44227 Dortmund, Germany
| | - Joseph D Mougous
- Department of Microbiology, University of Washington, Seattle, WA 98195, USA; Howard Hughes Medical Institute, Seattle, WA 98195, USA.
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24
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Abstract
Here we propose that bacteria detect and respond to threats posed by other bacteria via an innate immune-like process that we term danger sensing. We find support for this contention by reexamining existing literature from the perspective that intermicrobial antagonism, not opportunistic pathogenesis, is the major evolutionary force shaping the defensive behaviors of most bacteria. We conclude that many bacteria possess danger sensing pathways composed of a danger signal receptor and corresponding signal transduction mechanism that regulate pathways important for survival in the presence of the perceived competitor.
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Affiliation(s)
- Michele LeRoux
- Department of Microbiology, University of Washington, Seattle, WA 98195, USA; Molecular and Cellular Biology Program, University of Washington, Seattle, WA 98195, USA
| | - S Brook Peterson
- Department of Microbiology, University of Washington, Seattle, WA 98195, USA
| | - Joseph D Mougous
- Department of Microbiology, University of Washington, Seattle, WA 98195, USA; Howard Hughes Medical Institute, Seattle, WA 98195, USA.
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25
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LeRoux M, Kirkpatrick RL, Montauti EI, Tran BQ, Peterson SB, Harding BN, Whitney JC, Russell AB, Traxler B, Goo YA, Goodlett DR, Wiggins PA, Mougous JD. Kin cell lysis is a danger signal that activates antibacterial pathways of Pseudomonas aeruginosa. eLife 2015; 4. [PMID: 25643398 PMCID: PMC4348357 DOI: 10.7554/elife.05701] [Citation(s) in RCA: 85] [Impact Index Per Article: 9.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/20/2014] [Accepted: 01/30/2015] [Indexed: 12/21/2022] Open
Abstract
The perception and response to cellular death is an important aspect of multicellular eukaryotic life. For example, damage-associated molecular patterns activate an inflammatory cascade that leads to removal of cellular debris and promotion of healing. We demonstrate that lysis of Pseudomonas aeruginosa cells triggers a program in the remaining population that confers fitness in interspecies co-culture. We find that this program, termed P. aeruginosa response to antagonism (PARA), involves rapid deployment of antibacterial factors and is mediated by the Gac/Rsm global regulatory pathway. Type VI secretion, and, unexpectedly, conjugative type IV secretion within competing bacteria, induce P. aeruginosa lysis and activate PARA, thus providing a mechanism for the enhanced capacity of P. aeruginosa to target bacteria that elaborate these factors. Our finding that bacteria sense damaged kin and respond via a widely distributed pathway to mount a complex response raises the possibility that danger sensing is an evolutionarily conserved process. DOI:http://dx.doi.org/10.7554/eLife.05701.001 Bacteria live in diverse and changing environments where resources such as nutrients and space are often limited. They have thus evolved many survival strategies, including competitive and cooperative behaviors. In the first case, bacteria antagonize or prevent the growth of other microorganisms competing with them for resources, such as by generating antibiotics that specifically target rivals. During cooperation, bacteria may coordinate the production of compounds that have a shared benefit for members of their community. In multicellular organisms, some cell types sense harmful microorganisms by the injury they cause in neighboring cells. This triggers a process that can lead to the production of molecules that kill the invaders and factors that promote the repair of cellular damage. An equivalent process has so far not been described for single-celled organisms such as bacteria. However, bacteria often live in structured groups containing many different species. In this type of growth environment, the ability of bacteria to sense when others of their species are attacked and to respond by taking measures to defend themselves could improve their chances of survival. Now, LeRoux et al. reveal that the bacterium Pseudomonas aeruginosa is able to detect ‘danger signals’ released when neighboring P. aeruginosa cells are killed by other bacteria. These signals trigger a response in surviving cells by turning on a pathway that controls a number of antibacterial factors. These include the production of the so-called ‘type VI secretion system’, a molecular machine that delivers a potent cocktail of antibacterial toxins directly into nearby bacteria. This process, which LeRoux et al. have named ‘P. aeruginosa response to antagonism’, or PARA for short, enables P. aeruginosa to thrive when grown with competing bacterial species. P. aeruginosa is notorious for infecting the lungs of people with the genetic disease cystic fibrosis, as well as chronic wounds often found in people with diabetes. In both cases, when P. aeruginosa is present, the numbers of other, often less harmful organisms, tend to decrease. PARA may be one reason for the success of P. aeruginosa in these multi-species infections. DOI:http://dx.doi.org/10.7554/eLife.05701.002
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Affiliation(s)
- Michele LeRoux
- Department of Microbiology, University of Washington, Seattle, United States
| | - Robin L Kirkpatrick
- Department of Microbiology, University of Washington, Seattle, United States
| | - Elena I Montauti
- Department of Microbiology, University of Washington, Seattle, United States
| | - Bao Q Tran
- Department of Pharmaceutical Sciences, School of Pharmacy, University of Maryland, Baltimore, United States
| | - S Brook Peterson
- Department of Microbiology, University of Washington, Seattle, United States
| | - Brittany N Harding
- Department of Microbiology, University of Washington, Seattle, United States
| | - John C Whitney
- Department of Microbiology, University of Washington, Seattle, United States
| | - Alistair B Russell
- Department of Microbiology, University of Washington, Seattle, United States
| | - Beth Traxler
- Department of Microbiology, University of Washington, Seattle, United States
| | - Young Ah Goo
- Department of Pharmaceutical Sciences, School of Pharmacy, University of Maryland, Baltimore, United States
| | - David R Goodlett
- Department of Pharmaceutical Sciences, School of Pharmacy, University of Maryland, Baltimore, United States
| | - Paul A Wiggins
- Department of Physics, University of Washington, Seattle, United States
| | - Joseph D Mougous
- Department of Microbiology, University of Washington, Seattle, United States
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26
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Russell AB, Wexler AG, Harding BN, Whitney JC, Bohn AJ, Goo YA, Tran BQ, Barry NA, Zheng H, Peterson SB, Chou S, Gonen T, Goodlett DR, Goodman AL, Mougous JD. A type VI secretion-related pathway in Bacteroidetes mediates interbacterial antagonism. Cell Host Microbe 2014; 16:227-236. [PMID: 25070807 DOI: 10.1016/j.chom.2014.07.007] [Citation(s) in RCA: 241] [Impact Index Per Article: 24.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/12/2014] [Revised: 07/04/2014] [Accepted: 07/09/2014] [Indexed: 12/12/2022]
Abstract
Bacteroidetes are a phylum of Gram-negative bacteria abundant in mammalian-associated polymicrobial communities, where they impact digestion, immunity, and resistance to infection. Despite the extensive competition at high cell density that occurs in these settings, cell contact-dependent mechanisms of interbacterial antagonism, such as the type VI secretion system (T6SS), have not been defined in this group of organisms. Herein we report the bioinformatic and functional characterization of a T6SS-like pathway in diverse Bacteroidetes. Using prominent human gut commensal and soil-associated species, we demonstrate that these systems localize dynamically within the cell, export antibacterial proteins, and target competitor bacteria. The Bacteroidetes system is a distinct pathway with marked differences in gene content and high evolutionary divergence from the canonical T6S pathway. Our findings offer a potential molecular explanation for the abundance of Bacteroidetes in polymicrobial environments, the observed stability of Bacteroidetes in healthy humans, and the barrier presented by the microbiota against pathogens.
