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Zhang D, Boch J. Development of TALE-adenine base editors in plants. Plant Biotechnol J 2024; 22:1067-1077. [PMID: 37997697 PMCID: PMC11022790 DOI: 10.1111/pbi.14246] [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] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/21/2022] [Revised: 10/10/2023] [Accepted: 11/13/2023] [Indexed: 11/25/2023]
Abstract
Base editors enable precise nucleotide changes at targeted genomic loci without requiring double-stranded DNA breaks or repair templates. TALE-adenine base editors (TALE-ABEs) are genome editing tools, composed of a DNA-binding domain from transcription activator-like effectors (TALEs), an engineered adenosine deaminase (TadA8e), and a cytosine deaminase domain (DddA), that allow A•T-to-G•C editing in human mitochondrial DNA. However, the editing ability of TALE-ABEs in plants apart from chloroplast DNA has not been described, so far, and the functional role how DddA enhances TadA8e is still unclear. We tested a series of TALE-ABEs with different deaminase fusion architectures in Nicotiana benthamiana and rice. The results indicate that the double-stranded DNA-specific cytosine deaminase DddA can boost the activities of single-stranded DNA-specific deaminases (TadA8e or APOBEC3A) on double-stranded DNA. We analysed A•T-to-G•C editing efficiencies in a β-glucuronidase reporter system and showed precise adenine editing in genomic regions with high product purity in rice protoplasts. Furthermore, we have successfully regenerated rice plants with A•T-to-G•C mutations in the chloroplast genome using TALE-ABE. Consequently, TALE-adenine base editors provide alternatives for crop improvement and gene therapy by editing nuclear or organellar genomes.
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Affiliation(s)
- Dingbo Zhang
- Institute of Plant GeneticsLeibniz Universität HannoverHannoverGermany
| | - Jens Boch
- Institute of Plant GeneticsLeibniz Universität HannoverHannoverGermany
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2
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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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3
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Geller AM, Shalom M, Zlotkin D, Blum N, Levy A. Identification of type VI secretion system effector-immunity pairs using structural bioinformatics. Mol Syst Biol 2024:10.1038/s44320-024-00035-8. [PMID: 38658795 DOI: 10.1038/s44320-024-00035-8] [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: 01/02/2024] [Revised: 03/24/2024] [Accepted: 04/09/2024] [Indexed: 04/26/2024] Open
Abstract
The type VI secretion system (T6SS) is an important mediator of microbe-microbe and microbe-host interactions. Gram-negative bacteria use the T6SS to inject T6SS effectors (T6Es), which are usually proteins with toxic activity, into neighboring cells. Antibacterial effectors have cognate immunity proteins that neutralize self-intoxication. Here, we applied novel structural bioinformatic tools to perform systematic discovery and functional annotation of T6Es and their cognate immunity proteins from a dataset of 17,920 T6SS-encoding bacterial genomes. Using structural clustering, we identified 517 putative T6E families, outperforming sequence-based clustering. We developed a logistic regression model to reliably quantify protein-protein interaction of new T6E-immunity pairs, yielding candidate immunity proteins for 231 out of the 517 T6E families. We used sensitive structure-based annotation which yielded functional annotations for 51% of the T6E families, again outperforming sequence-based annotation. Next, we validated four novel T6E-immunity pairs using basic experiments in E. coli. In particular, we showed that the Pfam domain DUF3289 is a homolog of Colicin M and that DUF943 acts as its cognate immunity protein. Furthermore, we discovered a novel T6E that is a structural homolog of SleB, a lytic transglycosylase, and identified a specific glutamate that acts as its putative catalytic residue. Overall, this study applies novel structural bioinformatic tools to T6E-immunity pair discovery, and provides an extensive database of annotated T6E-immunity pairs.
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Affiliation(s)
- Alexander M Geller
- Department of Plant Pathology and Microbiology, The Institute of Environmental Science, The Robert H. Smith Faculty of Agriculture, Food and Environment, The Hebrew University of Jerusalem, Rehovot, Israel
| | - Maor Shalom
- Department of Plant Pathology and Microbiology, The Institute of Environmental Science, The Robert H. Smith Faculty of Agriculture, Food and Environment, The Hebrew University of Jerusalem, Rehovot, Israel
| | - David Zlotkin
- Department of Plant Pathology and Microbiology, The Institute of Environmental Science, The Robert H. Smith Faculty of Agriculture, Food and Environment, The Hebrew University of Jerusalem, Rehovot, Israel
| | - Noam Blum
- Department of Plant Pathology and Microbiology, The Institute of Environmental Science, The Robert H. Smith Faculty of Agriculture, Food and Environment, The Hebrew University of Jerusalem, Rehovot, Israel
| | - Asaf Levy
- Department of Plant Pathology and Microbiology, The Institute of Environmental Science, The Robert H. Smith Faculty of Agriculture, Food and Environment, The Hebrew University of Jerusalem, Rehovot, Israel.
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4
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Harris RS, Carpenter MA. Deaminase deluge yields new opportunities for biotechnology and genome engineering. Mol Cell 2024; 84:816-818. [PMID: 38458171 DOI: 10.1016/j.molcel.2024.02.016] [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] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/15/2024] [Accepted: 02/16/2024] [Indexed: 03/10/2024]
Abstract
In this issue of Molecular Cell, Vaisvila et al.1 report a tour de force functional characterization of a large and highly diverse set of polynucleotide cytosine deaminase (PCD) enzymes, which is already propelling new biotechnology applications.
