identifier: traitmech:000354 label: Gao-Iet system definition: A phage defense system in which an organism possesses a Gao_Iet locus represented by DefenseFinder as a two-profile model requiring Gao_Iet__IetA and Gao_Iet__IetS. definition_source: DOI:10.1126/science.aba0372 trait_category: GENOMICS term_kind: CLASS mapping_status: PROPOSED parent_traits: - traitmech:000209 synonyms: - synonym_text: Gao_Iet synonym_type: RELATED_SYNONYM source: https://raw.githubusercontent.com/mdmparis/defense-finder-models/afb0e5a8b466be53586b13266f5d38d98c3ac268/List_system_article.md - synonym_text: Gao_Iet__IetA synonym_type: RELATED_SYNONYM source: https://raw.githubusercontent.com/mdmparis/defense-finder-models/afb0e5a8b466be53586b13266f5d38d98c3ac268/Liste_hmm_system.md - synonym_text: Gao_Iet__IetS synonym_type: RELATED_SYNONYM source: https://raw.githubusercontent.com/mdmparis/defense-finder-models/afb0e5a8b466be53586b13266f5d38d98c3ac268/Liste_hmm_system.md evidence: - reference: PMID:32855333 snippet: By systematic defense gene prediction and heterologous reconstitution, here we discover 29 widespread antiviral gene cassettes, collectively present in 32% of all sequenced bacterial and archaeal genomes, that mediate protection against specific bacteriophages. notes: Gao et al. support a systematic defense-gene prediction and heterologous reconstitution campaign that discovered widespread antiviral gene cassettes. - reference: https://raw.githubusercontent.com/mdmparis/defense-finder-models/afb0e5a8b466be53586b13266f5d38d98c3ac268/List_system_article.md snippet: Gao_Iet | 10\.1126/science\.aba0372 | Diverse enzymatic activities mediate antiviral immunity in prokaryotes notes: The DefenseFinder article registry maps the named Gao_Iet system to the Gao et al. prokaryotic antiviral-immunity paper. - reference: https://raw.githubusercontent.com/mdmparis/defense-finder-models/afb0e5a8b466be53586b13266f5d38d98c3ac268/DefenseFinder_rules.tsv snippet: "Gao_Iet\tGao_Iet\t2\t2\tGao_Iet__IetA, Gao_Iet__IetS" notes: The DefenseFinder rules table models Gao_Iet as a two-profile system requiring the Gao_Iet__IetA and Gao_Iet__IetS profiles. - reference: https://raw.githubusercontent.com/mdmparis/defense-finder-models/afb0e5a8b466be53586b13266f5d38d98c3ac268/Liste_hmm_system.md snippet: '| Gao_Iet__IetA | Gao_Iet__IetA | Gao_Iet | Custom | 100 |' notes: The DefenseFinder HMM inventory records Gao_Iet__IetA under Gao_Iet. - reference: https://raw.githubusercontent.com/mdmparis/defense-finder-models/afb0e5a8b466be53586b13266f5d38d98c3ac268/Liste_hmm_system.md snippet: '| Gao_Iet__IetS | Gao_Iet__IetS | Gao_Iet | Custom | 50 |' notes: The DefenseFinder HMM inventory records Gao_Iet__IetS under Gao_Iet. causal_graphs: - graph_id: gao_iet_locus_restricts_phage title: Gao-Iet loci confer bacterial phage defense description: Conservative system-level sketch linking possession of a Gao_Iet locus to Gao et al. antiviral cassette defense without asserting the unresolved IetA or IetS component activities. scope_status: NONMECHANISTIC scope_notes: The graph captures Gao-Iet as a named DefenseFinder two-profile Gao-family system while leaving natural hosts, IetA/IetS protein functions, phage triggers, and direct effector activity unresolved. nodes: - node_id: gao_iet_locus label: Gao_Iet locus node_type: GENETIC_ELEMENT description: A DefenseFinder Gao_Iet phage-defense locus represented by custom IetA and IetS profiles. - node_id: gao_2020_antiviral_cassette_defense label: Gao 2020 antiviral cassette defense node_type: BIOLOGICAL_PROCESS description: Bacteriophage protection by one of the antiviral gene cassettes described in the Gao et al. systematic defense-gene discovery campaign. - node_id: gao_iet_system_trait label: Gao-Iet system node_type: TRAIT grounding: traitmech:000354 description: Possession of a genome-encoded Gao-Iet 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: gao_iet_locus predicate: contributes to predicate_id: RO:0002326 object: gao_2020_antiviral_cassette_defense description: DefenseFinder maps Gao_Iet to the Gao et al. systematic antiphage-system discovery paper and models it as a two-profile system requiring IetA and IetS. evidence: - reference: PMID:32855333 