identifier: traitmech:000414 label: SNIPE system definition: A phage defense system in which an organism possesses a SNIPE anti-bacteriophage system that localizes to the bacterial membrane, exploits the spatial organization of phage genome injection, and directly cleaves incoming phage DNA to block siphovirus infection. definition_source: DOI:10.1038/s41586-026-10207-1 trait_category: GENOMICS term_kind: CLASS mapping_status: PROPOSED parent_traits: - traitmech:000209 synonyms: - synonym_text: SNIPE synonym_type: EXACT_SYNONYM source: DOI:10.1038/s41586-026-10207-1 evidence: - reference: DOI:10.1038/s41586-026-10207-1 snippet: Here, we characterize SNIPE, an anti-bacteriophage defence system that constitutively localizes to the bacterial cell membrane in Escherichia coli notes: Saxton et al. define SNIPE as an anti-bacteriophage defence system and localize it to the bacterial cell membrane in Escherichia coli. - reference: DOI:10.1038/s41586-026-10207-1 snippet: Using radiolabelled phage DNA and time-lapse microscopy to track phage genomes, we demonstrate that SNIPE directly cleaves phage DNA during genome injection. notes: Saxton et al. show that SNIPE directly cleaves phage DNA while the phage genome is being injected. - reference: DOI:10.1038/s41586-026-10207-1 snippet: SNIPE also defends against diverse siphoviruses notes: Saxton et al. support SNIPE defence against diverse siphoviruses. - reference: DOI:10.1038/s41586-026-10207-1 snippet: Our findings establish SNIPE as a widespread bacterial defence system that exploits the spatial organization of phage genome injection to specifically target viral DNA notes: Saxton et al. frame SNIPE as a widespread defence system that exploits phage genome-injection geometry to target viral DNA. - reference: https://raw.githubusercontent.com/mdmparis/defense-finder-models/afb0e5a8b466be53586b13266f5d38d98c3ac268/List_system_article.md snippet: '| SNIPE | 10\.1038/s41586-026-10207-1 | A membrane-bound nuclease directly cleaves phage DNA during genome injection |' notes: The pinned DefenseFinder article registry maps the named SNIPE system to the Saxton et al. phage-genome-injection cleavage paper. The pinned HMM inventory and rules table do not list SNIPE, so this row is name-to-paper evidence rather than model-component evidence. causal_graphs: - graph_id: snipe_cleaves_injected_phage_dna title: SNIPE cleaves phage DNA during genome injection description: Conservative system-level sketch linking a SNIPE locus to direct phage DNA cleavage during genome injection, inhibition of siphovirus infection, and SNIPE system possession. scope_status: NONMECHANISTIC scope_notes: The graph captures SNIPE at membrane-localized phage-genome-injection targeting level without asserting the exact direct viral sensor, the full host or phage range, or any DefenseFinder HMM-to-component mapping. nodes: - node_id: snipe_locus label: SNIPE locus node_type: GENETIC_ELEMENT description: A SNIPE anti-bacteriophage locus encoding the membrane-localized SNIPE defense activity. - node_id: snipe_direct_phage_dna_cleavage label: SNIPE direct phage DNA cleavage node_type: BIOLOGICAL_PROCESS description: Direct cleavage of phage DNA by SNIPE as the viral genome is injected. - node_id: phage_genome_injection label: phage genome injection node_type: BIOLOGICAL_PROCESS description: Injection of a siphovirus genome into the bacterial cell. - node_id: siphovirus_infection label: siphovirus infection node_type: BIOLOGICAL_PROCESS description: Productive infection by bacteriophages with siphovirus morphology. - node_id: snipe_system_trait label: SNIPE system node_type: TRAIT grounding: traitmech:000414 description: Possession of a genome-encoded SNIPE 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: snipe_locus predicate: enables predicate_id: RO:0002327 object: snipe_direct_phage_dna_cleavage description: A SNIPE locus enables direct cleavage of phage DNA during genome injection. evidence: - reference: DOI:10.1038/s41586-026-10207-1 snippet: Using radiolabelled phage DNA and time-lapse microscopy to track phage genomes, we demonstrate that SNIPE directly cleaves phage DNA during genome injection. notes: Saxton et al. directly connect SNIPE to phage DNA cleavage during genome injection. - subject: snipe_direct_phage_dna_cleavage predicate: mitigates predicate_id: METPO:2007407 object: phage_genome_injection description: SNIPE targets viral DNA during the genome-injection stage of phage infection. evidence: - reference: DOI:10.1038/s41586-026-10207-1 snippet: Our findings establish SNIPE as a widespread bacterial defence system that exploits the spatial organization of phage genome injection to specifically target viral DNA notes: Saxton et al. frame SNIPE cleavage as exploitation of the spatial organization of phage genome injection. - subject: snipe_direct_phage_dna_cleavage predicate: mitigates predicate_id: METPO:2007407 object: siphovirus_infection