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Affiliation(s)
- Reuben S Harris
- Department of Biochemistry and Structural Biology and Howard Hughes Medical Institute, University of Texas Health San Antonio, San Antonio, TX 78229, USA.
| | - Michael A Carpenter
- Department of Biochemistry and Structural Biology and Howard Hughes Medical Institute, University of Texas Health San Antonio, San Antonio, TX 78229, USA
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5
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Vaisvila R, Johnson SR, Yan B, Dai N, Bourkia BM, Chen M, Corrêa IR, Yigit E, Sun Z. Discovery of cytosine deaminases enables base-resolution methylome mapping using a single enzyme. Mol Cell 2024; 84:854-866.e7. [PMID: 38402612 DOI: 10.1016/j.molcel.2024.01.027] [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] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/06/2023] [Revised: 11/02/2023] [Accepted: 01/30/2024] [Indexed: 02/27/2024]
Abstract
Deaminases have important uses in modification detection and genome editing. However, the range of applications is limited by the small number of characterized enzymes. To expand the toolkit of deaminases, we developed an in vitro approach that bypasses a major hurdle with their toxicity in cells. We assayed 175 putative cytosine deaminases on a variety of substrates and found a broad range of activity on double- and single-stranded DNA in various sequence contexts, including CpG-specific deaminases and enzymes without sequence preference. We also characterized enzyme selectivity across six DNA modifications and reported enzymes that do not deaminate modified cytosines. The detailed analysis of diverse deaminases opens new avenues for biotechnological and medical applications. As a demonstration, we developed SEM-seq, a non-destructive single-enzyme methylation sequencing method using a modification-sensitive double-stranded DNA deaminase. The streamlined protocol enables accurate, base-resolution methylome mapping of scarce biological material, including cell-free DNA and 10 pg input DNA.
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Affiliation(s)
| | - Sean R Johnson
- New England Biolabs Inc., 240 County Road, Ipswich, MA 01938, USA
| | - Bo Yan
- New England Biolabs Inc., 240 County Road, Ipswich, MA 01938, USA
| | - Nan Dai
- New England Biolabs Inc., 240 County Road, Ipswich, MA 01938, USA
| | - Billal M Bourkia
- New England Biolabs Inc., 240 County Road, Ipswich, MA 01938, USA
| | - Minyong Chen
- New England Biolabs Inc., 240 County Road, Ipswich, MA 01938, USA
| | - Ivan R Corrêa
- New England Biolabs Inc., 240 County Road, Ipswich, MA 01938, USA
| | - Erbay Yigit
- New England Biolabs Inc., 240 County Road, Ipswich, MA 01938, USA
| | - Zhiyi Sun
- New England Biolabs Inc., 240 County Road, Ipswich, MA 01938, USA.
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6
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Sun H, Wang Z, Shen L, Feng Y, Han L, Qian X, Meng R, Ji K, Liang D, Zhou F, Lou X, Zhang J, Shen B. Developing mitochondrial base editors with diverse context compatibility and high fidelity via saturated spacer library. Nat Commun 2023; 14:6625. [PMID: 37857619 PMCID: PMC10587121 DOI: 10.1038/s41467-023-42359-3] [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: 06/28/2023] [Accepted: 10/09/2023] [Indexed: 10/21/2023] Open
Abstract
DddA-derived cytosine base editors (DdCBEs) greatly facilitated the basic and therapeutic research of mitochondrial DNA mutation diseases. Here we devise a saturated spacer library and successfully identify seven DddA homologs by performing high-throughput sequencing based screen. DddAs of Streptomyces sp. BK438 and Lachnospiraceae bacterium sunii NSJ-8 display high deaminase activity with a strong GC context preference, and DddA of Ruminococcus sp. AF17-6 is highly compatible to AC context. We also find that different split sites result in wide divergence on off-target activity and context preference of DdCBEs derived from these DddA homologs. Additionally, we demonstrate the orthogonality between DddA and DddIA, and successfully minimize the nuclear off-target editing by co-expressing corresponding nuclear-localized DddIA. The current study presents a comprehensive and unbiased strategy for screening and characterizing dsDNA cytidine deaminases, and expands the toolbox for mtDNA editing, providing additional insights for optimizing dsDNA base editors.
