identifier: traitmech:000541 label: DRT8 system definition: A DRT system in which an organism possesses a genome-encoded DefenseFinder DRT8 subtype locus represented by a mandatory DRT8__DRT8 profile, optionally accompanied by the DRT8__DRT8b accessory profile. definition_source: https://raw.githubusercontent.com/mdmparis/defense-finder-models/afb0e5a8b466be53586b13266f5d38d98c3ac268/DefenseFinder_rules.tsv trait_category: GENOMICS term_kind: CLASS mapping_status: PROPOSED parent_traits: - traitmech:000279 synonyms: - synonym_text: DRT8 synonym_type: RELATED_SYNONYM source: https://raw.githubusercontent.com/mdmparis/defense-finder-models/afb0e5a8b466be53586b13266f5d38d98c3ac268/DefenseFinder_rules.tsv - synonym_text: DRT8__DRT8 synonym_type: RELATED_SYNONYM source: https://raw.githubusercontent.com/mdmparis/defense-finder-models/afb0e5a8b466be53586b13266f5d38d98c3ac268/Liste_hmm_system.md - synonym_text: DRT8__DRT8b synonym_type: RELATED_SYNONYM source: https://raw.githubusercontent.com/mdmparis/defense-finder-models/afb0e5a8b466be53586b13266f5d38d98c3ac268/Liste_hmm_system.md evidence: - reference: DOI:10.1126/science.aba0372 snippet: We discovered that a family of uncharacterized reverse transcriptases (RTs) are active defense systems notes: Gao et al. experimentally support defense-associated reverse transcriptases as active antiphage systems. - reference: DOI:10.1126/science.aba0372 snippet: We named these genes defense-associated RTs (DRTs) notes: Gao et al. coined the defense-associated RT naming that underlies the DRT system family. - reference: DOI:10.1126/science.aba0372 snippet: In all cases, mutations in the RT active site [(Y/F)xDD to (Y/F)xAA, where x is any amino acid] abolished activity notes: Gao et al. connect DRT antiphage activity to conserved reverse-transcriptase active-site residues. - reference: https://raw.githubusercontent.com/mdmparis/defense-finder-models/afb0e5a8b466be53586b13266f5d38d98c3ac268/List_system_article.md snippet: '| DRT | 10\.1126/science\.aba0372 | Diverse enzymatic activities mediate antiviral immunity in prokaryotes | ' notes: The pinned DefenseFinder article registry maps the DRT source key to the Gao et al. prokaryotic antiviral-immunity paper. - reference: https://raw.githubusercontent.com/mdmparis/defense-finder-models/afb0e5a8b466be53586b13266f5d38d98c3ac268/Liste_hmm_system.md snippet: '| DRT8__DRT8 | DRT8__DRT8 | DRT8 | Custom | 200 | | DRT8__DRT8a | | DRT8 | Custom | 250 | | DRT8__DRT8b | DRT8__DRT8b | DRT8 | Custom | 50 |' notes: The pinned DefenseFinder HMM inventory records DRT8__DRT8, DRT8__DRT8a, and DRT8__DRT8b under the DRT8 model namespace, with DRT8__DRT8a lacking an emitted HMM name. - reference: https://raw.githubusercontent.com/mdmparis/defense-finder-models/afb0e5a8b466be53586b13266f5d38d98c3ac268/DefenseFinder_rules.tsv snippet: "DRT\tDRT8\t1\t1\tDRT8__DRT8\tDRT8__DRT8b\t\t" notes: The pinned DefenseFinder rules table models DRT8 as a DRT subsystem requiring DRT8__DRT8 and optionally admitting DRT8__DRT8b as accessory. causal_graphs: - graph_id: drt8_locus_reverse_transcriptase_defense title: DRT8 loci support DRT antiphage defense description: Conservative system-level sketch linking a DRT8 locus to reverse-transcriptase-dependent DRT phage defense and DRT8 system possession. scope_status: NONMECHANISTIC scope_notes: The graph captures DRT8 at DefenseFinder subtype-locus level without asserting the direct DRT8 reverse-transcriptase product, phage trigger, native