description: By targeting injected viral DNA, SNIPE restricts siphovirus infection. evidence: - reference: DOI:10.1038/s41586-026-10207-1 snippet: SNIPE also defends against diverse siphoviruses notes: Saxton et al. support SNIPE-mediated defence against diverse siphoviruses. - subject: snipe_direct_phage_dna_cleavage predicate: confers predicate_id: METPO:2007700 object: snipe_system_trait description: Direct cleavage of injected phage DNA realizes the SNIPE system trait. evidence: - reference: DOI:10.1038/s41586-026-10207-1 snippet: Using radiolabelled phage DNA and time-lapse microscopy to track phage genomes, we demonstrate that SNIPE directly cleaves phage DNA during genome injection. notes: Saxton et al. show the SNIPE phage-defense output as direct phage DNA cleavage during genome injection. - subject: snipe_system_trait predicate: is a predicate_id: rdfs:subClassOf object: phage_defense_system description: SNIPE system possession is a phage-defense-system trait. evidence: - reference: DOI:10.1038/s41586-026-10207-1 snippet: Here, we characterize SNIPE, an anti-bacteriophage defence system that constitutively localizes to the bacterial cell membrane in Escherichia coli notes: Saxton et al. define SNIPE as an anti-bacteriophage defence system. - reference: https://raw.githubusercontent.com/mdmparis/defense-finder-models/afb0e5a8b466be53586b13266f5d38d98c3ac268/List_system_article.md snippet: '| SNIPE | 10\.1038/s41586-026-10207-1 | A membrane-bound nuclease directly cleaves phage DNA during genome injection |' notes: The pinned DefenseFinder article registry maps the named SNIPE system to the Saxton et al. phage-genome-injection cleavage paper. The pinned HMM inventory and rules table do not list SNIPE, so this row is name-to-paper evidence rather than model-component evidence. discussions: - discussion_id: snipe-defensefinder-model-gap prompt: Resolve SNIPE host breadth, sensitive-phage breadth, direct tape-measure interaction specificity, and DefenseFinder HMM/rules coverage before minting narrower SNIPE mechanism children. kind: KNOWLEDGE_GAP status: OPEN rationale: Saxton et al. support SNIPE as a membrane-localized anti-bacteriophage system that directly cleaves phage DNA during genome injection, while the pinned DefenseFinder article registry names a SNIPE system. The pinned DefenseFinder HMM inventory and rules table have no SNIPE rows, and the evidence does not yet resolve full host breadth, full target-phage breadth, direct tape-measure protein specificity, or profile-to-activity modeling. evidence: - reference: DOI:10.1038/s41586-026-10207-1 snippet: Our findings establish SNIPE as a widespread bacterial defence system that exploits the spatial organization of phage genome injection to specifically target viral DNA notes: Saxton et al. support SNIPE as a widespread phage-defense system targeting viral DNA during phage genome injection. - reference: https://raw.githubusercontent.com/mdmparis/defense-finder-models/afb0e5a8b466be53586b13266f5d38d98c3ac268/List_system_article.md snippet: '| SNIPE | 10\.1038/s41586-026-10207-1 | A membrane-bound nuclease directly cleaves phage DNA during genome injection |' notes: The pinned DefenseFinder article registry maps the named SNIPE system to the Saxton et al. phage-genome-injection cleavage paper. The pinned HMM inventory and rules table do not list SNIPE, so this row is name-to-paper evidence rather than model-component evidence. - reference: https://raw.githubusercontent.com/mdmparis/defense-finder-models/afb0e5a8b466be53586b13266f5d38d98c3ac268/Liste_hmm_system.md notes: The pinned DefenseFinder HMM inventory does not list SNIPE, leaving profile-level components unresolved. - reference: https://raw.githubusercontent.com/mdmparis/defense-finder-models/afb0e5a8b466be53586b13266f5d38d98c3ac268/DefenseFinder_rules.tsv notes: The pinned DefenseFinder rules table does not list SNIPE, leaving rule-level detection criteria unresolved. attaches_to: - causal_graphs#snipe_cleaves_injected_phage_dna posed_by: codex posed_date: '2026-09-27' curation_history: - timestamp: '2026-09-27T18:23:52Z' curator: codex action: MINTED_TRAITMECH_ID changes: Minted SNIPE 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; kept the graph at membrane-localized phage-genome-injection cleavage level because the pinned DefenseFinder article row is not backed by pinned HMM or rules rows; the replacement placeholder is reserved in proposals/metpo_traitmech_v291. llm_assisted: true - timestamp: '2026-09-27T18:23:53Z' curator: codex action: REVIEW_CANONICAL_EXAMPLE_EVIDENCE_GAP changes: Reviewed SNIPE system during canonical-example issue 444 enforcement and left canonical_examples empty because the sources support E. coli expression and phage-challenge assays plus a DefenseFinder article-registry system name, but not a direct native microbial isolate exemplar with experimentally verified SNIPE activity. No paid research was used. llm_assisted: true