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Affiliation(s)
- Alistair B Russell
- Department of Microbiology, University of Washington, Seattle, WA 98195, USA
| | - Aaron G Wexler
- Department of Microbial Pathogenesis and Microbial Diversity Institute, Yale University School of Medicine, New Haven, CT 06536, USA
| | - Brittany N Harding
- Department of Microbiology, University of Washington, Seattle, WA 98195, USA
| | - John C Whitney
- Department of Microbiology, University of Washington, Seattle, WA 98195, USA
| | - Alan J Bohn
- Department of Microbiology, University of Washington, Seattle, WA 98195, USA
| | - Young Ah Goo
- Department of Pharmaceutical Sciences, School of Pharmacy, University of Maryland, Baltimore, MD 21201, USA
| | - Bao Q Tran
- Department of Pharmaceutical Sciences, School of Pharmacy, University of Maryland, Baltimore, MD 21201, USA
| | - Natasha A Barry
- Department of Microbial Pathogenesis and Microbial Diversity Institute, Yale University School of Medicine, New Haven, CT 06536, USA
| | - Hongjin Zheng
- Janelia Research Campus, Howard Hughes Medical Institute, Ashburn, VA 20147, USA
| | - S Brook Peterson
- Department of Microbiology, University of Washington, Seattle, WA 98195, USA
| | - Seemay Chou
- Department of Microbiology, University of Washington, Seattle, WA 98195, USA
| | - Tamir Gonen
- Janelia Research Campus, Howard Hughes Medical Institute, Ashburn, VA 20147, USA
| | - David R Goodlett
- Department of Pharmaceutical Sciences, School of Pharmacy, University of Maryland, Baltimore, MD 21201, USA
| | - Andrew L Goodman
- Department of Microbial Pathogenesis and Microbial Diversity Institute, Yale University School of Medicine, New Haven, CT 06536, USA.
| | - Joseph D Mougous
- Department of Microbiology, University of Washington, Seattle, WA 98195, USA.
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27
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Whitney JC, Beck CM, Goo YA, Russell AB, Harding BN, De Leon JA, Cunningham DA, Tran BQ, Low DA, Goodlett DR, Hayes CS, Mougous JD. Genetically distinct pathways guide effector export through the type VI secretion system. Mol Microbiol 2014; 92:529-42. [PMID: 24589350 DOI: 10.1111/mmi.12571] [Citation(s) in RCA: 139] [Impact Index Per Article: 13.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 02/28/2014] [Indexed: 12/01/2022]
Abstract
Bacterial secretion systems often employ molecular chaperones to recognize and facilitate export of their substrates. Recent work demonstrated that a secreted component of the type VI secretion system (T6SS), haemolysin co-regulated protein (Hcp), binds directly to effectors, enhancing their stability in the bacterial cytoplasm. Herein, we describe a quantitative cellular proteomics screen for T6S substrates that exploits this chaperone-like quality of Hcp. Application of this approach to the Hcp secretion island I-encoded T6SS (H1-T6SS) of Pseudomonas aeruginosa led to the identification of a novel effector protein, termed Tse4 (type VI secretion exported 4), subsequently shown to act as a potent intra-specific H1-T6SS-delivered antibacterial toxin. Interestingly, our screen failed to identify two predicted H1-T6SS effectors, Tse5 and Tse6, which differ from Hcp-stabilized substrates by the presence of toxin-associated PAAR-repeat motifs and genetic linkage to members of the valine-glycine repeat protein G (vgrG) genes. Genetic studies further distinguished these two groups of effectors: Hcp-stabilized effectors were found to display redundancy in interbacterial competition with respect to the requirement for the two H1-T6SS-exported VgrG proteins, whereas Tse5 and Tse6 delivery strictly required a cognate VgrG. Together, we propose that interaction with either VgrG or Hcp defines distinct pathways for T6S effector export.
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Affiliation(s)
- John C Whitney
- Department of Microbiology, University of Washington, Seattle, WA, 98195, USA
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28
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Abstract
The type VI secretion system (T6SS) mediates interactions between a broad range of Gram-negative bacterial species. Recent studies have led to a substantial increase in the number of characterized T6SS effector proteins and a more complete and nuanced view of the adaptive importance of the system. Although the T6SS is most often implicated in antagonism, in this Review, we consider the case for its involvement in both antagonistic and non-antagonistic behaviours. Clarifying the roles that type VI secretion has in microbial communities will contribute to broader efforts to understand the importance of microbial interactions in maintaining human and environmental health, and will inform efforts to manipulate these interactions for therapeutic or environmental benefit.
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Affiliation(s)
- Alistair B Russell
- Department of Microbiology, University of Washington, Seattle, Washington 98195, USA
| | - S Brook Peterson
- Department of Microbiology, University of Washington, Seattle, Washington 98195, USA
| | - Joseph D Mougous
- Department of Microbiology, University of Washington, Seattle, Washington 98195, USA
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29
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Silverman JM, Agnello DM, Zheng H, Andrews BT, Li M, Catalano CE, Gonen T, Mougous JD. Haemolysin coregulated protein is an exported receptor and chaperone of type VI secretion substrates. Mol Cell 2013; 51:584-93. [PMID: 23954347 DOI: 10.1016/j.molcel.2013.07.025] [Citation(s) in RCA: 201] [Impact Index Per Article: 18.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/28/2013] [Revised: 06/27/2013] [Accepted: 07/25/2013] [Indexed: 10/26/2022]
Abstract
Secretion systems require high-fidelity mechanisms to discriminate substrates among the vast cytoplasmic pool of proteins. Factors mediating substrate recognition by the type VI secretion system (T6SS) of Gram-negative bacteria, a widespread pathway that translocates effector proteins into target bacterial cells, have not been defined. We report that haemolysin coregulated protein (Hcp), a ring-shaped hexamer secreted by all characterized T6SSs, binds specifically to cognate effector molecules. Electron microscopy analysis of an Hcp-effector complex from Pseudomonas aeruginosa revealed the effector bound to the inner surface of Hcp. Further studies demonstrated that interaction with the Hcp pore is a general requirement for secretion of diverse effectors encompassing several enzymatic classes. Though previous models depict Hcp as a static conduit, our data indicate it is a chaperone and receptor of substrates. These unique functions of a secreted protein highlight fundamental differences between the export mechanism of T6 and other characterized secretory pathways.
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Affiliation(s)
- Julie M Silverman
- Department of Microbiology, University of Washington, Seattle, WA 98195, USA
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30
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Whitney JC, Chou S, Russell AB, Biboy J, Gardiner TE, Ferrin MA, Brittnacher M, Vollmer W, Mougous JD. Identification, structure, and function of a novel type VI secretion peptidoglycan glycoside hydrolase effector-immunity pair. J Biol Chem 2013; 288:26616-24. [PMID: 23878199 DOI: 10.1074/jbc.m113.488320] [Citation(s) in RCA: 89] [Impact Index Per Article: 8.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Bacteria employ type VI secretion systems (T6SSs) to facilitate interactions with prokaryotic and eukaryotic cells. Despite the widespread identification of T6SSs among Gram-negative bacteria, the number of experimentally validated substrate effector proteins mediating these interactions remains small. Here, employing an informatics approach, we define novel families of T6S peptidoglycan glycoside hydrolase effectors. Consistent with the known intercellular self-intoxication exhibited by the T6S pathway, we observe that each effector gene is located adjacent to a hypothetical open reading frame encoding a putative periplasmically localized immunity determinant. To validate our sequence-based approach, we functionally investigate a representative family member from the soil-dwelling bacterium Pseudomonas protegens. We demonstrate that this protein is secreted in a T6SS-dependent manner and that it confers a fitness advantage in growth competition assays with Pseudomonas putida. In addition, we determined the 1.4 Å x-ray crystal structure of this effector in complex with its cognate immunity protein. The structure reveals the effector shares highest overall structural similarity to a glycoside hydrolase family associated with peptidoglycan N-acetylglucosaminidase activity, suggesting that T6S peptidoglycan glycoside hydrolase effector families may comprise significant enzymatic diversity. Our structural analyses also demonstrate that self-intoxication is prevented by the immunity protein through direct occlusion of the effector active site. This work significantly expands our current understanding of T6S effector diversity.