host breadth, sensitive phage breadth, the DRT8__DRT8b accessory role, why the DRT8__DRT8a HMM inventory row has no emitted HMM name or rule membership, or whether every DefenseFinder DRT8 prediction is a complete experimentally active DRT8 locus. nodes: - node_id: drt8_locus label: DRT8 locus node_type: GENETIC_ELEMENT description: A defense-associated reverse transcriptase subtype VIII locus represented in DefenseFinder by DRT8 rule profiles. - node_id: drt_rt_active_site_activity label: DRT reverse-transcriptase active-site activity node_type: MOLECULAR_FUNCTION description: Reverse-transcriptase active-site-dependent activity of a defense-associated RT antiphage protein. - node_id: drt8_system_trait label: DRT8 system node_type: TRAIT grounding: traitmech:000541 description: Possession of a genome-encoded DRT8 phage-defense system. - node_id: drt_system_trait label: DRT system node_type: TRAIT grounding: traitmech:000279 description: Possession of a genome-encoded defense-associated reverse transcriptase phage-defense system. edges: - subject: drt8_locus predicate: contributes to predicate_id: RO:0002326 object: drt_rt_active_site_activity description: DRT8 loci are represented in DefenseFinder by custom defense-associated reverse transcriptase profiles. evidence: - reference: DOI:10.1126/science.aba0372 snippet: We named these genes defense-associated RTs (DRTs) notes: Gao et al. coined the defense-associated RT naming that underlies the DRT system family. - reference: https://raw.githubusercontent.com/mdmparis/defense-finder-models/afb0e5a8b466be53586b13266f5d38d98c3ac268/Liste_hmm_system.md snippet: '| DRT8__DRT8 | DRT8__DRT8 | DRT8 | Custom | 200 | | DRT8__DRT8a | | DRT8 | Custom | 250 | | DRT8__DRT8b | DRT8__DRT8b | DRT8 | Custom | 50 |' notes: The pinned DefenseFinder HMM inventory records DRT8__DRT8, DRT8__DRT8a, and DRT8__DRT8b under the DRT8 model namespace, with DRT8__DRT8a lacking an emitted HMM name. - subject: drt_rt_active_site_activity predicate: confers predicate_id: METPO:2007700 object: drt8_system_trait description: The first-pass DRT8 system trait is realized by a DefenseFinder DRT8 subtype locus within the reverse-transcriptase-dependent DRT family. evidence: - reference: DOI:10.1126/science.aba0372 snippet: We discovered that a family of uncharacterized reverse transcriptases (RTs) are active defense systems notes: Gao et al. experimentally support defense-associated reverse transcriptases as active antiphage systems. - reference: DOI:10.1126/science.aba0372 snippet: In all cases, mutations in the RT active site [(Y/F)xDD to (Y/F)xAA, where x is any amino acid] abolished activity notes: Gao et al. connect DRT antiphage activity to conserved reverse-transcriptase active-site residues. - reference: https://raw.githubusercontent.com/mdmparis/defense-finder-models/afb0e5a8b466be53586b13266f5d38d98c3ac268/DefenseFinder_rules.tsv snippet: "DRT\tDRT8\t1\t1\tDRT8__DRT8\tDRT8__DRT8b\t\t" notes: The pinned DefenseFinder rules table models DRT8 as a DRT subsystem requiring DRT8__DRT8 and optionally admitting DRT8__DRT8b as accessory. - subject: drt8_system_trait predicate: is a predicate_id: rdfs:subClassOf object: drt_system_trait description: DRT8 system possession is a DRT-system trait. evidence: - reference: https://raw.githubusercontent.com/mdmparis/defense-finder-models/afb0e5a8b466be53586b13266f5d38d98c3ac268/List_system_article.md snippet: '| DRT | 10\.1126/science\.aba0372 | Diverse enzymatic activities