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Affiliation(s)
- Haifeng Sun
- State Key Laboratory of Reproductive Medicine and Offspring Health, Women's Hospital of Nanjing Medical University, Nanjing Maternity and Child Health Care Hospital, Center for Global Health, Gusu School, Nanjing Medical University, Nanjing, 211166, China
| | - Zhaojun Wang
- State Key Laboratory of Reproductive Medicine and Offspring Health, Women's Hospital of Nanjing Medical University, Nanjing Maternity and Child Health Care Hospital, Center for Global Health, Gusu School, Nanjing Medical University, Nanjing, 211166, China
| | - Limini Shen
- State Key Laboratory of Reproductive Medicine and Offspring Health, Women's Hospital of Nanjing Medical University, Nanjing Maternity and Child Health Care Hospital, Center for Global Health, Gusu School, Nanjing Medical University, Nanjing, 211166, China
| | - Yeling Feng
- State Key Laboratory of Reproductive Medicine and Offspring Health, Women's Hospital of Nanjing Medical University, Nanjing Maternity and Child Health Care Hospital, Center for Global Health, Gusu School, Nanjing Medical University, Nanjing, 211166, China
| | - Lu Han
- State Key Laboratory of Reproductive Medicine and Offspring Health, Women's Hospital of Nanjing Medical University, Nanjing Maternity and Child Health Care Hospital, Center for Global Health, Gusu School, Nanjing Medical University, Nanjing, 211166, China
| | - Xuezhen Qian
- State Key Laboratory of Reproductive Medicine and Offspring Health, Women's Hospital of Nanjing Medical University, Nanjing Maternity and Child Health Care Hospital, Center for Global Health, Gusu School, Nanjing Medical University, Nanjing, 211166, China
| | - Runde Meng
- State Key Laboratory of Reproductive Medicine and Offspring Health, Women's Hospital of Nanjing Medical University, Nanjing Maternity and Child Health Care Hospital, Center for Global Health, Gusu School, Nanjing Medical University, Nanjing, 211166, China
| | - Kangming Ji
- State Key Laboratory of Reproductive Medicine and Offspring Health, Women's Hospital of Nanjing Medical University, Nanjing Maternity and Child Health Care Hospital, Center for Global Health, Gusu School, Nanjing Medical University, Nanjing, 211166, China
| | - Dong Liang
- Department of Prenatal Diagnosis, Women's Hospital of Nanjing Medical University, Nanjing Maternity and Child Health Care Hospital, Nanjing, 210004, China
| | - Fei Zhou
- Cambridge-Suda Genomic Resource Center, Suzhou Medical College of Soochow University, Suzhou, 215123, China
| | - Xin Lou
- Research Institute of Intelligent Computing, Zhejiang Lab, Hangzhou, 311100, China.
| | - Jun Zhang
- State Key Laboratory of Reproductive Medicine and Offspring Health, Women's Hospital of Nanjing Medical University, Nanjing Maternity and Child Health Care Hospital, Center for Global Health, Gusu School, Nanjing Medical University, Nanjing, 211166, China.
| | - Bin Shen
- State Key Laboratory of Reproductive Medicine and Offspring Health, Women's Hospital of Nanjing Medical University, Nanjing Maternity and Child Health Care Hospital, Center for Global Health, Gusu School, Nanjing Medical University, Nanjing, 211166, China.
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7
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Hagan M, Pankov G, Gallegos-Monterrosa R, Williams DJ, Earl C, Buchanan G, Hunter WN, Coulthurst SJ. Rhs NADase effectors and their immunity proteins are exchangeable mediators of inter-bacterial competition in Serratia. Nat Commun 2023; 14:6061. [PMID: 37770429 PMCID: PMC10539506 DOI: 10.1038/s41467-023-41751-3] [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: 02/13/2023] [Accepted: 09/05/2023] [Indexed: 09/30/2023] Open
Abstract
Many bacterial species use Type VI secretion systems (T6SSs) to deliver anti-bacterial effector proteins into neighbouring bacterial cells, representing an important mechanism of inter-bacterial competition. Specific immunity proteins protect bacteria from the toxic action of their own effectors, whilst orphan immunity proteins without a cognate effector may provide protection against incoming effectors from non-self competitors. T6SS-dependent Rhs effectors contain a variable C-terminal toxin domain (CT), with the cognate immunity protein encoded immediately downstream of the effector. Here, we demonstrate that Rhs1 effectors from two strains of Serratia marcescens, the model strain Db10 and clinical isolate SJC1036, possess distinct CTs which both display NAD(P)+ glycohydrolase activity but belong to different subgroups of NADase from each other and other T6SS-associated NADases. Comparative structural analysis identifies conserved functions required for NADase activity and reveals that unrelated NADase immunity proteins utilise a common mechanism of effector inhibition. By replicating a natural recombination event, we show successful functional exchange of CTs and demonstrate that Db10 encodes an orphan immunity protein which provides protection against T6SS-delivered SJC1036 NADase. Our findings highlight the flexible use of Rhs effectors and orphan immunity proteins during inter-strain competition and the repeated adoption of NADase toxins as weapons against bacterial cells.
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Affiliation(s)
- Martin Hagan
- School of Life Sciences, University of Dundee, Dow Street, Dundee, DD1 5EH, UK
| | - Genady Pankov
- School of Life Sciences, University of Dundee, Dow Street, Dundee, DD1 5EH, UK
| | | | - David J Williams
- School of Life Sciences, University of Dundee, Dow Street, Dundee, DD1 5EH, UK
| | - Christopher Earl
- School of Life Sciences, University of Dundee, Dow Street, Dundee, DD1 5EH, UK
| | - Grant Buchanan
- School of Life Sciences, University of Dundee, Dow Street, Dundee, DD1 5EH, UK
| | - William N Hunter
- School of Life Sciences, University of Dundee, Dow Street, Dundee, DD1 5EH, UK.
| | - Sarah J Coulthurst
- School of Life Sciences, University of Dundee, Dow Street, Dundee, DD1 5EH, UK.