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Russell AB, LeRoux M, Hathazi K, Agnello DM, Ishikawa T, Wiggins PA, Wai SN, Mougous JD. Diverse type VI secretion phospholipases are functionally plastic antibacterial effectors. Nature 2013; 496:508-12. [PMID: 23552891 PMCID: PMC3652678 DOI: 10.1038/nature12074] [Citation(s) in RCA: 268] [Impact Index Per Article: 24.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/16/2013] [Accepted: 03/15/2013] [Indexed: 11/17/2022]
Abstract
Membranes allow the compartmentalization of biochemical processes and are therefore fundamental to life. The conservation of the cellular membrane, combined with its accessibility to secreted proteins, has made it a common target of factors mediating antagonistic interactions between diverse organisms. Here we report the discovery of a diverse superfamily of bacterial phospholipase enzymes. Within this superfamily, we defined enzymes with phospholipase A1 (PLA1) and A2 (PLA2) activity, which are common in host cell-targeting bacterial toxins and the venoms of certain insects and reptiles1,2. However, we find that the fundamental role of the superfamily is to mediate antagonistic bacterial interactions as effectors of the type VI secretion system (T6SS) translocation apparatus; accordingly, we name these proteins type VI lipase effectors (Tle). Our analyses indicate that PldA of Pseudomonas aeruginosa, a eukaryotic-like phospholipase D (PLD)3, is a member of the Tle superfamily and the founding substrate of the haemolysin co-regulated protein secretion island II T6SS (H2-T6SS). While prior studies have specifically implicated PldA and the H2-T6SS in pathogenesis3–5, we uncovered a specific role for the effector and its secretory machinery in intra- and inter-species bacterial interactions. Furthermore we find that this effector achieves its antibacterial activity by degrading phosphatidylethanolamine (PE), the major component of bacterial membranes. The surprising finding that virulence-associated phospholipases can serve as specific antibacterial effectors suggests that interbacterial interactions are a relevant factor driving the ongoing evolution of pathogenesis.
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Affiliation(s)
- Alistair B Russell
- Department of Microbiology, University of Washington, Seattle, Washington 98195, USA
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Russell AB, Singh P, Brittnacher M, Bui NK, Hood RD, Carl MA, Agnello DM, Schwarz S, Goodlett DR, Vollmer W, Mougous JD. A widespread bacterial type VI secretion effector superfamily identified using a heuristic approach. Cell Host Microbe 2012; 11:538-49. [PMID: 22607806 DOI: 10.1016/j.chom.2012.04.007] [Citation(s) in RCA: 182] [Impact Index Per Article: 15.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/06/2012] [Revised: 03/20/2012] [Accepted: 04/10/2012] [Indexed: 01/15/2023]
Abstract
Sophisticated mechanisms are employed to facilitate information exchange between interfacing bacteria. A type VI secretion system (T6SS) of Pseudomonas aeruginosa was shown to deliver cell wall-targeting effectors to neighboring cells. However, the generality of bacteriolytic effectors and, moreover, of antibacterial T6S remained unknown. Using parameters derived from experimentally validated bacterial T6SS effectors we identified a phylogenetically disperse superfamily of T6SS-associated peptidoglycan-degrading effectors. The effectors separate into four families composed of peptidoglycan amidase enzymes of differing specificities. Effectors strictly co-occur with cognate immunity proteins, indicating that self-intoxication is a general property of antibacterial T6SSs and effector delivery by the system exerts a strong selective pressure in nature. The presence of antibacterial effectors in a plethora of organisms, including many that inhabit or infect polymicrobial niches in the human body, suggests that the system could mediate interbacterial interactions of both environmental and clinical significance.
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Affiliation(s)
- Alistair B Russell
- Department of Microbiology, University of Washington, Seattle, WA 98195, USA
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33
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Casabona MG, Silverman JM, Sall KM, Boyer F, Couté Y, Poirel J, Grunwald D, Mougous JD, Elsen S, Attree I. An ABC transporter and an outer membrane lipoprotein participate in posttranslational activation of type VI secretion in Pseudomonas aeruginosa. Environ Microbiol 2012; 15:471-86. [PMID: 22765374 DOI: 10.1111/j.1462-2920.2012.02816.x] [Citation(s) in RCA: 70] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023]
Abstract
Pseudomonas aeruginosa is capable of injecting protein toxins into other bacterial cells through one of its three type VI secretion systems (T6SSs). The activity of this T6SS is tightly regulated on the posttranslational level by phosphorylation-dependent and -independent pathways. The phosphorylation-dependent pathway consists of a Threonine kinase/phosphatase pair (PpkA/PppA) that acts on a forkhead domain-containing protein, Fha1, and a periplasmic protein, TagR, that positively regulates PpkA. In the present work, we biochemically and functionally characterize three additional proteins of the phosphorylation-dependent regulatory cascade that controls T6S activation: TagT, TagS and TagQ. We show that similar to TagR, these proteins act upstream of the PpkA/PppA checkpoint and influence phosphorylation of Fha1 and, apparatus assembly and effector export. Localization studies demonstrate that TagQ is an outer membrane lipoprotein and TagR is associated with the outer membrane. Consistent with their homology to lipoprotein outer membrane localization (Lol) components, TagT and TagS form a stable inner membrane complex with ATPase activity. However, we find that outer membrane association of T6SS lipoproteins TagQ and TssJ1, and TagR, is unaltered in a ΔtagTS background. Notably, we found that TagQ is indispensible for anchoring of TagR to the outer membrane fraction. As T6S-dependent fitness of P. aeruginosa requires TagT, S, R and Q, we conclude that these proteins likely participate in a trans-membrane signalling pathway that promotes H1-T6SS activity under optimal environmental conditions.
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Affiliation(s)
- Maria G Casabona
- INSERM, UMR-S 1036, Biology of Cancer and Infection, Grenoble, France
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Abstract
The type VI secretion system (T6SS) is a complex and widespread gram-negative bacterial export pathway with the capacity to translocate protein effectors into a diversity of target cell types. Current structural models of the T6SS indicate that the apparatus is composed of at least two complexes, a dynamic bacteriophage-like structure and a cell-envelope-spanning membrane-associated assembly. How these complexes interact to promote effector secretion and cell targeting remains a major question in the field. As a contact-dependent pathway with specific cellular targets, the T6SS is subject to tight regulation. Thus, the identification of regulatory elements that control T6S expression continues to shape our understanding of the environmental circumstances relevant to its function. This review discusses recent progress toward characterizing T6S structure and regulation.
