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DarTG system

traitmech:000243 · CLASS · PROPOSED

A phage defense system in which an organism possesses a DarTG toxin-antitoxin locus whose DarT toxin can be released during bacteriophage infection to ADP-ribosylate viral DNA, block phage genome replication, and prevent production of mature virions.

Trait evidence (6)

  • DOI:10.1038/s41564-022-01153-5
    Representatives from two different subfamilies, DarTG1 and DarTG2, strongly protected E. coli MG1655 against different phages.

    LeRoux et al. support DarTG as a two-subfamily phage-defense system with experimental activity in E. coli MG1655 challenge assays.

  • DOI:10.1038/s41564-022-01153-5
    infection with either RB69 or T5 phage, respectively, triggers release of the DarT toxin, a DNA ADP-ribosyltransferase, that then modifies viral DNA and prevents replication, thereby blocking the production of mature virions

    LeRoux et al. support the DarT release, viral-DNA ADP-ribosylation, phage-genome-replication blockade, and mature-virion-production blockade captured in the causal graph.

  • DOI:10.1038/s41564-022-01153-5
    Collectively, our results indicate that phage defence may be a common function for TA systems and reveal the mechanism by which DarTG systems inhibit phage infection.

    LeRoux et al. support DarTG as an experimentally resolved toxin-antitoxin phage-defense system.

  • DOI:10.1128/mbio.00111-24
    we identify clinical isolates of the global pathogen Vibrio cholerae harboring a novel genetic element encoding the bacterial immune system DarTG and reveal the immune system's impact on the co-circulating lytic phage ICP1.

    Patel and Seed independently support DarTG as a bacterial immune system in V. cholerae clinical isolates and connect the system to defense against ICP1 phage.

  • DOI:10.1128/mbio.00111-24
    We show that DarTG inhibits ICP1 genome replication, thus preventing ICP1 plaquing.

    Patel and Seed support phage-genome-replication blockade as an output of the V. cholerae DarTG system.

  • DOI:10.1128/mbio.00111-24
    we probe clinical V. cholerae isolates for novel anti-phage immune systems that can inhibit ICP1 and discover the toxin-antitoxin system DarTG as a potent inhibitor.

    Patel and Seed support the DarTG toxin-antitoxin system as a potent inhibitor of the co-circulating phage ICP1.

DarTG loci couple phage infection to viral-DNA ADP-ribosylation

Evidence-backed process sketch linking sensitive phage infection to DarT toxin release, viral DNA ADP-ribosylation, inhibition of phage genome replication, restricted phage propagation, and the DarTG system trait.

NONMECHANISTIC · The graph captures LeRoux and Patel DarTG phage-defense evidence without claiming a universal phage trigger, DarT release mechanism, viral target scope, or phage-encoded anti-DarT factor across all DarTG systems.

DarTG loci couple phage infection to viral-DNA ADP-ribosylation Interactive directed graph showing evidence-backed causal relationships for DarTG system.

Edge evidence

  • sensitive phage infection triggers DarT toxin release

    Infection by RB69 or T5 phage triggers release of the DarT toxin in the tested DarTG subfamily systems.

    • DOI:10.1038/s41564-022-01153-5 infection with either RB69 or T5 phage, respectively, triggers release of the DarT toxin LeRoux et al. identify phage infection as the upstream trigger for DarT toxin release.
  • DarT toxin release contributes to viral DNA ADP-ribosylation RO:0002326

    Released DarT ADP-ribosylates viral DNA after phage infection.

    • DOI:10.1038/s41564-022-01153-5 triggers release of the DarT toxin, a DNA ADP-ribosyltransferase, that then modifies viral DNA LeRoux et al. support DarT release leading to viral-DNA ADP-ribosylation.
  • viral DNA ADP-ribosylation contributes to inhibited phage genome replication RO:0002326

    DarT-dependent viral-DNA modification blocks replication of the infecting phage genome.

    • DOI:10.1038/s41564-022-01153-5 then modifies viral DNA and prevents replication, thereby blocking the production of mature virions LeRoux et al. directly connect viral-DNA modification to blocked phage replication.
    • DOI:10.1128/mbio.00111-24 We show that DarTG inhibits ICP1 genome replication, thus preventing ICP1 plaquing. Patel and Seed show that V. cholerae DarTG also blocks ICP1 genome replication.
  • inhibited phage genome replication contributes to restricted phage propagation RO:0002326

    Inhibition of genome replication restricts mature virion production and phage plaquing.

    • DOI:10.1038/s41564-022-01153-5 prevents replication, thereby blocking the production of mature virions LeRoux et al. support mature-virion blockade as a downstream effect of blocked phage replication.
    • DOI:10.1128/mbio.00111-24 DarTG inhibits ICP1 genome replication, thus preventing ICP1 plaquing Patel and Seed support plaquing prevention as a downstream effect of ICP1 genome-replication blockade.
  • restricted phage propagation confers DarTG system METPO:2007700

    The DarTG system trait is realized by inhibition of phage replication and propagation.

    • DOI:10.1038/s41564-022-01153-5 reveal the mechanism by which DarTG systems inhibit phage infection LeRoux et al. place the DNA ADP-ribosylation mechanism in the broader DarTG phage-infection-inhibition trait.
  • DarTG system is a phage defense system rdfs:subClassOf

    DarTG system possession is a phage-defense-system trait.

    • DOI:10.1128/mbio.00111-24 we probe clinical V. cholerae isolates for novel anti-phage immune systems that can inhibit ICP1 and discover the toxin-antitoxin system DarTG as a potent inhibitor. Patel and Seed support DarTG as an anti-phage immune system.

Provenance

Identifier source
TraitMech local identifier
Definition source
DOI:10.1038/s41564-022-01153-5

Parent traits (1)

Synonyms (1)

  • DarTG toxin-antitoxin system EXACT_SYNONYM · DOI:10.1038/s41564-022-01153-5

kg-microbe context

No kg-microbe node embedding matched this record in the 2026-04-25 deepwalk.

Canonical examples (1)

Organisms cited as exemplars of this trait. Taxon ids are NCBITaxon and link out to the NCBI record.

  • Vibrio cholerae NCBITaxon:666 DOI:10.1128/mbio.00111-24 Patel and Seed characterized a phage defense element encoding DarTG in 2008-2009 clinical V. cholerae isolates and showed DarTG was responsible for ICP1 inhibition.

Curation history

  1. · MINTED_TRAITMECH_ID · codex

    Minted DarTG system as a DOI-backed GENOMICS TraitRecord under phage defense system after an ignored-and-hidden duplicate review found no exact live TraitMech, METPO, or prior proposal record; the replacement placeholder is reserved in proposals/metpo_traitmech_v120.