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8
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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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9
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Yin L, Shi K, Aihara H. Structural basis of sequence-specific cytosine deamination by double-stranded DNA deaminase toxin DddA. Nat Struct Mol Biol 2023; 30:1153-1159. [PMID: 37460895 PMCID: PMC10442228 DOI: 10.1038/s41594-023-01034-3] [Citation(s) in RCA: 3] [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] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/04/2022] [Accepted: 06/12/2023] [Indexed: 07/21/2023]
Abstract
The interbacterial deaminase toxin DddA catalyzes cytosine-to-uracil conversion in double-stranded (ds) DNA and enables CRISPR-free mitochondrial base editing, but the molecular mechanisms underlying its unique substrate selectivity have remained elusive. Here, we report crystal structures of DddA bound to a dsDNA substrate containing the 5'-TC target motif. These structures show that DddA binds to the minor groove of a sharply bent dsDNA and engages the target cytosine extruded from the double helix. DddA Phe1375 intercalates in dsDNA and displaces the 5' (-1) thymine, which in turn replaces the target (0) cytosine and forms a noncanonical T-G base pair with the juxtaposed guanine. This tandem displacement mechanism allows DddA to locate a target cytosine without flipping it into the active site. Biochemical experiments demonstrate that DNA base mismatches enhance the DddA deaminase activity and relax its sequence selectivity. On the basis of the structural information, we further identified DddA mutants that exhibit attenuated activity or altered substrate preference. Our studies may help design new tools useful in genome editing or other applications.
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Affiliation(s)
- Lulu Yin
- Department of Biochemistry, Molecular Biology, and Biophysics, University of Minnesota, Minneapolis, MN, USA
- Institute for Molecular Virology, University of Minnesota, Minneapolis, MN, USA
- Masonic Cancer Center, University of Minnesota, Minneapolis, MN, USA
| | - Ke Shi
- Department of Biochemistry, Molecular Biology, and Biophysics, University of Minnesota, Minneapolis, MN, USA
- Institute for Molecular Virology, University of Minnesota, Minneapolis, MN, USA
- Masonic Cancer Center, University of Minnesota, Minneapolis, MN, USA
| | - Hideki Aihara
- Department of Biochemistry, Molecular Biology, and Biophysics, University of Minnesota, Minneapolis, MN, USA.
- Institute for Molecular Virology, University of Minnesota, Minneapolis, MN, USA.
- Masonic Cancer Center, University of Minnesota, Minneapolis, MN, USA.
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10
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Allsopp LP, Bernal P. Killing in the name of: T6SS structure and effector diversity. Microbiology (Reading) 2023; 169:001367. [PMID: 37490402 PMCID: PMC10433429 DOI: 10.1099/mic.0.001367] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/23/2023] [Accepted: 07/12/2023] [Indexed: 07/27/2023]
Abstract
The life of bacteria is challenging, to endure bacteria employ a range of mechanisms to optimize their environment, including deploying the type VI secretion system (T6SS). Acting as a bacterial crossbow, this system delivers effectors responsible for subverting host cells, killing competitors and facilitating general secretion to access common goods. Due to its importance, this lethal machine has been evolutionarily maintained, disseminated and specialized to fulfil these vital functions. In fact, T6SS structural clusters are present in over 25 % of Gram-negative bacteria, varying in number from one to six different genetic clusters per organism. Since its discovery in 2006, research on the T6SS has rapidly progressed, yielding remarkable breakthroughs. The identification and characterization of novel components of the T6SS, combined with biochemical and structural studies, have revealed fascinating mechanisms governing its assembly, loading, firing and disassembly processes. Recent findings have also demonstrated the efficacy of this system against fungal and Gram-positive cells, expanding its scope. Ongoing research continues to uncover an extensive and expanding repertoire of T6SS effectors, the genuine mediators of T6SS function. These studies are shedding light on new aspects of the biology of prokaryotic and eukaryotic organisms. This review provides a comprehensive overview of the T6SS, highlighting recent discoveries of its structure and the diversity of its effectors. Additionally, it injects a personal perspective on avenues for future research, aiming to deepen our understanding of this combative system.
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Affiliation(s)
- Luke P. Allsopp
- National Heart and Lung Institute, Imperial College London, London, UK
| | - Patricia Bernal
- Departamento de Microbiología, Facultad de Biología, Universidad de Sevilla, Sevilla 41012, Spain
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11
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Guo J, Yu W, Li M, Chen H, Liu J, Xue X, Lin J, Huang S, Shu W, Huang X, Liu Z, Wang S, Qiao Y. A DddA ortholog-based and transactivator-assisted nuclear and mitochondrial cytosine base editors with expanded target compatibility. Mol Cell 2023; 83:1710-1724.e7. [PMID: 37141888 DOI: 10.1016/j.molcel.2023.04.012] [Citation(s) in RCA: 10] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/09/2022] [Revised: 02/21/2023] [Accepted: 04/12/2023] [Indexed: 05/06/2023]
Abstract
Bacterial double-stranded DNA (dsDNA) cytosine deaminase DddAtox-derived cytosine base editor (DdCBE) and its evolved variant, DddA11, guided by transcription-activator-like effector (TALE) proteins, enable mitochondrial DNA (mtDNA) editing at TC or HC (H = A, C, or T) sequence contexts, while it remains relatively unattainable for GC targets. Here, we identified a dsDNA deaminase originated from a Roseburia intestinalis interbacterial toxin (riDddAtox) and generated CRISPR-mediated nuclear DdCBEs (crDdCBEs) and mitochondrial CBEs (mitoCBEs) using split riDddAtox, which catalyzed C-to-T editing at both HC and GC targets in nuclear and mitochondrial genes. Moreover, transactivator (VP64, P65, or Rta) fusion to the tail of DddAtox- or riDddAtox-mediated crDdCBEs and mitoCBEs substantially improved nuclear and mtDNA editing efficiencies by up to 3.5- and 1.7-fold, respectively. We also used riDddAtox-based and Rta-assisted mitoCBE to efficiently stimulate disease-associated mtDNA mutations in cultured cells and in mouse embryos with conversion frequencies of up to 58% at non-TC targets.