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Affiliation(s)
- Julie M Silverman
- Department of Microbiology, University of Washington, Seattle, 98195, USA
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35
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Chou S, Bui NK, Russell AB, Lexa KW, Gardiner TE, LeRoux M, Vollmer W, Mougous JD. Structure of a peptidoglycan amidase effector targeted to Gram-negative bacteria by the type VI secretion system. Cell Rep 2012; 1:656-64. [PMID: 22813741 DOI: 10.1016/j.celrep.2012.05.016] [Citation(s) in RCA: 64] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/17/2012] [Revised: 05/11/2012] [Accepted: 05/21/2012] [Indexed: 12/21/2022] Open
Abstract
The target range of a bacterial secretion system can be defined by effector substrate specificity or by the efficacy of effector delivery. Here, we report the crystal structure of Tse1, a type VI secretion (T6S) bacteriolytic amidase effector from Pseudomonas aeruginosa. Consistent with its role as a toxin, Tse1 has a more accessible active site than related housekeeping enzymes. The activity of Tse1 against isolated peptidoglycan shows its capacity to act broadly against Gram-negative bacteria and even certain Gram-positive species. Studies with intact cells indicate that Gram-positive bacteria can remain vulnerable to Tse1 despite cell wall modifications. However, interbacterial competition studies demonstrate that Tse1-dependent lysis is restricted to Gram-negative targets. We propose that the previously observed specificity for T6S against Gram-negative bacteria is a consequence of high local effector concentration achieved by T6S-dependent targeting to its site of action rather than inherent effector substrate specificity.
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Affiliation(s)
- Seemay Chou
- Department of Microbiology, University of Washington, Seattle, WA 98195, USA
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Silverman JM, Austin LS, Hsu F, Hicks KG, Hood RD, Mougous JD. Separate inputs modulate phosphorylation-dependent and -independent type VI secretion activation. Mol Microbiol 2011; 82:1277-90. [PMID: 22017253 DOI: 10.1111/j.1365-2958.2011.07889.x] [Citation(s) in RCA: 80] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
Productive intercellular delivery of cargo by secretory systems requires exquisite temporal and spatial choreography. Our laboratory has demonstrated that the haemolysin co-regulated secretion island I (HSI-I)-encoded type VI secretion system (H1-T6SS) of Pseudomonas aeruginosa transfers effector proteins to other bacterial cells. The activity of these effectors requires cell contact-dependent delivery by the secretion apparatus, and thus their export is highly repressed under planktonic growth conditions. Here we define regulatory pathways that orchestrate efficient secretion by this system. We identified a T6S-associated protein, TagF, as a posttranslational repressor of the H1-T6SS. Strains activated by TagF derepression or stimulated through a previously identified threonine phosphorylation pathway (TPP) share the property of secretory ATPase recruitment to the T6S apparatus, yet display different effector output levels and genetic requirements for their export. We also found that these two pathways respond to distinct stimuli; we identified surface growth as a physiological cue that activates the H1-T6SS exclusively through the TPP. Coordination of posttranslational triggering with cell contact-promoting growth conditions provides a mechanism for the T6SS to avoid wasteful release of effectors.
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Affiliation(s)
- Julie M Silverman
- Department of Microbiology, University of Washington, Seattle, WA 98195, USA
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Schwarz S, West TE, Boyer F, Chiang WC, Carl MA, Hood RD, Rohmer L, Tolker-Nielsen T, Skerrett SJ, Mougous JD. Burkholderia type VI secretion systems have distinct roles in eukaryotic and bacterial cell interactions. PLoS Pathog 2010; 6:e1001068. [PMID: 20865170 PMCID: PMC2928800 DOI: 10.1371/journal.ppat.1001068] [Citation(s) in RCA: 291] [Impact Index Per Article: 20.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/03/2010] [Accepted: 07/26/2010] [Indexed: 12/01/2022] Open
Abstract
Bacteria that live in the environment have evolved pathways specialized to defend against eukaryotic organisms or other bacteria. In this manuscript, we systematically examined the role of the five type VI secretion systems (T6SSs) of Burkholderia thailandensis (B. thai) in eukaryotic and bacterial cell interactions. Consistent with phylogenetic analyses comparing the distribution of the B. thai T6SSs with well-characterized bacterial and eukaryotic cell-targeting T6SSs, we found that T6SS-5 plays a critical role in the virulence of the organism in a murine melioidosis model, while a strain lacking the other four T6SSs remained as virulent as the wild-type. The function of T6SS-5 appeared to be specialized to the host and not related to an in vivo growth defect, as ΔT6SS-5 was fully virulent in mice lacking MyD88. Next we probed the role of the five systems in interbacterial interactions. From a group of 31 diverse bacteria, we identified several organisms that competed less effectively against wild-type B. thai than a strain lacking T6SS-1 function. Inactivation of T6SS-1 renders B. thai greatly more susceptible to cell contact-induced stasis by Pseudomonas putida, Pseudomonas fluorescens and Serratia proteamaculans—leaving it 100- to 1000-fold less fit than the wild-type in competition experiments with these organisms. Flow cell biofilm assays showed that T6S-dependent interbacterial interactions are likely relevant in the environment. B. thai cells lacking T6SS-1 were rapidly displaced in mixed biofilms with P. putida, whereas wild-type cells persisted and overran the competitor. Our data show that T6SSs within a single organism can have distinct functions in eukaryotic versus bacterial cell interactions. These systems are likely to be a decisive factor in the survival of bacterial cells of one species in intimate association with those of another, such as in polymicrobial communities present both in the environment and in many infections. Many bacteria encounter both eukaryotic cells and other bacterial species as a part of their lifestyles. In order to compete and survive, these bacteria have evolved specialized pathways that target these distinct cell types. Type VI secretion systems (T6SSs) are bacterial protein export machines postulated to puncture targeted cells using an apparatus that shares structural similarity to bacteriophage. We investigated the role of the five T6SSs of Burkholderia thailandensis in the defense of the organism against other bacteria and higher organisms. B. thailandensis is a relatively avirulent soil saprophyte that is closely related to the human pathogen B. pseudomallei. Our work uncovered roles for two B. thailandensis T6SSs with specialized functions either in the survival of the organism in a murine host, or against another bacterial cell. We also found that B. thailandensis lacking the bacterial-targeting T6SS could not persist in a mixed biofilm with a competing bacterium. Based on the evolutionary relationship of T6SSs, and our findings that B. thailandensis engages other bacterial species in a T6S-dependent manner, we speculate that this pathway is of general significance to interbacterial interactions in polymicrobial human diseases and the environment.
