identifier: traitmech:000238 label: RADAR system definition: 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. definition_source: DOI:10.1016/j.cell.2023.01.012 trait_category: GENOMICS term_kind: CLASS mapping_status: PROPOSED parent_traits: - traitmech:000209 synonyms: - synonym_text: restriction by an adenosine deaminase acting on RNA synonym_type: EXACT_SYNONYM source: DOI:10.1016/j.cell.2023.01.012 evidence: - reference: DOI:10.1016/j.cell.2023.01.012 snippet: RADAR is a two-protein bacterial defense system that was reported to defend against phage notes: Duncan-Lowey et al. support RADAR as a named bacterial phage-defense system. - reference: DOI:10.1016/j.cell.2023.01.012 snippet: revealing RdrA as a heptameric, two-layered AAA+ ATPase and RdrB as a dodecameric, hollow complex with twelve surface-exposed deaminase active sites notes: Duncan-Lowey et al. support the RdrA AAA+ ATPase and RdrB adenosine-deaminase complex components. - reference: DOI:10.1016/j.cell.2023.01.012 snippet: RdrB catalyzes ATP-to-ITP conversion in vitro and induces the massive accumulation of inosine mononucleotides during phage infection in vivo, limiting phage replication notes: Duncan-Lowey et al. support ATP-to-ITP deamination and inosine-mononucleotide accumulation as RADAR antiphage outputs. - reference: DOI:10.1016/j.cell.2023.01.012 snippet: When heterologously expressed in E. coli MG1655, all RADAR systems conferred defense against the closely related T-even phages T2, T4, and T6 notes: Duncan-Lowey et al. support the E. coli P0304799.3 RADAR locus as experimentally investigated and antiphage-active when cloned into E. coli MG1655. - reference: DOI:10.1016/j.cell.2023.01.026 snippet: RADAR contains an adenosine triphosphatase (RdrA) and an adenosine deaminase (RdrB) notes: Gao et al. independently support defining RADAR around the RdrA ATPase and RdrB deaminase components. - reference: DOI:10.1016/j.cell.2023.01.026 snippet: up to twelve RdrA rings can dock one RdrB cage with precise alignments between deaminase catalytic pockets and RNA-translocation channels notes: Gao et al. independently resolve RADAR RdrA/RdrB supramolecular assemblies while supporting an RNA-translocation interpretation of the deaminase substrate. canonical_examples: - taxon_id: NCBITaxon:562 taxon_label: Escherichia coli note: 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. reference: DOI:10.1016/j.cell.2023.01.012 causal_graphs: - graph_id: radar_rdrab_deamination_antiphage_defense title: RADAR RdrA/RdrB complexes couple deamination to phage defense description: 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. scope_status: NONMECHANISTIC scope_notes: 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. nodes: - node_id: radar_locus label: RADAR locus node_type: GENETIC_ELEMENT description: A complete restriction by an adenosine deaminase acting on RNA locus encoding RdrA and RdrB components. - node_id: rdra_rdrb_complex_assembly label: RdrA/RdrB supramolecular complex assembly node_type: BIOLOGICAL_PROCESS description: Assembly of the RdrA AAA+ ATPase and RdrB adenosine deaminase into a supramolecular RADAR defense complex. - node_id: adenosine_substrate_deamination label: RADAR adenosine-substrate deamination node_type: BIOLOGICAL_PROCESS description: RdrB-associated deamination of adenosine-containing substrates during RADAR activation. - node_id: inosine_nucleotide_accumulation label: inosine nucleotide accumulation node_type: BIOLOGICAL_PROCESS description: Accumulation of inosine nucleotides such as ITP and dITP in infected cells. - node_id: phage_replication label: phage replication node_type: BIOLOGICAL_PROCESS description: Bacteriophage genome replication and production inside an infected bacterial host. - node_id: radar_system_trait label: RADAR system node_type: TRAIT grounding: traitmech:000238 description: Possession of a genome-encoded RADAR phage-defense system. - node_id: phage_defense_system label: phage defense system node_type: TRAIT grounding: traitmech:000209 description: Possession of one or more genome-encoded immune systems that inhibit bacteriophage infection. edges: - subject: radar_locus predicate: contributes to predicate_id: RO:0002326 object: rdra_rdrb_complex_assembly description: RADAR loci encode RdrA and RdrB proteins that assemble into a supramolecular defense complex. evidence: - reference: DOI:10.1016/j.cell.2023.01.012 snippet: RdrA and RdrB join to form a giant assembly up to 10 MDa notes: Duncan-Lowey et al. support RdrA/RdrB RADAR complex assembly. - subject: adenosine_substrate_deamination predicate: contributes to predicate_id: RO:0002326 object: inosine_nucleotide_accumulation description: RADAR-associated ATP-to-ITP deamination drives inosine-mononucleotide accumulation during phage infection. evidence: - reference: DOI:10.1016/j.cell.2023.01.012 snippet: RdrB catalyzes ATP-to-ITP conversion in vitro and induces the massive accumulation of inosine mononucleotides during phage infection in vivo notes: Duncan-Lowey et al. connect RdrB ATP-to-ITP catalysis to phage-infection-associated inosine mononucleotide accumulation. - subject: inosine_nucleotide_accumulation predicate: mitigates predicate_id: METPO:2007407 object: phage_replication description: RADAR-induced inosine nucleotide accumulation limits phage replication. evidence: - reference: DOI:10.1016/j.cell.2023.01.012 snippet: RdrB catalyzes ATP-to-ITP conversion in vitro and induces the massive accumulation of inosine mononucleotides during phage infection in vivo, limiting phage replication notes: Duncan-Lowey et al. support inosine mononucleotide accumulation as a phage-limiting RADAR output. - subject: adenosine_substrate_deamination predicate: confers predicate_id: METPO:2007700 object: radar_system_trait description: RADAR-mediated adenosine-nucleotide deamination realizes the RADAR antiphage phenotype. evidence: - reference: DOI:10.1016/j.cell.2023.01.012 snippet: rapid deamination of adenosine nucleotides is a key mediator of RADAR anti-phage defense notes: Duncan-Lowey et al. connect rapid adenosine-nucleotide deamination, rather than downstream inosine accumulation alone, to RADAR antiphage defense. - subject: radar_system_trait predicate: is a predicate_id: rdfs:subClassOf object: phage_defense_system description: RADAR system possession is a phage-defense-system trait. evidence: - reference: DOI:10.1016/j.cell.2023.01.012 snippet: RADAR is a two-protein bacterial defense system that was reported to defend against phage notes: Duncan-Lowey et al. support RADAR as a bacterial phage-defense system. discussions: - discussion_id: radar-trigger-and-substrate-gap prompt: Resolve RADAR phage triggers, RdrA activation, ATP-versus-RNA deamination, and inosine nucleotide toxicity before minting narrower RADAR mechanism children. kind: KNOWLEDGE_GAP status: OPEN rationale: 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. posed_by: codex posed_date: '2026-09-18' curation_history: - timestamp: '2026-09-18T09:55:00Z' curator: codex action: MINTED_TRAITMECH_ID changes: 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. llm_assisted: true - timestamp: '2026-09-18T10:07:00Z' curator: codex action: ADVERSARIAL_REVIEW_REPAIR changes: '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.' llm_assisted: true