identifier: traitmech:000359 label: Gao-Qat system definition: A phage defense system in which an organism possesses a Gao_Qat locus represented by DefenseFinder as a four-profile model requiring Gao_Qat__QatA, Gao_Qat__QatB, Gao_Qat__QatC, and Gao_Qat__QatD. definition_source: DOI:10.1126/science.aba0372 trait_category: GENOMICS term_kind: CLASS mapping_status: PROPOSED parent_traits: - traitmech:000209 synonyms: - synonym_text: Gao_Qat synonym_type: RELATED_SYNONYM source: https://raw.githubusercontent.com/mdmparis/defense-finder-models/afb0e5a8b466be53586b13266f5d38d98c3ac268/List_system_article.md - synonym_text: Gao_Qat__QatA synonym_type: RELATED_SYNONYM source: https://raw.githubusercontent.com/mdmparis/defense-finder-models/afb0e5a8b466be53586b13266f5d38d98c3ac268/Liste_hmm_system.md - synonym_text: Gao_Qat__QatB synonym_type: RELATED_SYNONYM source: https://raw.githubusercontent.com/mdmparis/defense-finder-models/afb0e5a8b466be53586b13266f5d38d98c3ac268/Liste_hmm_system.md - synonym_text: Gao_Qat__QatC synonym_type: RELATED_SYNONYM source: https://raw.githubusercontent.com/mdmparis/defense-finder-models/afb0e5a8b466be53586b13266f5d38d98c3ac268/Liste_hmm_system.md - synonym_text: Gao_Qat__QatD 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_Qat | 10\.1126/science\.aba0372 | Diverse enzymatic activities mediate antiviral immunity in prokaryotes notes: The DefenseFinder article registry maps the named Gao_Qat 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_Qat\tGao_Qat\t4\t4\tGao_Qat__QatA, Gao_Qat__QatB, Gao_Qat__QatC, Gao_Qat__QatD" notes: The DefenseFinder rules table models Gao_Qat as a four-profile system requiring the Gao_Qat__QatA through Gao_Qat__QatD profiles. - reference: https://raw.githubusercontent.com/mdmparis/defense-finder-models/afb0e5a8b466be53586b13266f5d38d98c3ac268/Liste_hmm_system.md snippet: '| Gao_Qat__QatA | Gao_Qat__QatA | Gao_Qat | Custom | 20 |' notes: The DefenseFinder HMM inventory records Gao_Qat__QatA under Gao_Qat. - reference: https://raw.githubusercontent.com/mdmparis/defense-finder-models/afb0e5a8b466be53586b13266f5d38d98c3ac268/Liste_hmm_system.md snippet: '| Gao_Qat__QatB | Gao_Qat__QatB | Gao_Qat | Custom | 20 |' notes: The DefenseFinder HMM inventory records Gao_Qat__QatB under Gao_Qat. - reference: https://raw.githubusercontent.com/mdmparis/defense-finder-models/afb0e5a8b466be53586b13266f5d38d98c3ac268/Liste_hmm_system.md snippet: '| Gao_Qat__QatC | Gao_Qat__QatC | Gao_Qat | Custom | 20 |' notes: The DefenseFinder HMM inventory records Gao_Qat__QatC under Gao_Qat. - reference: https://raw.githubusercontent.com/mdmparis/defense-finder-models/afb0e5a8b466be53586b13266f5d38d98c3ac268/Liste_hmm_system.md snippet: '| Gao_Qat__QatD | Gao_Qat__QatD | Gao_Qat | Custom | 20 |' notes: The DefenseFinder HMM inventory records Gao_Qat__QatD under Gao_Qat. causal_graphs: - graph_id: gao_qat_locus_restricts_phage title: Gao-Qat loci confer bacterial phage defense description: Conservative system-level sketch linking possession of a Gao_Qat locus to Gao et al. antiviral cassette defense without asserting the unresolved Qat component activities. scope_status: NONMECHANISTIC scope_notes: The graph captures Gao-Qat as a named DefenseFinder four-profile Gao-family system while leaving natural hosts, QatA/QatB/QatC/QatD protein functions, phage triggers, and direct effector activity unresolved. nodes: - node_id: gao_qat_locus label: Gao_Qat locus node_type: GENETIC_ELEMENT description: A DefenseFinder Gao_Qat phage-defense locus represented by custom QatA through QatD 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_qat_system_trait label: Gao-Qat system node_type: TRAIT grounding: traitmech:000359 description: Possession of a genome-encoded Gao-Qat 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_qat_locus predicate: contributes to predicate_id: RO:0002326 object: gao_2020_antiviral_cassette_defense description: DefenseFinder maps Gao_Qat to the Gao et al. systematic antiphage-system discovery paper and models it as a four-profile system requiring QatA through QatD. 