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Affiliation(s)
- Sandra Schwarz
- Department of Microbiology, University of Washington, Seattle, Washington, United States of America
| | - T. Eoin West
- Department of Medicine, University of Washington, Seattle, Washington, United States of America
| | - Frédéric Boyer
- UMR754 INRA-ENVL-UCBL-EPHE “Rétrovirus et Pathologie Comparée”, IFR 128 BioSciences Lyon-Gerland, Université Claude Bernard Lyon 1, Lyon, France
| | - Wen-Chi Chiang
- Department of International Health, Immunology and Microbiology, University of Copenhagen, Copenhagen, Denmark
| | - Mike A. Carl
- Department of Microbiology, University of Washington, Seattle, Washington, United States of America
| | - Rachel D. Hood
- Department of Microbiology, University of Washington, Seattle, Washington, United States of America
| | - Laurence Rohmer
- Department of Immunology, University of Washington, Seattle, Washington, United States of America
| | - Tim Tolker-Nielsen
- Department of International Health, Immunology and Microbiology, University of Copenhagen, Copenhagen, Denmark
| | - Shawn J. Skerrett
- Department of Medicine, University of Washington, Seattle, Washington, United States of America
| | - Joseph D. Mougous
- Department of Microbiology, University of Washington, Seattle, Washington, United States of America
- * E-mail:
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Hood RD, Singh P, Hsu F, Güvener T, Carl MA, Trinidad RRS, Silverman JM, Ohlson BB, Hicks KG, Plemel RL, Li M, Schwarz S, Wang WY, Merz AJ, Goodlett DR, Mougous JD. A type VI secretion system of Pseudomonas aeruginosa targets a toxin to bacteria. Cell Host Microbe 2010; 7:25-37. [PMID: 20114026 DOI: 10.1016/j.chom.2009.12.007] [Citation(s) in RCA: 643] [Impact Index Per Article: 45.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2009] [Revised: 11/06/2009] [Accepted: 12/18/2009] [Indexed: 12/20/2022]
Abstract
The functional spectrum of a secretion system is defined by its substrates. Here we analyzed the secretomes of Pseudomonas aeruginosa mutants altered in regulation of the Hcp Secretion Island-I-encoded type VI secretion system (H1-T6SS). We identified three substrates of this system, proteins Tse1-3 (type six exported 1-3), which are coregulated with the secretory apparatus and secreted under tight posttranslational control. The Tse2 protein was found to be the toxin component of a toxin-immunity system and to arrest the growth of prokaryotic and eukaryotic cells when expressed intracellularly. In contrast, secreted Tse2 had no effect on eukaryotic cells; however, it provided a major growth advantage for P. aeruginosa strains, relative to those lacking immunity, in a manner dependent on cell contact and the H1-T6SS. This demonstration that the T6SS targets a toxin to bacteria helps reconcile the structural and evolutionary relationship between the T6SS and the bacteriophage tail and spike.
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Affiliation(s)
- Rachel D Hood
- Department of Microbiology, University of Washington, Seattle, WA 98195, USA
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Abstract
Recently a number of nonnatural prenyl groups containing alkynes and azides have been developed as handles to perform click chemistry on proteins and peptides ending in the sequence "CAAX", where C is a cysteine that becomes alkylated, A is an aliphatic amino acid and X is any amino acid. When such molecules are modified, a tag containing a prenyl analogue and the "CAAX box" sequence remains. Here we report the synthesis of an alkyne-containing substrate comprised of only nine nonhydrogen atoms. This substrate was synthesized in six steps from 3-methylbut-2-en-1-ol and has been enzymatically incorporated into both proteins and peptides by using protein farnesyltransferase. After prenylation the final three amino acids required for enzymatic recognition can be removed by using carboxypeptidase Y, leaving a single residue (the cysteine from the "CAAX box") and the prenyl analogue as the only modifications. We also demonstrate that this small tag minimizes the impact of the modification on the solubility of the targeted protein. Hence, this new approach should be useful for applications in which the presence of a large tag hinders the modified protein's solubility, reactivity, or utility.
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Affiliation(s)
- James W Wollack
- Department of Chemistry, University of Minnesota, Minneapolis, 55455, USA
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40
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Yang JC, Madupu R, Durkin AS, Ekborg NA, Pedamallu CS, Hostetler JB, Radune D, Toms BS, Henrissat B, Coutinho PM, Schwarz S, Field L, Trindade-Silva AE, Soares CAG, Elshahawi S, Hanora A, Schmidt EW, Haygood MG, Posfai J, Benner J, Madinger C, Nove J, Anton B, Chaudhary K, Foster J, Holman A, Kumar S, Lessard PA, Luyten YA, Slatko B, Wood N, Wu B, Teplitski M, Mougous JD, Ward N, Eisen JA, Badger JH, Distel DL. The complete genome of Teredinibacter turnerae T7901: an intracellular endosymbiont of marine wood-boring bivalves (shipworms). PLoS One 2009; 4:e6085. [PMID: 19568419 PMCID: PMC2699552 DOI: 10.1371/journal.pone.0006085] [Citation(s) in RCA: 76] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/27/2009] [Accepted: 05/06/2009] [Indexed: 12/02/2022] Open
Abstract
Here we report the complete genome sequence of Teredinibacter turnerae T7901. T. turnerae is a marine gamma proteobacterium that occurs as an intracellular endosymbiont in the gills of wood-boring marine bivalves of the family Teredinidae (shipworms). This species is the sole cultivated member of an endosymbiotic consortium thought to provide the host with enzymes, including cellulases and nitrogenase, critical for digestion of wood and supplementation of the host's nitrogen-deficient diet. T. turnerae is closely related to the free-living marine polysaccharide degrading bacterium Saccharophagus degradans str. 2–40 and to as yet uncultivated endosymbionts with which it coexists in shipworm cells. Like S. degradans, the T. turnerae genome encodes a large number of enzymes predicted to be involved in complex polysaccharide degradation (>100). However, unlike S. degradans, which degrades a broad spectrum (>10 classes) of complex plant, fungal and algal polysaccharides, T. turnerae primarily encodes enzymes associated with deconstruction of terrestrial woody plant material. Also unlike S. degradans and many other eubacteria, T. turnerae dedicates a large proportion of its genome to genes predicted to function in secondary metabolism. Despite its intracellular niche, the T. turnerae genome lacks many features associated with obligate intracellular existence (e.g. reduced genome size, reduced %G+C, loss of genes of core metabolism) and displays evidence of adaptations common to free-living bacteria (e.g. defense against bacteriophage infection). These results suggest that T. turnerae is likely a facultative intracellular ensosymbiont whose niche presently includes, or recently included, free-living existence. As such, the T. turnerae genome provides insights into the range of genomic adaptations associated with intracellular endosymbiosis as well as enzymatic mechanisms relevant to the recycling of plant materials in marine environments and the production of cellulose-derived biofuels.