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Affiliation(s)
- Junfan Guo
- School of Life Science and Technology, ShanghaiTech University, Shanghai 201210, China
| | - Wenxia Yu
- School of Life Science and Technology, ShanghaiTech University, Shanghai 201210, China; Ninth People's Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai 200125, China; WLA Laboratories, Shanghai 201208, China
| | - Min Li
- Shanghai Institute of Precision Medicine, Shanghai 200125, China; Precise Genome Engineering Center, School of Life Sciences, Guangzhou University, Guangzhou 510006, China
| | - Hongyu Chen
- Institute of Neuroscience, CAS Center for Excellence in Brain Science and Intelligence Technology, CAS Key Laboratory of Primate Neurobiology, State Key Laboratory of Neuroscience, Chinese Academy of Sciences, Shanghai 200031, China
| | - Jie Liu
- Guangzhou Medical University, Guangzhou 511436, China
| | - Xiaowen Xue
- Precise Genome Engineering Center, School of Life Sciences, Guangzhou University, Guangzhou 510006, China
| | - Jianxiang Lin
- Ninth People's Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai 200125, China; Shanghai Institute of Precision Medicine, Shanghai 200125, China
| | | | - Wenjie Shu
- Bioinformatics Center of AMMS, Beijing 100850, China
| | - Xingxu Huang
- Zhejiang Lab, Hangzhou 311121, Zhejiang, China; Zhejiang Provincial Key Laboratory of Pancreatic Disease, The First Affiliated Hospital, and Institute of Translational Medicine, Zhejiang University School of Medicine, Hangzhou 310029, China
| | - Zhen Liu
- Institute of Neuroscience, CAS Center for Excellence in Brain Science and Intelligence Technology, CAS Key Laboratory of Primate Neurobiology, State Key Laboratory of Neuroscience, Chinese Academy of Sciences, Shanghai 200031, China.
| | - Shengqi Wang
- Bioinformatics Center of AMMS, Beijing 100850, China.
| | - Yunbo Qiao
- Ninth People's Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai 200125, China; Shanghai Institute of Precision Medicine, Shanghai 200125, China.
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12
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Singh RP, Kumari K. Bacterial type VI secretion system (T6SS): an evolved molecular weapon with diverse functionality. Biotechnol Lett 2023; 45:309-331. [PMID: 36683130 DOI: 10.1007/s10529-023-03354-2] [Citation(s) in RCA: 9] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/28/2022] [Revised: 12/14/2022] [Accepted: 01/05/2023] [Indexed: 01/24/2023]
Abstract
Bacterial secretion systems are nanomolecular complexes that release a diverse set of virulence factors/or proteins into its surrounding or translocate to their target host cells. Among these systems, type VI secretion system 'T6SS' is a recently discovered molecular secretion system which is widely distributed in Gram-negative (-ve) bacteria, and shares structural similarity with the puncturing device of bacteriophages. The presence of T6SS is an advantage to many bacteria as it delivers toxins to its neighbour pathogens for competitive survival, and also translocates protein effectors to the host cells, leading to disruption of lipid membranes, cell walls, and cytoskeletons etc. Recent studies have characterized both anti-prokaryotic and anti-eukaryotic effectors, where T6SS is involved in diverse cellular functions including favouring colonization, enhancing the survival, adhesive modifications, internalization, and evasion of the immune system. With the evolution of advanced genomics and proteomics tools, there has been an increase in the number of characterized T6SS effector arsenals and also more clear information about the adaptive significance of this complex system. The functions of T6SS are generally regulated at the transcription, post-transcription and post-translational levels through diverse mechanisms. In the present review, we aimed to provide information about the distribution of T6SS in diverse bacteria, any structural similarity/or dissimilarity, effectors proteins, functional significance, and regulatory mechanisms. We also tried to provide information about the diverse roles played by T6SS in its natural environments and hosts, and further any changes in the microbiome.
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Affiliation(s)
- Rajnish Prakash Singh
- Department of Bioengineering and Biotechnology, Birla Institute of Technology, Mesra, Ranchi, Jharkhand, 835215, India.
