identifier: traitmech:000268 label: Belenos system definition: A phage defense system in which an organism possesses a Belenos locus represented by a VCA0457 profile that can protect bacteria from bacteriophage infection. definition_source: DOI:10.1126/science.ads0768 trait_category: GENOMICS term_kind: CLASS mapping_status: PROPOSED parent_traits: - traitmech:000209 synonyms: - synonym_text: Belenos synonym_type: EXACT_SYNONYM source: https://raw.githubusercontent.com/mdmparis/defense-finder-models/afb0e5a8b466be53586b13266f5d38d98c3ac268/List_system_article.md - synonym_text: VCA0457 synonym_type: RELATED_SYNONYM source: https://raw.githubusercontent.com/mdmparis/defense-finder-models/afb0e5a8b466be53586b13266f5d38d98c3ac268/Liste_hmm_system.md evidence: - reference: DOI:10.1126/science.ads0768 snippet: nearly 10% of the integron cassettes in the pandemic Vibrio cholerae strain encode novel antiphage functions notes: Darracq et al. support treating the newly discovered Vibrio cholerae SCI antiphage cassettes as bacterial anti-phage systems. - reference: DOI:10.1126/science.ads0768 snippet: Most of these novel systems have little or no similarity to previously known ones, with several providing defense through cell lysis or growth arrest notes: Darracq et al. support a conservative system record that does not assert a resolved Belenos trigger, effector output, or universal pathway. - reference: https://raw.githubusercontent.com/mdmparis/defense-finder-models/afb0e5a8b466be53586b13266f5d38d98c3ac268/List_system_article.md snippet: Belenos | 10\.1126/science\.ads0768 | Sedentary chromosomal integrons as biobanks of bacterial antiphage defense systems notes: The DefenseFinder model registry maps the named Belenos system to the Darracq et al. SCI antiphage-system paper. - reference: https://raw.githubusercontent.com/mdmparis/defense-finder-models/afb0e5a8b466be53586b13266f5d38d98c3ac268/Liste_hmm_system.md snippet: Belenos__VCA0457 | | Belenos notes: The DefenseFinder HMM inventory records VCA0457 in the Belenos model namespace. causal_graphs: - graph_id: belenos_locus_restricts_phage title: Belenos loci confer bacterial phage defense description: Conservative system-level sketch linking possession of a Belenos locus to restricted bacteriophage propagation without asserting the unresolved phage trigger or molecular output. scope_status: NONMECHANISTIC scope_notes: The graph captures Belenos as a named SCI-derived anti-phage system with a VCA0457 DefenseFinder profile while leaving its phage trigger, molecular substrate, antiviral effector output, and subtype breadth unresolved. nodes: - node_id: belenos_locus label: Belenos locus node_type: GENETIC_ELEMENT description: A Belenos anti-phage defense locus represented in DefenseFinder by a VCA0457 profile. - node_id: restricted_phage_propagation label: restricted phage propagation node_type: BIOLOGICAL_PROCESS description: Reduced propagation of bacteriophage in cells carrying the Belenos system. - node_id: belenos_system_trait label: Belenos system node_type: TRAIT grounding: traitmech:000268 description: Possession of a genome-encoded Belenos 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: belenos_locus predicate: contributes to predicate_id: RO:0002326 object: restricted_phage_propagation description: DefenseFinder maps Belenos to an SCI anti-phage-system discovery paper and represents Belenos loci through the VCA0457 component profile. evidence: - reference: DOI:10.1126/science.ads0768 snippet: nearly 10% of the integron cassettes in the pandemic Vibrio cholerae strain encode novel antiphage functions notes: Darracq et al. describe the newly discovered antiphage-system cohort that the DefenseFinder Belenos registry row maps to the Belenos system. - reference: https://raw.githubusercontent.com/mdmparis/defense-finder-models/afb0e5a8b466be53586b13266f5d38d98c3ac268/Liste_hmm_system.md snippet: Belenos__VCA0457 | | Belenos notes: The DefenseFinder HMM inventory supports VCA0457 as the Belenos component profile. - subject: restricted_phage_propagation predicate: confers predicate_id: METPO:2007700 object: belenos_system_trait description: Belenos-mediated phage restriction realizes the Belenos system trait. evidence: - reference: DOI:10.1126/science.ads0768 snippet: Most of these novel systems have little or no similarity to previously known ones notes: Darracq et al. place the Belenos discovery cohort in a set of novel bacterial systems that protect against phages. - subject: belenos_system_trait predicate: is a predicate_id: rdfs:subClassOf object: phage_defense_system description: Belenos system possession is a phage-defense-system trait. evidence: - reference: https://raw.githubusercontent.com/mdmparis/defense-finder-models/afb0e5a8b466be53586b13266f5d38d98c3ac268/List_system_article.md snippet: Belenos | 10\.1126/science\.ads0768 | Sedentary chromosomal integrons as biobanks of bacterial antiphage defense systems notes: DefenseFinder associates Belenos with the Darracq et al. bacterial antiphage-system paper. discussions: - discussion_id: belenos-mechanism-gap prompt: Resolve Belenos phage triggers and effector outputs before minting narrower Belenos mechanism children. kind: KNOWLEDGE_GAP status: OPEN rationale: Darracq et al. and DefenseFinder support Belenos as a named anti-phage system with a VCA0457 profile, but the trigger, molecular substrate, antiviral effector output, and subtype-specific mechanism are not resolved enough here to assert a narrower mechanistic child trait. attaches_to: - causal_graphs#belenos_locus_restricts_phage posed_by: codex posed_date: '2026-09-19' curation_history: - timestamp: '2026-09-19T06:33:51Z' curator: codex action: MINTED_TRAITMECH_ID changes: Minted Belenos 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_v145. llm_assisted: true