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Affiliation(s)
- Joyce C. Yang
- Ocean Genome Legacy, Inc., Ipswich, Massachusetts, United States of America
| | - Ramana Madupu
- J. Craig Venter Institute, San Diego, California, United States of America
| | - A. Scott Durkin
- J. Craig Venter Institute, San Diego, California, United States of America
| | - Nathan A. Ekborg
- Ocean Genome Legacy, Inc., Ipswich, Massachusetts, United States of America
| | | | | | - Diana Radune
- J. Craig Venter Institute, San Diego, California, United States of America
| | - Bradley S. Toms
- J. Craig Venter Institute, San Diego, California, United States of America
| | - Bernard Henrissat
- Architecture et Fonction des Macromolécules Biologiques, UMR6098, CNRS, Universités Aix-Marseille I & II, Case 932, Marseille, France
| | - Pedro M. Coutinho
- Architecture et Fonction des Macromolécules Biologiques, UMR6098, CNRS, Universités Aix-Marseille I & II, Case 932, Marseille, France
| | - Sandra Schwarz
- Department of Microbiology, University of Washington, Seattle, Washington, United States of America
| | - Lauren Field
- New England Biolabs, Ipswich, Massachusetts, United States of America
| | - Amaro E. Trindade-Silva
- Universidade Federal do Rio de Janeiro, Instituto de Biologia, Ilha do Fundao, CCS, Rio de Janeiro, Rio de Janeiro, Brazil
| | - Carlos A. G. Soares
- Universidade Federal do Rio de Janeiro, Instituto de Biologia, Ilha do Fundao, CCS, Rio de Janeiro, Rio de Janeiro, Brazil
| | - Sherif Elshahawi
- Department of Environmental and Biomolecular Systems, OGI School of Science & Engineering, Oregon Health & Science University, Beaverton, Oregon, United States of America
| | - Amro Hanora
- Department of Microbiology and Immunology, Faculty of Pharmacy, Suez Canal University, Ismailia, Egypt
| | - Eric W. Schmidt
- College of Pharmacy, University of Utah, Salt Lake City, Utah, United States of America
| | - Margo G. Haygood
- Department of Environmental and Biomolecular Systems, OGI School of Science & Engineering, Oregon Health & Science University, Beaverton, Oregon, United States of America
| | - Janos Posfai
- New England Biolabs, Ipswich, Massachusetts, United States of America
| | - Jack Benner
- New England Biolabs, Ipswich, Massachusetts, United States of America
| | | | - John Nove
- Ocean Genome Legacy, Inc., Ipswich, Massachusetts, United States of America
| | - Brian Anton
- New England Biolabs, Ipswich, Massachusetts, United States of America
| | - Kshitiz Chaudhary
- New England Biolabs, Ipswich, Massachusetts, United States of America
| | - Jeremy Foster
- New England Biolabs, Ipswich, Massachusetts, United States of America
| | - Alex Holman
- New England Biolabs, Ipswich, Massachusetts, United States of America
| | - Sanjay Kumar
- New England Biolabs, Ipswich, Massachusetts, United States of America
| | - Philip A. Lessard
- Massachusetts Institute of Technology, Cambridge, Massachusetts, United States of America
| | - Yvette A. Luyten
- Ocean Genome Legacy, Inc., Ipswich, Massachusetts, United States of America
- New England Biolabs, Ipswich, Massachusetts, United States of America
| | - Barton Slatko
- New England Biolabs, Ipswich, Massachusetts, United States of America
| | - Nicole Wood
- Ocean Genome Legacy, Inc., Ipswich, Massachusetts, United States of America
| | - Bo Wu
- New England Biolabs, Ipswich, Massachusetts, United States of America
| | - Max Teplitski
- University of Florida, Gainesville, Florida, United States of America
| | - Joseph D. Mougous
- Department of Microbiology, University of Washington, Seattle, Washington, United States of America
| | - Naomi Ward
- Department of Molecular Biology, University of Wyoming, Laramie, Wyoming, United States of America
| | - Jonathan A. Eisen
- UC Davis Genome Center, University of California Davis, Davis, California, United States of America
| | - Jonathan H. Badger
- J. Craig Venter Institute, San Diego, California, United States of America
| | - Daniel L. Distel
- Ocean Genome Legacy, Inc., Ipswich, Massachusetts, United States of America
- * E-mail:
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41
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Abstract
Type VI secretion systems (T6SSs) contribute to interactions of bacterial pathogens and symbionts with their hosts. Previously, we showed that Pseudomonas aeruginosa T6S is posttranslationally activated upon phosphorylation of Fha1, an FHA domain protein, by PpkA, a membrane-spanning threonine kinase. Herein, additional structural, enzymatic and genetic requirements for PpkA-catalysed T6SS activation are identified. We found that PpkA plays an essential structural role in the T6SS, and that this role is intimately linked to its ability to promote secretion and phosphorylate Fha1. Protein localization and protein-protein interaction studies show that a complex containing Fha1 and the T6S ATPase, ClpV1 is recruited to the T6S apparatus in a phosphorylation-dependent manner. The mechanism of PpkA activation was also investigated. We identified critical PpkA autophosphorylation sites and showed that small molecule-induced dimerization of the extracellular domains of PpkA is sufficient to activate the T6SS. Finally, we discovered TagR, a component of the T6S posttranslational regulatory pathway that functions upstream of PpkA to promote kinase activity. We present a model whereby an unknown cue causes dimerization of the extracellular domains of PpkA, leading to its autophosphorylation, recruitment of the Fha1-ClpV1 complex, phosphorylation of Fha1, and T6SS activation. Our findings should facilitate approaches for identifying physiological activators of T6S.
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Affiliation(s)
- FoSheng Hsu
- Department of Microbiology, University of Washington, Seattle, WA 98195, USA
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42
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Mougous JD, Gifford CA, Ramsdell TL, Mekalanos JJ. Threonine phosphorylation post-translationally regulates protein secretion in Pseudomonas aeruginosa. Nat Cell Biol 2007; 9:797-803. [PMID: 17558395 DOI: 10.1038/ncb1605] [Citation(s) in RCA: 236] [Impact Index Per Article: 13.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2006] [Accepted: 05/14/2007] [Indexed: 11/09/2022]
Abstract
Secreted proteins are crucial to the arsenal of bacterial pathogens. Although optimal activity of these proteins is likely to require precise regulation of release, the signalling events that trigger secretion are poorly understood. Here, we identify a threonine phosphorylation event that post-translationally regulates the Hcp secretion island-I-encoded type VI secretion system of Pseudomonas aeruginosa (H-T6SS). We show that a serine-threonine kinase, PpkA, is required for assembly of the H-T6SS and for secretion of Hcp1. PpkA activity is antagonized by PppA, a Ser-Thr phosphatase. These proteins exhibit reciprocal effects on the H-T6SS by acting on an FHA domain-containing protein, termed Fha1. Colocalization experiments with the T6S AAA+ family protein, ClpV1, indicate that Fha1 is a core scaffolding protein of the H-T6SS. Mutations affecting this H-T6S regulatory pathway provide a molecular explanation for the variation in Hcp1 secretion among clinical P. aeruginosa isolates. This mechanism of triggering secretion may be general, as many T6SSs contain orthologues of these proteins. Post-translational regulation of protein secretion by Thr phosphorylation is unprecedented in bacteria, and is likely to reflect the requirement for T6S to respond rapidly and reversibly to its environment.
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Affiliation(s)
- Joseph D Mougous
- Department of Microbiology and Molecular Genetics, Harvard Medical School, 200 Longwood Avenue, Boston, MA 02115, USA
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Senaratne RH, Mougous JD, Reader JR, Williams SJ, Zhang T, Bertozzi CR, Riley LW. Vaccine efficacy of an attenuated but persistent Mycobacterium tuberculosis cysH mutant. J Med Microbiol 2007; 56:454-458. [PMID: 17374883 DOI: 10.1099/jmm.0.46983-0] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
The emergence of drug-resistant Mycobacterium tuberculosis strains and the widespread occurrence of AIDS demand newer and more efficient control of tuberculosis. The protective efficacy of the current Mycobacterium bovis bacille Calmette-Guérin (BCG) vaccine is highly variable. Therefore, development of an effective new vaccine has gained momentum in recent years. Recently, several M. tuberculosis mutants were tested as potential vaccine candidates in the mouse model of tuberculosis. However, only some of these mutants were able to generate protection equivalent to that of BCG in mice. This study reports the vaccine potential of an attenuated 5'-adenosine phosphosulfate reductase mutant (DeltacysH) of M. tuberculosis. Immunization of mice with either BCG or DeltacysH followed by infection with the virulent M. tuberculosis Erdman strain demonstrated that DeltacysH can generate protection equivalent to that of the BCG vaccine.
