TraitMech

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RADAR system

traitmech:000238 · CLASS · PROPOSED

A phage defense system in which an organism possesses a restriction by an adenosine deaminase acting on RNA locus encoding an RdrA AAA+ ATPase and an RdrB adenosine deaminase that assemble into a supramolecular defense complex to modify adenosine-containing substrates and inhibit bacteriophage replication.

Trait evidence (6)

  • DOI:10.1016/j.cell.2023.01.012
    RADAR is a two-protein bacterial defense system that was reported to defend against phage

    Duncan-Lowey et al. support RADAR as a named bacterial phage-defense system.

  • DOI:10.1016/j.cell.2023.01.012
    revealing RdrA as a heptameric, two-layered AAA+ ATPase and RdrB as a dodecameric, hollow complex with twelve surface-exposed deaminase active sites

    Duncan-Lowey et al. support the RdrA AAA+ ATPase and RdrB adenosine-deaminase complex components.

  • DOI:10.1016/j.cell.2023.01.012
    RdrB catalyzes ATP-to-ITP conversion in vitro and induces the massive accumulation of inosine mononucleotides during phage infection in vivo, limiting phage replication

    Duncan-Lowey et al. support ATP-to-ITP deamination and inosine-mononucleotide accumulation as RADAR antiphage outputs.

  • DOI:10.1016/j.cell.2023.01.012
    When heterologously expressed in E. coli MG1655, all RADAR systems conferred defense against the closely related T-even phages T2, T4, and T6

    Duncan-Lowey et al. support the E. coli P0304799.3 RADAR locus as experimentally investigated and antiphage-active when cloned into E. coli MG1655.

  • DOI:10.1016/j.cell.2023.01.026
    RADAR contains an adenosine triphosphatase (RdrA) and an adenosine deaminase (RdrB)

    Gao et al. independently support defining RADAR around the RdrA ATPase and RdrB deaminase components.

  • DOI:10.1016/j.cell.2023.01.026
    up to twelve RdrA rings can dock one RdrB cage with precise alignments between deaminase catalytic pockets and RNA-translocation channels

    Gao et al. independently resolve RADAR RdrA/RdrB supramolecular assemblies while supporting an RNA-translocation interpretation of the deaminase substrate.

RADAR RdrA/RdrB complexes couple deamination to phage defense

Evidence-backed process sketch covering RADAR locus assembly, infection-associated adenosine-substrate deamination, inosine nucleotide accumulation, and inhibition of phage replication without asserting the unresolved exact coupling step.

NONMECHANISTIC · The graph stays at the RADAR-family level and uses the mononucleotide-deamination mechanism from Duncan-Lowey et al. without asserting that the exact RdrA activation trigger, ATP-versus-RNA substrate, inosine toxicity route, or abortive-infection output is resolved across all RADAR loci.

RADAR RdrA/RdrB complexes couple deamination to phage defense Interactive directed graph showing evidence-backed causal relationships for RADAR system.

Edge evidence

  • RADAR locus contributes to RdrA/RdrB supramolecular complex assembly RO:0002326

    RADAR loci encode RdrA and RdrB proteins that assemble into a supramolecular defense complex.

    • DOI:10.1016/j.cell.2023.01.012 RdrA and RdrB join to form a giant assembly up to 10 MDa Duncan-Lowey et al. support RdrA/RdrB RADAR complex assembly.
  • RADAR adenosine-substrate deamination contributes to inosine nucleotide accumulation RO:0002326

    RADAR-associated ATP-to-ITP deamination drives inosine-mononucleotide accumulation during phage infection.

    • DOI:10.1016/j.cell.2023.01.012 RdrB catalyzes ATP-to-ITP conversion in vitro and induces the massive accumulation of inosine mononucleotides during phage infection in vivo Duncan-Lowey et al. connect RdrB ATP-to-ITP catalysis to phage-infection-associated inosine mononucleotide accumulation.
  • inosine nucleotide accumulation mitigates phage replication METPO:2007407

    RADAR-induced inosine nucleotide accumulation limits phage replication.

    • DOI:10.1016/j.cell.2023.01.012 RdrB catalyzes ATP-to-ITP conversion in vitro and induces the massive accumulation of inosine mononucleotides during phage infection in vivo, limiting phage replication Duncan-Lowey et al. support inosine mononucleotide accumulation as a phage-limiting RADAR output.
  • RADAR adenosine-substrate deamination confers RADAR system METPO:2007700

    RADAR-mediated adenosine-nucleotide deamination realizes the RADAR antiphage phenotype.

    • DOI:10.1016/j.cell.2023.01.012 rapid deamination of adenosine nucleotides is a key mediator of RADAR anti-phage defense Duncan-Lowey et al. connect rapid adenosine-nucleotide deamination, rather than downstream inosine accumulation alone, to RADAR antiphage defense.
  • RADAR system is a phage defense system rdfs:subClassOf

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

    • DOI:10.1016/j.cell.2023.01.012 RADAR is a two-protein bacterial defense system that was reported to defend against phage Duncan-Lowey et al. support RADAR as a bacterial phage-defense system.

Provenance

Identifier source
TraitMech local identifier
Definition source
DOI:10.1016/j.cell.2023.01.012

Parent traits (1)

Synonyms (1)

  • restriction by an adenosine deaminase acting on RNA EXACT_SYNONYM · DOI:10.1016/j.cell.2023.01.012

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.

  • Escherichia coli NCBITaxon:562 DOI:10.1016/j.cell.2023.01.012 Duncan-Lowey et al. selected the RADAR system from E. coli P0304799.3 for experimental investigation and reported that it conferred defense against T-even phages when heterologously expressed in E. coli MG1655.

Discussions and Knowledge Gaps (1)

Open questions attached to this trait. Seeded by just knowledge-gap-scan and curated; see the corpus-wide index.

Resolve RADAR phage triggers, RdrA activation, ATP-versus-RNA deamination, and inosine nucleotide toxicity before minting narrower RADAR mechanism children.

KNOWLEDGE GAP OPEN radar-trigger-and-substrate-gap · raised by codex · 2026-09-18

Not yet attached to a section of this record — a curator sets attaches_to (e.g. causal_graphs#some_edge) so the gap shows beside the mechanism it concerns.

Gao et al. support an RNA translocation and deamination model for RdrA/RdrB RADAR assemblies, whereas Duncan-Lowey et al. found that ATP and dATP mononucleotide deamination rather than robust RNA editing mediates RADAR immunity. The first TraitRecord therefore stays at the RADAR-system level until separate review resolves which activating phage cues, RdrA sensor states, deaminase substrates, and inosine toxicity routes generalize across RADAR loci.

Curation history

  1. · MINTED_TRAITMECH_ID · codex

    Minted RADAR system as a DOI-backed GENOMICS TraitRecord under the phage defense system parent 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_v115.

  2. · ADVERSARIAL_REVIEW_REPAIR · codex

    Resolved PR #978 review follow-ups #979, #980, and #981 plus PR #982 review follow-ups #983, #984, and #985 by removing the unsupported RADAR-locus-to-deamination edge, rewiring the RADAR confers edge to adenosine-nucleotide deamination, and normalizing the initial per-record curation timestamp while leaving the append-only session history record intact.