identifier: traitmech:000298 label: Butters gp30-gp31 system definition: A phage defense system in which an organism possesses a Butters gp30-gp31 locus that can protect bacteria from bacteriophage infection. definition_source: DOI:10.1128/mSystems.00534-20 trait_category: GENOMICS term_kind: CLASS mapping_status: PROPOSED parent_traits: - traitmech:000209 synonyms: - synonym_text: Butters_gp30_gp31 synonym_type: RELATED_SYNONYM source: https://raw.githubusercontent.com/mdmparis/defense-finder-models/afb0e5a8b466be53586b13266f5d38d98c3ac268/List_system_article.md evidence: - reference: DOI:10.1128/mSystems.00534-20 snippet: we unveil a novel defense mechanism in cluster N prophage Butters notes: Mageeney et al. identify the Butters prophage as encoding a new heterotypic phage-defense mechanism. - reference: DOI:10.1128/mSystems.00534-20 snippet: we show that Butters genes located in the central region of the genome play a key role in the defense against heterotypic viral attack notes: Mageeney et al. support central Butters genes as contributors to prophage-mediated antiviral defense. - reference: DOI:10.1128/mSystems.00534-20 snippet: Our study suggests that a two-component system, articulated by interactions between protein products of genes 30 and 31, confers defense against heterotypic phage infection by PurpleHaze (cluster A/subcluster A3) or Alma (cluster A/subcluster A9) notes: Mageeney et al. connect Butters genes 30 and 31 to a two-component system that defends against PurpleHaze and Alma phage infection. - reference: https://raw.githubusercontent.com/mdmparis/defense-finder-models/afb0e5a8b466be53586b13266f5d38d98c3ac268/List_system_article.md snippet: Butters_gp30_gp31 | 10\.1128/mSystems\.00534-20 | Mycobacterium phage Butters-encoded proteins contribute to host defense against viral attack notes: The DefenseFinder model registry maps the named Butters_gp30_gp31 system to the Mageeney et al. Butters-defense paper. - reference: https://raw.githubusercontent.com/mdmparis/defense-finder-models/afb0e5a8b466be53586b13266f5d38d98c3ac268/Liste_hmm_system.md snippet: Butters_gp30_gp31__Butters_gp30 | Butters_gp30_gp31__Butters_gp30 | Butters_gp30_gp31 notes: The DefenseFinder HMM inventory records a Butters gp30-gp31 profile for Butters_gp30_gp31__Butters_gp30 in the Butters_gp30_gp31 model namespace. - reference: https://raw.githubusercontent.com/mdmparis/defense-finder-models/afb0e5a8b466be53586b13266f5d38d98c3ac268/Liste_hmm_system.md snippet: Butters_gp30_gp31__Butters_gp31 | Butters_gp30_gp31__Butters_gp31 | Butters_gp30_gp31 notes: The DefenseFinder HMM inventory records a Butters gp30-gp31 profile for Butters_gp30_gp31__Butters_gp31 in the Butters_gp30_gp31 model namespace. - reference: https://raw.githubusercontent.com/mdmparis/defense-finder-models/afb0e5a8b466be53586b13266f5d38d98c3ac268/DefenseFinder_rules.tsv snippet: "Butters_gp30_gp31\tButters_gp30_gp31\t2\t2\tButters_gp30_gp31__Butters_gp30,\ \ Butters_gp30_gp31__Butters_gp31" notes: The DefenseFinder rules table models Butters_gp30_gp31 as a two-component system requiring Butters_gp30 and Butters_gp31 profiles. causal_graphs: - graph_id: butters_gp30_gp31_locus_restricts_phage title: Butters gp30-gp31 loci confer heterotypic phage defense description: Conservative system-level sketch linking possession of a Butters gp30-gp31 locus to restricted bacteriophage propagation without asserting the unresolved phage trigger, gp31 modulatory role, or downstream arrest mechanism. scope_status: NONMECHANISTIC scope_notes: The graph captures Butters gp30-gp31 as a named anti-phage system with DefenseFinder Butters gp30 and gp31 profiles while leaving the direct phage trigger, the biochemical action of gp30, the modulatory role of gp31, and the Island3-targeting gp30-independent mechanism unresolved. nodes: - node_id: butters_gp30_gp31_locus label: Butters gp30-gp31 locus node_type: GENETIC_ELEMENT description: A Butters gp30-gp31 anti-phage defense locus cataloged in DefenseFinder with Butters gp30 and gp31 HMM profiles. - node_id: restricted_phage_propagation label: restricted phage propagation node_type: BIOLOGICAL_PROCESS description: Reduced propagation of bacteriophage in cells carrying the Butters gp30-gp31 system. - node_id: butters_gp30_gp31_system_trait label: Butters gp30-gp31 system node_type: TRAIT grounding: traitmech:000298 description: Possession of a genome-encoded Butters gp30-gp31 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: butters_gp30_gp31_locus predicate: contributes to predicate_id: RO:0002326 object: restricted_phage_propagation description: Mageeney et al. show that Butters genes in the central genome region contribute to defense against heterotypic viral attack, and DefenseFinder catalogs Butters_gp30 and Butters_gp31 profiles in the Butters_gp30_gp31 model namespace. evidence: - reference: DOI:10.1128/mSystems.00534-20 snippet: we show that Butters genes located in the central region of the genome play a key role in the defense against heterotypic viral attack notes: Mageeney et al. support Butters central genes as effectors of heterotypic viral defense. - reference: https://raw.githubusercontent.com/mdmparis/defense-finder-models/afb0e5a8b466be53586b13266f5d38d98c3ac268/Liste_hmm_system.md snippet: Butters_gp30_gp31__Butters_gp30 | Butters_gp30_gp31__Butters_gp30 | Butters_gp30_gp31 notes: The DefenseFinder HMM inventory records a Butters gp30-gp31 profile for Butters_gp30_gp31__Butters_gp30 in the Butters_gp30_gp31 model namespace. - reference: https://raw.githubusercontent.com/mdmparis/defense-finder-models/afb0e5a8b466be53586b13266f5d38d98c3ac268/Liste_hmm_system.md snippet: Butters_gp30_gp31__Butters_gp31 | Butters_gp30_gp31__Butters_gp31 | Butters_gp30_gp31 notes: The DefenseFinder HMM inventory records a Butters gp30-gp31 profile for Butters_gp30_gp31__Butters_gp31 in the Butters_gp30_gp31 model namespace. - reference: https://raw.githubusercontent.com/mdmparis/defense-finder-models/afb0e5a8b466be53586b13266f5d38d98c3ac268/DefenseFinder_rules.tsv snippet: "Butters_gp30_gp31\tButters_gp30_gp31\t2\t2\tButters_gp30_gp31__Butters_gp30,\ \ Butters_gp30_gp31__Butters_gp31" notes: The DefenseFinder rules table models Butters_gp30_gp31 as a two-component system requiring Butters_gp30 and Butters_gp31 profiles. - subject: restricted_phage_propagation predicate: confers predicate_id: METPO:2007700 object: butters_gp30_gp31_system_trait description: Butters-gp30-gp31-associated restriction of phage propagation realizes the Butters gp30-gp31 system trait. evidence: - reference: DOI:10.1128/mSystems.00534-20 snippet: Our study suggests that a two-component system, articulated by interactions between protein products of genes 30 and 31, confers defense against heterotypic phage infection by PurpleHaze (cluster A/subcluster A3) or Alma (cluster A/subcluster A9) notes: Mageeney et al. support Butters gp30 and gp31 as a two-component system that can defend against PurpleHaze or Alma infection. - reference: https://raw.githubusercontent.com/mdmparis/defense-finder-models/afb0e5a8b466be53586b13266f5d38d98c3ac268/List_system_article.md snippet: Butters_gp30_gp31 | 10\.1128/mSystems\.00534-20 | Mycobacterium phage Butters-encoded proteins contribute to host defense against viral attack notes: DefenseFinder records Butters_gp30_gp31 as a named system from the Mageeney et al. Butters-defense paper. - subject: butters_gp30_gp31_system_trait predicate: is a predicate_id: rdfs:subClassOf object: phage_defense_system description: Butters gp30-gp31 system possession is a phage-defense-system trait. evidence: - reference: https://raw.githubusercontent.com/mdmparis/defense-finder-models/afb0e5a8b466be53586b13266f5d38d98c3ac268/List_system_article.md snippet: '| Butters_gp30_gp31 | 10\.1128/mSystems\.00534-20 | Mycobacterium phage Butters-encoded proteins contribute to host defense against viral attack |' notes: DefenseFinder associates Butters_gp30_gp31 with the Mageeney et al. Butters viral-defense paper. discussions: - discussion_id: butters_gp30_gp31-mechanism-gap prompt: Resolve the Butters gp30 biochemical output, the gp31 modulatory role, the gp30-gp31 stoichiometry, the direct PurpleHaze or Alma trigger, the Island3 gp30-independent defense, and homolog breadth before minting narrower Butters gp30-gp31 mechanism children. kind: KNOWLEDGE_GAP status: OPEN rationale: Mageeney et al. and DefenseFinder support Butters gp30-gp31 as a named anti-phage system with Butters gp30 and gp31 profiles, but the direct phage trigger, gp30 biochemical output, gp31 modulatory activity, stoichiometry of the possible gp30-gp31 complex, gp30-independent Island3-targeting defense, and relationship to CarolAnn and Sbash homologous systems are not resolved enough here to assert a narrower mechanistic child trait. attaches_to: - causal_graphs#butters_gp30_gp31_locus_restricts_phage posed_by: codex posed_date: '2026-09-20' curation_history: - timestamp: '2026-09-20T01:32:52Z' curator: codex action: MINTED_TRAITMECH_ID changes: Minted Butters gp30-gp31 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_v175. llm_assisted: true