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Affiliation(s)
- Ryan H Senaratne
- School of Public Health, University of California, Berkeley, CA 94720, USA
| | - Joseph D Mougous
- Department of Chemistry, University of California, Berkeley, CA 94720, USA
| | - J Rachel Reader
- Comparative Pathology Laboratory, School of Veterinary Medicine, University of California, Davis, CA 95616, USA
| | - Spencer J Williams
- Department of Chemistry, University of California, Berkeley, CA 94720, USA
| | - Tianjiao Zhang
- School of Public Health, University of California, Berkeley, CA 94720, USA
| | - Carolyn R Bertozzi
- Howard Hughes Medical Institute, University of California, Berkeley, CA 94720, USA
- Department of Molecular and Cell Biology, University of California, Berkeley, CA 94720, USA
- Department of Chemistry, University of California, Berkeley, CA 94720, USA
| | - Lee W Riley
- School of Public Health, University of California, Berkeley, CA 94720, USA
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Jain M, Petzold CJ, Schelle MW, Leavell MD, Mougous JD, Bertozzi CR, Leary JA, Cox JS. Lipidomics reveals control of Mycobacterium tuberculosis virulence lipids via metabolic coupling. Proc Natl Acad Sci U S A 2007; 104:5133-8. [PMID: 17360366 PMCID: PMC1829275 DOI: 10.1073/pnas.0610634104] [Citation(s) in RCA: 168] [Impact Index Per Article: 9.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Mycobacterium tuberculosis synthesizes specific polyketide lipids that interact with the host and are required for virulence. Using a mass spectrometric approach to simultaneously monitor hundreds of lipids, we discovered that the size and abundance of two lipid virulence factors, phthiocerol dimycocerosate (PDIM) and sulfolipid-1 (SL-1), are controlled by the availability of a common precursor, methyl malonyl CoA (MMCoA). Consistent with this view, increased levels of MMCoA led to increased abundance and mass of both PDIM and SL-1. Furthermore, perturbation of MMCoA metabolism attenuated pathogen replication in mice. Importantly, we detected increased PDIM synthesis in bacteria growing within host tissues and in bacteria grown in culture on odd-chain fatty acids. Because M. tuberculosis catabolizes host lipids to grow during infection, we propose that growth of M. tuberculosis on fatty acids in vivo leads to increased flux of MMCoA through lipid biosynthetic pathways, resulting in increased virulence lipid synthesis. Our results suggest that the shift to host lipid catabolism during infection allows for increased virulence lipid anabolism by the bacterium.
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Affiliation(s)
- Madhulika Jain
- *Department of Microbiology and Immunology, Program in Microbial Pathogenesis and Host Defense, University of California, San Francisco, CA 94143
| | - Christopher J. Petzold
- Genome Center, Departments of Chemistry and Molecular and Cellular Biology, University of California, Davis, CA 95616; and
| | | | - Michael D. Leavell
- Genome Center, Departments of Chemistry and Molecular and Cellular Biology, University of California, Davis, CA 95616; and
| | - Joseph D. Mougous
- Molecular and Cell Biology, and
- Howard Hughes Medical Institute, University of California, Berkeley, CA 94720
| | - Carolyn R. Bertozzi
- Departments of Chemistry and
- Molecular and Cell Biology, and
- Howard Hughes Medical Institute, University of California, Berkeley, CA 94720
| | - Julie A. Leary
- Genome Center, Departments of Chemistry and Molecular and Cellular Biology, University of California, Davis, CA 95616; and
| | - Jeffery S. Cox
- *Department of Microbiology and Immunology, Program in Microbial Pathogenesis and Host Defense, University of California, San Francisco, CA 94143
- To whom correspondence should be addressed. E-mail:
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Pi N, Hoang MB, Gao H, Mougous JD, Bertozzi CR, Leary JA. Kinetic measurements and mechanism determination of Stf0 sulfotransferase using mass spectrometry. Anal Biochem 2006; 341:94-104. [PMID: 15866533 DOI: 10.1016/j.ab.2005.02.004] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/12/2005] [Indexed: 11/26/2022]
Abstract
Mycobacterial carbohydrate sulfotransferase Stf0 catalyzes the sulfuryl group transfer from 3'-phosphoadenosine-5'-phosphosulfate (PAPS) to trehalose. The sulfation of trehalose is required for the biosynthesis of sulfolipid-1, the most abundant sulfated metabolite found in Mycobacterium tuberculosis. In this paper, an efficient enzyme kinetics assay for Stf0 using electrospray ionization (ESI) mass spectrometry is presented. The kinetic constants of Stf0 were measured, and the catalytic mechanism of the sulfuryl group transfer reaction was investigated in initial rate kinetics and product inhibition experiments. In addition, Fourier transform ion cyclotron resonance (FT-ICR) mass spectrometry was employed to detect the noncovalent complexes, the Stf0-PAPS and Stf0-trehalose binary complexes, and a Stf0-3'-phosphoadenosine 5'-phosphate-trehalose ternary complex. The results from our study strongly suggest a rapid equilibrium random sequential Bi-Bi mechanism for Stf0 with formation of a ternary complex intermediate. In this mechanism, PAPS and trehalose bind and their products are released in random fashion. To our knowledge, this is the first detailed mechanistic data reported for Stf0, which further demonstrates the power of mass spectrometry in elucidating the reaction pathway and catalytic mechanism of promising enzymatic systems.
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Affiliation(s)
- Na Pi
- Department of Chemistry and Division of Molecular and Cellular Biology, Genome Center, University of California, Davis, CA 95606, USA
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Mougous JD, Cuff ME, Raunser S, Shen A, Zhou M, Gifford CA, Goodman AL, Joachimiak G, Ordoñez CL, Lory S, Walz T, Joachimiak A, Mekalanos JJ. A virulence locus of Pseudomonas aeruginosa encodes a protein secretion apparatus. Science 2006; 312:1526-30. [PMID: 16763151 PMCID: PMC2800167 DOI: 10.1126/science.1128393] [Citation(s) in RCA: 797] [Impact Index Per Article: 44.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023]
Abstract
Bacterial pathogens frequently use protein secretion to mediate interactions with their hosts. Here we found that a virulence locus (HSI-I) of Pseudomonas aeruginosa encodes a protein secretion apparatus. The apparatus assembled in discrete subcellular locations and exported Hcp1, a hexameric protein that forms rings with a 40 angstrom internal diameter. Regulatory patterns of HSI-I suggested that the apparatus functions during chronic infections. We detected Hcp1 in pulmonary secretions of cystic fibrosis (CF) patients and Hcp1-specific antibodies in their sera. Thus, HSI-I likely contributes to the pathogenesis of P. aeruginosa in CF patients. HSI-I-related loci are widely distributed among bacterial pathogens and may play a general role in mediating host interactions.