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_Qat | 10\.1126/science\.aba0372 | Diverse enzymatic activities mediate antiviral immunity in prokaryotes notes: The DefenseFinder article registry maps the named Gao_Qat 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_Qat\tGao_Qat\t4\t4\tGao_Qat__QatA, Gao_Qat__QatB, Gao_Qat__QatC,\ \ Gao_Qat__QatD" notes: The DefenseFinder rules table models Gao_Qat as a four-profile system requiring the Gao_Qat__QatA through Gao_Qat__QatD profiles. - reference: https://raw.githubusercontent.com/mdmparis/defense-finder-models/afb0e5a8b466be53586b13266f5d38d98c3ac268/Liste_hmm_system.md snippet: '| Gao_Qat__QatA | Gao_Qat__QatA | Gao_Qat | Custom | 20 |' notes: The DefenseFinder HMM inventory records Gao_Qat__QatA under Gao_Qat. - reference: https://raw.githubusercontent.com/mdmparis/defense-finder-models/afb0e5a8b466be53586b13266f5d38d98c3ac268/Liste_hmm_system.md snippet: '| Gao_Qat__QatB | Gao_Qat__QatB | Gao_Qat | Custom | 20 |' notes: The DefenseFinder HMM inventory records Gao_Qat__QatB under Gao_Qat. - reference: https://raw.githubusercontent.com/mdmparis/defense-finder-models/afb0e5a8b466be53586b13266f5d38d98c3ac268/Liste_hmm_system.md snippet: '| Gao_Qat__QatC | Gao_Qat__QatC | Gao_Qat | Custom | 20 |' notes: The DefenseFinder HMM inventory records Gao_Qat__QatC under Gao_Qat. - reference: https://raw.githubusercontent.com/mdmparis/defense-finder-models/afb0e5a8b466be53586b13266f5d38d98c3ac268/Liste_hmm_system.md snippet: '| Gao_Qat__QatD | Gao_Qat__QatD | Gao_Qat | Custom | 20 |' notes: The DefenseFinder HMM inventory records Gao_Qat__QatD under Gao_Qat. - subject: gao_2020_antiviral_cassette_defense predicate: confers predicate_id: METPO:2007700 object: gao_qat_system_trait description: Gao_Qat-associated antiviral cassette defense realizes the Gao-Qat 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_qat_system_trait predicate: is a predicate_id: rdfs:subClassOf object: phage_defense_system description: Gao-Qat 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_Qat | 10\.1126/science\.aba0372 | Diverse enzymatic activities mediate antiviral immunity in prokaryotes notes: The DefenseFinder article registry maps the named Gao_Qat 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_Qat\tGao_Qat\t4\t4\tGao_Qat__QatA, Gao_Qat__QatB, Gao_Qat__QatC,\ \ Gao_Qat__QatD" notes: The DefenseFinder rules table models Gao_Qat as a four-profile system requiring the Gao_Qat__QatA through Gao_Qat__QatD profiles. discussions: - discussion_id: gao-qat-mechanism-gap prompt: Resolve Gao_Qat natural hosts, Qat component functions, phage triggers, and effector activity before minting narrower Gao_Qat 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_Qat as a four-profile system. The exact natural host breadth, QatA/QatB/QatC/QatD component identities, phage trigger, and profile-to-activity mapping remain unresolved. attaches_to: - causal_graphs#gao_qat_locus_restricts_phage posed_by: codex posed_date: '2026-09-22' curation_history: - timestamp: '2026-09-22T08:09:38Z' curator: codex action: MINTED_TRAITMECH_ID changes: Minted Gao-Qat 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_v236. llm_assisted: true