| | - Kiran Kumari
- Department of Bioengineering and Biotechnology, Birla Institute of Technology, Mesra, Ranchi, Jharkhand, 835215, India
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13
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Mi L, Shi M, Li YX, Xie G, Rao X, Wu D, Cheng A, Niu M, Xu F, Yu Y, Gao N, Wei W, Wang X, Wang Y. DddA homolog search and engineering expand sequence compatibility of mitochondrial base editing. Nat Commun 2023; 14:874. [PMID: 36797253 DOI: 10.1038/s41467-023-36600-2] [Citation(s) in RCA: 17] [Impact Index Per Article: 17.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/15/2022] [Accepted: 02/09/2023] [Indexed: 02/18/2023] Open
Abstract
Expanding mitochondrial base editing tools with broad sequence compatibility is of high need for both research and therapeutic purposes. In this study, we identify a DddA homolog from Simiaoa sunii (Ddd_Ss) which can efficiently deaminate cytosine in DC context in double-stranded DNA (dsDNA). We successfully develop Ddd_Ss-derived cytosine base editors (DdCBE_Ss) and introduce mutations at multiple mitochondrial DNA (mtDNA) loci including disease-associated mtDNA mutations in previously inaccessible GC context. Finally, by introducing a single amino acid substitution from Ddd_Ss, we successfully improve the activity and sequence compatibility of DdCBE derived from DddA of Burkholderia cenocepacia (DdCBE_Bc). Our study expands mtDNA editing tool boxes and provides resources for further screening and engineering dsDNA base editors for biological and therapeutic applications.
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14
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Robinson LA, Collins ACZ, Murphy RA, Davies JC, Allsopp LP. Diversity and prevalence of type VI secretion system effectors in clinical Pseudomonas aeruginosa isolates. Front Microbiol 2023; 13:1042505. [PMID: 36687572 PMCID: PMC9846239 DOI: 10.3389/fmicb.2022.1042505] [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] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/12/2022] [Accepted: 11/23/2022] [Indexed: 01/06/2023] Open
Abstract
Pseudomonas aeruginosa is an opportunistic pathogen and a major driver of morbidity and mortality in people with Cystic Fibrosis (CF). The Type VI secretion system (T6SS) is a molecular nanomachine that translocates effectors across the bacterial membrane into target cells or the extracellular environment enabling intermicrobial interaction. P. aeruginosa encodes three T6SS clusters, the H1-, H2- and H3-T6SS, and numerous orphan islands. Genetic diversity of T6SS-associated effectors in P. aeruginosa has been noted in reference strains but has yet to be explored in clinical isolates. Here, we perform a comprehensive bioinformatic analysis of the pangenome and T6SS effector genes in 52 high-quality clinical P. aeruginosa genomes isolated from CF patients and housed in the Personalised Approach to P. aeruginosa strain repository. We confirm that the clinical CF isolate pangenome is open and principally made up of accessory and unique genes that may provide strain-specific advantages. We observed genetic variability in some effector/immunity encoding genes and show that several well-characterised vgrG and PAAR islands are absent from numerous isolates. Our analysis shows clear evidence of disruption to T6SS genomic loci through transposon, prophage, and mobile genetic element insertions. We identified an orphan vgrG island in P. aeruginosa strain PAK and five clinical isolates using in silico analysis which we denote vgrG7, predicting a gene within this cluster to encode a Tle2 lipase family effector. Close comparison of T6SS loci in clinical isolates compared to reference P. aeruginosa strain PAO1 revealed the presence of genes encoding eight new T6SS effectors with the following putative functions: cytidine deaminase, lipase, metallopeptidase, NADase, and pyocin. Finally, the prevalence of characterised and putative T6SS effectors were assessed in 532 publicly available P. aeruginosa genomes, which suggests the existence of accessory effectors. Our in silico study of the P. aeruginosa T6SS exposes a level of genetic diversity at T6SS genomic loci not seen to date within P. aeruginosa, particularly in CF isolates. As understanding the effector repertoire is key to identifying the targets of T6SSs and its efficacy, this comprehensive analysis provides a path for future experimental characterisation of these mediators of intermicrobial competition and host manipulation.
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Affiliation(s)
- Luca A. Robinson
- National Heart and Lung Institute, Imperial College London, London, United Kingdom
| | - Alice C. Z. Collins
- National Heart and Lung Institute, Imperial College London, London, United Kingdom
| | - Ronan A. Murphy
- National Heart and Lung Institute, Imperial College London, London, United Kingdom
| | - Jane C. Davies
- National Heart and Lung Institute, Imperial College London, London, United Kingdom
- Department of Paediatric Respiratory Medicine, Royal Brompton Hospital, London, United Kingdom
| | - Luke P. Allsopp
- National Heart and Lung Institute, Imperial College London, London, United Kingdom
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15
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Hespanhol JT, Karman L, Sanchez-Limache DE, Bayer-Santos E. Intercepting biological messages: Antibacterial molecules targeting nucleic acids during interbacterial conflicts. Genet Mol Biol 2023; 46:e20220266. [PMID: 36880694 PMCID: PMC9990079 DOI: 10.1590/1678-4685-gmb-2022-0266] [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] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/21/2022] [Accepted: 12/25/2022] [Indexed: 03/08/2023] Open
Abstract
Bacteria live in polymicrobial communities and constantly compete for resources. These organisms have evolved an array of antibacterial weapons to inhibit the growth or kill competitors. The arsenal comprises antibiotics, bacteriocins, and contact-dependent effectors that are either secreted in the medium or directly translocated into target cells. During bacterial antagonistic encounters, several cellular components important for life become a weak spot prone to an attack. Nucleic acids and the machinery responsible for their synthesis are well conserved across the tree of life. These molecules are part of the information flow in the central dogma of molecular biology and mediate long- and short-term storage for genetic information. The aim of this review is to summarize the diversity of antibacterial molecules that target nucleic acids during antagonistic interbacterial encounters and discuss their potential to promote the emergence antibiotic resistance.