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Affiliation(s)
- Joseph D. Mougous
- Department of Microbiology and Molecular Genetics, Harvard Medical School, Boston, MA 02115, USA
| | - Marianne E. Cuff
- Midwest Center for Structural Genomics and Structural Biology Center, Biosciences Division, Argonne National Laboratory, Argonne, IL 60439, USA
| | - Stefan Raunser
- Department of Cell Biology, Harvard Medical School, Boston, MA 02115, USA
| | - Aimee Shen
- Department of Microbiology and Molecular Genetics, Harvard Medical School, Boston, MA 02115, USA
| | - Min Zhou
- Midwest Center for Structural Genomics and Structural Biology Center, Biosciences Division, Argonne National Laboratory, Argonne, IL 60439, USA
| | - Casey A. Gifford
- Department of Microbiology and Molecular Genetics, Harvard Medical School, Boston, MA 02115, USA
| | - Andrew L. Goodman
- Department of Microbiology and Molecular Genetics, Harvard Medical School, Boston, MA 02115, USA
| | - Grazyna Joachimiak
- Midwest Center for Structural Genomics and Structural Biology Center, Biosciences Division, Argonne National Laboratory, Argonne, IL 60439, USA
| | - Claudia L. Ordoñez
- Division of Respiratory Diseases and Cystic Fibrosis Center, Children's Hospital Boston, Harvard Medical School, Boston, MA 02115, USA
| | - Stephen Lory
- Department of Microbiology and Molecular Genetics, Harvard Medical School, Boston, MA 02115, USA
| | - Thomas Walz
- Department of Cell Biology, Harvard Medical School, Boston, MA 02115, USA
| | - Andrzej Joachimiak
- Midwest Center for Structural Genomics and Structural Biology Center, Biosciences Division, Argonne National Laboratory, Argonne, IL 60439, USA
- Department of Biochemistry and Molecular Biology, University of Chicago, Chicago, IL 60637, USA
| | - John J. Mekalanos
- Department of Microbiology and Molecular Genetics, Harvard Medical School, Boston, MA 02115, USA
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Senaratne RH, De Silva AD, Williams SJ, Mougous JD, Reader JR, Zhang T, Chan S, Sidders B, Lee DH, Chan J, Bertozzi CR, Riley LW. 5'-Adenosinephosphosulphate reductase (CysH) protects Mycobacterium tuberculosis against free radicals during chronic infection phase in mice. Mol Microbiol 2006; 59:1744-53. [PMID: 16553880 DOI: 10.1111/j.1365-2958.2006.05075.x] [Citation(s) in RCA: 89] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
A major obstacle to tuberculosis (TB) control is the problem of chronic TB infection (CTBI). Here we report that 5'-adenosinephosphosulphate reductase (CysH), an enzyme essential for the production of reduced-sulphur-containing metabolites, is critical for Mycobacterium tuberculosis (Mtb) survival in chronic infection phase in mice. Disruption of cysH rendered Mtb auxotrophic for cysteine and methionine, and attenuated virulence in BALB/c and C57BL/6 immunocompetent mice. The mutant and wild-type Mtb replicated similarly during the acute phase of infection, but the mutant showed reduced viability during the persistent phase of the infection. The cysH mutant caused disease and death after 4-7 weeks of infection in four different groups of mice - Rag1(-/-), NOS2(-/-), gp91phox(-/-) NOS2(-/-) and gp91phox(-/-) mice given aminoguanidine [to suppress the effects of nitric oxide synthase 2 (NOS2)]- indicating minimal metabolic effect on the cysH mutant survival in these mice. The cysH mutant was also susceptible to peroxynitrite and hydrogen peroxide in vitro. These results show that CysH is important for Mtb protection during the chronic infection phase, and that resistance to nitrosative and oxidative stress may be the mechanism of this protection. Thus, this metabolic gene of an intracellular pathogen could have a secondary role in protection against the host immune response. Finally the lack of an endogenous human orthologue of cysH and its possible role in defence against adaptive immunity renders CysH an attractive enzyme for further studies as a target for therapeutics active against CTBI.
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Affiliation(s)
- Ryan H Senaratne
- School of Public Health, University of California, Berkeley, 94720, USA
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Mougous JD, Senaratne RH, Petzold CJ, Jain M, Lee DH, Schelle MW, Leavell MD, Cox JS, Leary JA, Riley LW, Bertozzi CR. A sulfated metabolite produced by stf3 negatively regulates the virulence of Mycobacterium tuberculosis. Proc Natl Acad Sci U S A 2006; 103:4258-63. [PMID: 16537518 PMCID: PMC1449680 DOI: 10.1073/pnas.0510861103] [Citation(s) in RCA: 45] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Sulfated molecules have been shown to modulate isotypic interactions between cells of metazoans and heterotypic interactions between bacterial pathogens or symbionts and their eukaryotic host cells. Mycobacterium tuberculosis, the causative agent of tuberculosis, produces sulfated molecules that have eluded functional characterization for decades. We demonstrate here that a previously uncharacterized sulfated molecule, termed S881, is localized to the outer envelope of M. tuberculosis and negatively regulates the virulence of the organism in two mouse infection models. Furthermore, we show that the biosynthesis of S881 relies on the universal sulfate donor 3'-phosphoadenosine-5'-phosphosulfate and a previously uncharacterized sulfotransferase, stf3. These findings extend the known functions of sulfated molecules as general modulators of cell-cell interactions to include those between a bacterium and a human host.
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Affiliation(s)
- Joseph D. Mougous
- Departments of *Molecular and Cell Biology and
- Howard Hughes Medical Institute, University of California, Berkeley, CA 94720; and
| | | | | | - Madhulika Jain
- Department of Microbiology and Immunology, G. W. Hooper Foundation, University of California, San Francisco, CA 94107
| | - Dong H. Lee
- Chemistry
- Howard Hughes Medical Institute, University of California, Berkeley, CA 94720; and
| | | | | | - Jeffery S. Cox
- Department of Microbiology and Immunology, G. W. Hooper Foundation, University of California, San Francisco, CA 94107
| | | | | | - Carolyn R. Bertozzi
- Departments of *Molecular and Cell Biology and
- Chemistry
- Howard Hughes Medical Institute, University of California, Berkeley, CA 94720; and
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Mougous JD, Lee DH, Hubbard SC, Schelle MW, Vocadlo DJ, Berger JM, Bertozzi CR. Molecular basis for G protein control of the prokaryotic ATP sulfurylase. Mol Cell 2006; 21:109-22. [PMID: 16387658 DOI: 10.1016/j.molcel.2005.10.034] [Citation(s) in RCA: 31] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/20/2005] [Revised: 09/19/2005] [Accepted: 10/27/2005] [Indexed: 01/10/2023]
Abstract
Sulfate assimilation is a critical component of both primary and secondary metabolism. An essential step in this pathway is the activation of sulfate through adenylation by the enzyme ATP sulfurylase (ATPS), forming adenosine 5'-phosphosulfate (APS). Proteobacterial ATPS overcomes this energetically unfavorable reaction by associating with a regulatory G protein, coupling the energy of GTP hydrolysis to APS formation. To discover the molecular basis of this unusual role for a G protein, we biochemically characterized and solved the X-ray crystal structure of a complex between Pseudomonas syringae ATPS (CysD) and its associated regulatory G protein (CysN). The structure of CysN*D shows the two proteins in tight association; however, the nucleotides bound to each subunit are spatially segregated. We provide evidence that conserved switch motifs in the G domain of CysN allosterically mediate interactions between the nucleotide binding sites. This structure suggests a molecular mechanism by which conserved G domain architecture is used to energetically link GTP turnover to the production of an essential metabolite.
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Affiliation(s)
- Joseph D Mougous
- Howard Hughes Medical Institute, University of California, Berkeley, Berkeley, California 94720, USA
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Abstract
An efficient enzyme kinetics assay using electrospray ionization mass spectrometry (ESI-MS) was initially applied to the catalytic mechanism investigation of a carbohydrate sulfotransferase, NodST. Herein, the recombinant NodST was overexpressed with a His(6)-tag and purified via Ni-NTA metal-affinity chromatography. In this bisubstrate enzymatic system, an internal standard similar in structure and ionization efficiency to the product was chosen in the ESI-MS assay, and a single point normalization factor was determined and used to quantify the product concentration. The catalytic mechanism of NodST was rapidly determined by fitting the MS kinetic data into a nonlinear regression analysis program. The initial rate kinetics analysis and product inhibition study described support a hybrid double-displacement, two-site ping-pong mechanism of NodST with formation of a sulfated NodST intermediate. This covalent intermediate was further isolated and detected via trypsin digestion and Fourier transform ion cyclotron resonance mass spectrometry. To our knowledge, these are the first mechanistic data reported for the bacterial sulfotransferase, NodST, which demonstrated the power of mass spectrometry in elucidating the reaction pathway and catalytic mechanism of promising enzymatic systems.
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Affiliation(s)
- Na Pi
- Department of Chemistry, University of California, Berkeley, CA 94720, USA
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