mediate antiviral immunity in prokaryotes | ' notes: The pinned DefenseFinder article registry maps the DRT source key to the Gao et al. prokaryotic antiviral-immunity paper. - reference: https://raw.githubusercontent.com/mdmparis/defense-finder-models/afb0e5a8b466be53586b13266f5d38d98c3ac268/DefenseFinder_rules.tsv snippet: "DRT\tDRT8\t1\t1\tDRT8__DRT8\tDRT8__DRT8b\t\t" notes: The pinned DefenseFinder rules table models DRT8 as a DRT subsystem requiring DRT8__DRT8 and optionally admitting DRT8__DRT8b as accessory. discussions: - discussion_id: drt8-profile-activity-gap prompt: Resolve the DRT8 reverse-transcriptase product, direct phage trigger, host breadth, DRT8__DRT8b accessory role, and DRT8__DRT8a HMM-row status before minting DRT8 mechanism or component children. kind: KNOWLEDGE_GAP status: OPEN rationale: Gao et al. support defense-associated reverse transcriptases as a broad antiphage-system family, and the pinned DefenseFinder HMM inventory and rules table support DRT8 as a DRT subsystem with a mandatory DRT8__DRT8 profile and an accessory DRT8__DRT8b profile. This first-pass record leaves the exact DRT8 RT product, phage trigger, host breadth, DRT8__DRT8b accessory role, and DRT8__DRT8a inventory-row status unresolved. evidence: - reference: DOI:10.1126/science.aba0372 snippet: We discovered that a family of uncharacterized reverse transcriptases (RTs) are active defense systems notes: Gao et al. experimentally support defense-associated reverse transcriptases as active antiphage systems. - reference: DOI:10.1126/science.aba0372 snippet: In all cases, mutations in the RT active site [(Y/F)xDD to (Y/F)xAA, where x is any amino acid] abolished activity notes: Gao et al. connect DRT antiphage activity to conserved reverse-transcriptase active-site residues. - reference: https://raw.githubusercontent.com/mdmparis/defense-finder-models/afb0e5a8b466be53586b13266f5d38d98c3ac268/Liste_hmm_system.md snippet: '| DRT8__DRT8 | DRT8__DRT8 | DRT8 | Custom | 200 | | DRT8__DRT8a | | DRT8 | Custom | 250 | | DRT8__DRT8b | DRT8__DRT8b | DRT8 | Custom | 50 |' notes: The pinned DefenseFinder HMM inventory records DRT8__DRT8, DRT8__DRT8a, and DRT8__DRT8b under the DRT8 model namespace, with DRT8__DRT8a lacking an emitted HMM name. - reference: https://raw.githubusercontent.com/mdmparis/defense-finder-models/afb0e5a8b466be53586b13266f5d38d98c3ac268/DefenseFinder_rules.tsv snippet: "DRT\tDRT8\t1\t1\tDRT8__DRT8\tDRT8__DRT8b\t\t" notes: The pinned DefenseFinder rules table models DRT8 as a DRT subsystem requiring DRT8__DRT8 and optionally admitting DRT8__DRT8b as accessory. attaches_to: - causal_graphs#drt8_locus_reverse_transcriptase_defense posed_by: codex posed_date: '2026-10-02' curation_history: - timestamp: '2026-10-02T09:37:24Z' curator: codex action: MINTED_TRAITMECH_ID changes: Minted DRT8 system as a DOI- and DefenseFinder-backed GENOMICS TraitRecord under the DRT system parent 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_v418. llm_assisted: true - timestamp: '2026-10-02T09:37:25Z' curator: codex action: REVIEW_CANONICAL_EXAMPLE_EVIDENCE_GAP changes: Reviewed DRT8 system during initial curation and left canonical_examples empty because Gao et al. and the pinned DefenseFinder tables support the DRT family and the DRT8 model namespace but not an accession-backed native microbial taxon exemplar tied to DRT8__DRT8 or DRT8__DRT8b and experimentally verified endogenous DRT8 activity. No paid research was used. llm_assisted: true