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Affiliation(s)
- Julia Takuno Hespanhol
- Universidade de São Paulo, Instituto de Ciências Biomédicas, Departamento de Microbiologia, São Paulo, SP, Brazil
| | - Lior Karman
- Universidade de São Paulo, Instituto de Ciências Biomédicas, Departamento de Microbiologia, São Paulo, SP, Brazil
| | | | - Ethel Bayer-Santos
- Universidade de São Paulo, Instituto de Ciências Biomédicas, Departamento de Microbiologia, São Paulo, SP, Brazil
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16
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Jana B, Keppel K, Fridman CM, Bosis E, Salomon D. Multiple T6SSs, Mobile Auxiliary Modules, and Effectors Revealed in a Systematic Analysis of the Vibrio parahaemolyticus Pan-Genome. mSystems 2022; 7:e0072322. [PMID: 36226968 DOI: 10.1128/msystems.00723-22] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022] Open
Abstract
Type VI secretion systems (T6SSs) play a major role in interbacterial competition and in bacterial interactions with eukaryotic cells. The distribution of T6SSs and the effectors they secrete vary between strains of the same bacterial species. Therefore, a pan-genome investigation is required to better understand the T6SS potential of a bacterial species of interest. Here, we performed a comprehensive, systematic analysis of T6SS gene clusters and auxiliary modules found in the pan-genome of Vibrio parahaemolyticus, an emerging pathogen widespread in marine environments. We identified 4 different T6SS gene clusters within genomes of this species; two systems appear to be ancient and widespread, whereas the other 2 systems are rare and appear to have been more recently acquired via horizontal gene transfer. In addition, we identified diverse T6SS auxiliary modules containing putative effectors with either known or predicted toxin domains. Many auxiliary modules are possibly horizontally shared between V. parahaemolyticus genomes, since they are flanked by DNA mobility genes. We further investigated a DUF4225-containing protein encoded on an Hcp auxiliary module, and we showed that it is an antibacterial T6SS effector that exerts its toxicity in the bacterial periplasm, leading to cell lysis. Computational analyses of DUF4225 revealed a widespread toxin domain associated with various toxin delivery systems. Taken together, our findings reveal a diverse repertoire of T6SSs and auxiliary modules in the V. parahaemolyticus pan-genome, as well as novel T6SS effectors and toxin domains that can play a major role in the interactions of this species with other cells. IMPORTANCE Gram-negative bacteria employ toxin delivery systems to mediate their interactions with neighboring cells. Vibrio parahaemolyticus, an emerging pathogen of humans and marine animals, was shown to deploy antibacterial toxins into competing bacteria via the type VI secretion system (T6SS). Here, we analyzed 1,727 V. parahaemolyticus genomes and revealed the pan-genome T6SS repertoire of this species, including the T6SS gene clusters, horizontally shared auxiliary modules, and toxins. We also identified a role for a previously uncharacterized domain, DUF4225, as a widespread antibacterial toxin associated with diverse toxin delivery systems.
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17
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Crisan CV, Goldberg JB. Antibacterial contact-dependent proteins secreted by Gram-negative cystic fibrosis respiratory pathogens. Trends Microbiol 2022; 30:986-996. [PMID: 35487848 PMCID: PMC9474641 DOI: 10.1016/j.tim.2022.03.009] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [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] [Received: 11/30/2021] [Revised: 02/25/2022] [Accepted: 03/29/2022] [Indexed: 01/11/2023]
Abstract
Cystic fibrosis (CF) is a genetic disease that affects almost 100 000 people worldwide. CF patients suffer from chronic bacterial airway infections that are often polymicrobial and are the leading cause of mortality. Interactions between pathogens modulate expression of genes responsible for virulence and antibiotic resistance. One of the ways bacteria can interact is through contact-dependent systems, which secrete antibacterial proteins (effectors) that confer advantages to cells that harbor them. Here, we highlight recent work that describes effectors used by Gram-negative CF pathogens to eliminate competitor bacteria. Understanding the mechanisms of secreted effectors may lead to novel insights into the ecology of bacteria that colonize respiratory tracts and could also pave the way for the design of new therapeutics.
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Affiliation(s)
- Cristian V Crisan
- Department of Pediatrics, Division of Pulmonary, Asthma, Cystic Fibrosis, and Sleep, Emory University School of Medicine, Atlanta, GA, USA; Emory+Children's Center for Cystic Fibrosis and Airway Disease Research, Emory University School of Medicine, Atlanta, GA, USA
| | - Joanna B Goldberg
- Department of Pediatrics, Division of Pulmonary, Asthma, Cystic Fibrosis, and Sleep, Emory University School of Medicine, Atlanta, GA, USA; Emory+Children's Center for Cystic Fibrosis and Airway Disease Research, Emory University School of Medicine, Atlanta, GA, USA.