snippet: By systematic defense gene prediction and heterologous reconstitution, here we discover 29 widespread antiviral gene cassettes, collectively present in 32% of all sequenced bacterial and archaeal genomes, that mediate protection against specific bacteriophages. notes: Gao et al. support bacteriophage protection by widespread antiviral gene cassettes. - reference: https://raw.githubusercontent.com/mdmparis/defense-finder-models/afb0e5a8b466be53586b13266f5d38d98c3ac268/List_system_article.md snippet: Gao_Iet | 10\.1126/science\.aba0372 | Diverse enzymatic activities mediate antiviral immunity in prokaryotes notes: The DefenseFinder article registry maps the named Gao_Iet system to the Gao et al. prokaryotic antiviral-immunity paper. - reference: https://raw.githubusercontent.com/mdmparis/defense-finder-models/afb0e5a8b466be53586b13266f5d38d98c3ac268/DefenseFinder_rules.tsv snippet: "Gao_Iet\tGao_Iet\t2\t2\tGao_Iet__IetA, Gao_Iet__IetS" notes: The DefenseFinder rules table models Gao_Iet as a two-profile system requiring the Gao_Iet__IetA and Gao_Iet__IetS profiles. - reference: https://raw.githubusercontent.com/mdmparis/defense-finder-models/afb0e5a8b466be53586b13266f5d38d98c3ac268/Liste_hmm_system.md snippet: '| Gao_Iet__IetA | Gao_Iet__IetA | Gao_Iet | Custom | 100 |' notes: The DefenseFinder HMM inventory records Gao_Iet__IetA under Gao_Iet. - reference: https://raw.githubusercontent.com/mdmparis/defense-finder-models/afb0e5a8b466be53586b13266f5d38d98c3ac268/Liste_hmm_system.md snippet: '| Gao_Iet__IetS | Gao_Iet__IetS | Gao_Iet | Custom | 50 |' notes: The DefenseFinder HMM inventory records Gao_Iet__IetS under Gao_Iet. - subject: gao_2020_antiviral_cassette_defense predicate: confers predicate_id: METPO:2007700 object: gao_iet_system_trait description: Gao_Iet-associated antiviral cassette defense realizes the Gao-Iet system trait. evidence: - reference: PMID:32855333 snippet: By systematic defense gene prediction and heterologous reconstitution, here we discover 29 widespread antiviral gene cassettes, collectively present in 32% of all sequenced bacterial and archaeal genomes, that mediate protection against specific bacteriophages. notes: Gao et al. support bacteriophage protection by widespread antiviral gene cassettes. - subject: gao_iet_system_trait predicate: is a predicate_id: rdfs:subClassOf object: phage_defense_system description: Gao-Iet system possession is a phage-defense-system trait. evidence: - reference: https://raw.githubusercontent.com/mdmparis/defense-finder-models/afb0e5a8b466be53586b13266f5d38d98c3ac268/List_system_article.md snippet: Gao_Iet | 10\.1126/science\.aba0372 | Diverse enzymatic activities mediate antiviral immunity in prokaryotes notes: The DefenseFinder article registry maps the named Gao_Iet system to the Gao et al. prokaryotic antiviral-immunity paper. - reference: https://raw.githubusercontent.com/mdmparis/defense-finder-models/afb0e5a8b466be53586b13266f5d38d98c3ac268/DefenseFinder_rules.tsv snippet: "Gao_Iet\tGao_Iet\t2\t2\tGao_Iet__IetA, Gao_Iet__IetS" notes: The DefenseFinder rules table models Gao_Iet as a two-profile system requiring the Gao_Iet__IetA and Gao_Iet__IetS profiles. discussions: - discussion_id: gao-iet-mechanism-gap prompt: Resolve Gao_Iet natural hosts, IetA/IetS component functions, phage triggers, and effector activity before minting narrower Gao_Iet mechanism children. kind: KNOWLEDGE_GAP status: OPEN rationale: Gao et al. support widespread antiviral gene cassettes that mediate protection against specific bacteriophages, and DefenseFinder models Gao_Iet as a two-profile system. The exact natural host breadth, Iet component identities, phage trigger, and profile-to-activity mapping remain unresolved. attaches_to: - causal_graphs#gao_iet_locus_restricts_phage posed_by: codex posed_date: '2026-09-22' curation_history: - timestamp: '2026-09-22T03:34:26Z' curator: codex action: MINTED_TRAITMECH_ID changes: Minted Gao-Iet system as a DOI-backed GENOMICS TraitRecord under phage defense system after an ignored-and-hidden duplicate review found no exact live TraitMech, METPO, history, or prior proposal record; the replacement placeholder is reserved in proposals/metpo_traitmech_v231. llm_assisted: true