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18
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Carobbi A, Di Nepi S, Fridman CM, Dar Y, Ben‐Yaakov R, Barash I, Salomon D, Sessa G. An antibacterial T6SS in Pantoea agglomerans pv. betae delivers a lysozyme-like effector to antagonize competitors. Environ Microbiol 2022; 24:4787-4802. [PMID: 35706135 PMCID: PMC9796082 DOI: 10.1111/1462-2920.16100] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [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: 12/02/2021] [Accepted: 06/10/2022] [Indexed: 12/30/2022]
Abstract
The type VI secretion system (T6SS) is deployed by numerous Gram-negative bacteria to deliver toxic effectors into neighbouring cells. The genome of Pantoea agglomerans pv. betae (Pab) phytopathogenic bacteria contains a gene cluster (T6SS1) predicted to encode a complete T6SS. Using secretion and competition assays, we found that T6SS1 in Pab is a functional antibacterial system that allows this pathogen to outcompete rival plant-associated bacteria found in its natural environment. Computational analysis of the T6SS1 gene cluster revealed that antibacterial effector and immunity proteins are encoded within three genomic islands that also harbour arrays of orphan immunity genes or toxin and immunity cassettes. Functional analyses indicated that VgrG, a specialized antibacterial effector, contains a C-terminal catalytically active glucosaminidase domain that is used to degrade prey peptidoglycan. Moreover, we confirmed that a bicistronic unit at the end of the T6SS1 cluster encodes a novel antibacterial T6SS effector and immunity pair. Together, these results demonstrate that Pab T6SS1 is an antibacterial system delivering a lysozyme-like effector to eliminate competitors, and indicate that this bacterium contains additional novel T6SS effectors.
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Affiliation(s)
- Andrea Carobbi
- School of Plant Sciences and Food Security, The George S. Wise Faculty of Life SciencesTel‐Aviv UniversityTel‐Aviv
| | - Simone Di Nepi
- School of Plant Sciences and Food Security, The George S. Wise Faculty of Life SciencesTel‐Aviv UniversityTel‐Aviv
| | - Chaya M. Fridman
- Department of Clinical Microbiology and Immunology, Sackler Faculty of MedicineTel Aviv UniversityTel Aviv
| | - Yasmin Dar
- Department of Clinical Microbiology and Immunology, Sackler Faculty of MedicineTel Aviv UniversityTel Aviv
| | - Rotem Ben‐Yaakov
- Department of Clinical Microbiology and Immunology, Sackler Faculty of MedicineTel Aviv UniversityTel Aviv
| | - Isaac Barash
- School of Plant Sciences and Food Security, The George S. Wise Faculty of Life SciencesTel‐Aviv UniversityTel‐Aviv
| | - Dor Salomon
- Department of Clinical Microbiology and Immunology, Sackler Faculty of MedicineTel Aviv UniversityTel Aviv
| | - Guido Sessa
- School of Plant Sciences and Food Security, The George S. Wise Faculty of Life SciencesTel‐Aviv UniversityTel‐Aviv
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19
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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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20
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Nambiar TS, Baudrier L, Billon P, Ciccia A. CRISPR-based genome editing through the lens of DNA repair. Mol Cell 2022; 82:348-388. [PMID: 35063100 PMCID: PMC8887926 DOI: 10.1016/j.molcel.2021.12.026] [Citation(s) in RCA: 63] [Impact Index Per Article: 31.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/15/2021] [Revised: 12/18/2021] [Accepted: 12/20/2021] [Indexed: 01/22/2023]
Abstract
Genome editing technologies operate by inducing site-specific DNA perturbations that are resolved by cellular DNA repair pathways. Products of genome editors include DNA breaks generated by CRISPR-associated nucleases, base modifications induced by base editors, DNA flaps created by prime editors, and integration intermediates formed by site-specific recombinases and transposases associated with CRISPR systems. Here, we discuss the cellular processes that repair CRISPR-generated DNA lesions and describe strategies to obtain desirable genomic changes through modulation of DNA repair pathways. Advances in our understanding of the DNA repair circuitry, in conjunction with the rapid development of innovative genome editing technologies, promise to greatly enhance our ability to improve food production, combat environmental pollution, develop cell-based therapies, and cure genetic and infectious diseases.
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Affiliation(s)
- Tarun S. Nambiar
- Department of Genetics and Development, Herbert Irving Comprehensive Cancer Center, Columbia University Irving Medical Center, New York, NY 10032
| | - Lou Baudrier
- Department of Biochemistry and Molecular Biology, Robson DNA Science Centre, Arnie Charbonneau Cancer Institute, Cumming School of Medicine, University of Calgary, 3330 Hospital Drive N. W., Calgary, Alberta T2N 4N1, Canada
| | - Pierre Billon
- Department of Biochemistry and Molecular Biology, Robson DNA Science Centre, Arnie Charbonneau Cancer Institute, Cumming School of Medicine, University of Calgary, 3330 Hospital Drive N. W., Calgary, Alberta T2N 4N1, Canada,Corresponding authors: ,
| | - Alberto Ciccia
- Department of Genetics and Development, Herbert Irving Comprehensive Cancer Center, Columbia University Irving Medical Center, New York, NY 10032,Lead Contact,Corresponding authors: ,
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21
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De Jong M, Alto NM. Toxins, mutations and adaptations. eLife 2021; 10:66676. [PMID: 33620030 PMCID: PMC7901869 DOI: 10.7554/elife.66676] [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] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/18/2021] [Accepted: 02/18/2021] [Indexed: 11/21/2022] Open
Abstract
The toxins that some bacteria secrete to kill off rival species can also generate mutations that help toxin-resistant populations adapt to new environments.
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Affiliation(s)
- Maarten De Jong
- Department of Microbiology, University of Texas Southwestern Medical Center, Dallas, United States
| | - Neal M Alto
- Department of Microbiology, University of Texas Southwestern Medical Center, Dallas, United States
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22
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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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