identifier: traitmech:000299 label: Butters gp57r system definition: A phage defense system in which an organism possesses a Butters gp57r locus that can protect bacteria from bacteriophage infection. definition_source: DOI:10.1101/2023.01.03.522681 trait_category: GENOMICS term_kind: CLASS mapping_status: PROPOSED parent_traits: - traitmech:000209 synonyms: - synonym_text: Butters_gp57r synonym_type: RELATED_SYNONYM source: https://raw.githubusercontent.com/mdmparis/defense-finder-models/afb0e5a8b466be53586b13266f5d38d98c3ac268/List_system_article.md evidence: - reference: DOI:10.1101/2023.01.03.522681 snippet: Butters gp57r is both necessary and sufficient to inhibit infection by Island3 and other phages notes: Mohammed et al. report Butters gp57r as the Butters component that can block Island3 and additional heterotypic phages. - reference: DOI:10.1101/2023.01.03.522681 snippet: mc2155(gp57r) recapitulated defense against Island3 comparable to that mounted by mc2155(Butters) notes: Mohammed et al. show that expressing Butters gene 57r is sufficient to reproduce Butters-like defense against Island3. - reference: DOI:10.1101/2023.01.03.522681 snippet: Results show that Butters gp57r defends against several other phages (Fig. 3A) notes: Mohammed et al. test the breadth of the cloned gp57r defense and find protection against additional heterotypic phages. - reference: DOI:10.1101/2023.01.03.522681 snippet: the proposal that gp57r acts downstream of DNA injection notes: Mohammed et al. narrow the antiviral effect to a post-DNA-injection step without resolving gp57r's direct molecular substrate. - reference: https://raw.githubusercontent.com/mdmparis/defense-finder-models/afb0e5a8b466be53586b13266f5d38d98c3ac268/List_system_article.md snippet: Butters_gp57r | 10\.1101/2023\.01\.03\.522681 | Identification of a new antiphage system inMycobacteriumphage Butters notes: The DefenseFinder model registry maps the named Butters_gp57r system to the Mohammed et al. Butters gp57r antiphage-system preprint. - reference: https://raw.githubusercontent.com/mdmparis/defense-finder-models/afb0e5a8b466be53586b13266f5d38d98c3ac268/Liste_hmm_system.md snippet: Butters_gp57r__gp57r | Butters_gp57r__gp57r | Butters_gp57r notes: The DefenseFinder HMM inventory records a Butters gp57r profile for Butters_gp57r__gp57r in the Butters_gp57r model namespace. - reference: https://raw.githubusercontent.com/mdmparis/defense-finder-models/afb0e5a8b466be53586b13266f5d38d98c3ac268/DefenseFinder_rules.tsv snippet: "Butters_gp57r\tButters_gp57r\t1\t1\tButters_gp57r__gp57r" notes: The DefenseFinder rules table models Butters_gp57r as a one-component system requiring the gp57r profile. causal_graphs: - graph_id: butters_gp57r_locus_restricts_phage title: Butters gp57r loci confer heterotypic phage defense description: Conservative system-level sketch linking possession of a Butters gp57r locus to restricted bacteriophage propagation without asserting the unresolved gp57r substrate, nuclease output, or phage-tail escape mechanism. scope_status: NONMECHANISTIC scope_notes: The graph captures Butters gp57r as a named anti-phage system with a DefenseFinder gp57r profile while leaving the direct Island3 or PurpleHaze trigger, the role of the HEPN-associated RX4-6H motif, the primary gp57r molecular output, and homolog breadth unresolved. nodes: - node_id: butters_gp57r_locus label: Butters gp57r locus node_type: GENETIC_ELEMENT description: A Butters gp57r anti-phage defense locus cataloged in DefenseFinder with a gp57r HMM profile. - node_id: restricted_phage_propagation label: restricted phage propagation node_type: BIOLOGICAL_PROCESS description: Reduced propagation of bacteriophage in cells carrying the Butters gp57r system. - node_id: butters_gp57r_system_trait label: Butters gp57r system node_type: TRAIT grounding: traitmech:000299 description: Possession of a genome-encoded Butters gp57r 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_gp57r_locus predicate: contributes to predicate_id: RO:0002326 object: restricted_phage_propagation description: Mohammed et al. show that Butters gp57r is necessary and sufficient for Island3 inhibition, and DefenseFinder catalogs a gp57r profile in the Butters_gp57r model namespace. evidence: - reference: DOI:10.1101/2023.01.03.522681 snippet: Butters gp57r is both necessary and sufficient to inhibit infection by Island3 and other phages notes: Mohammed et al. support gp57r as the Butters component that can restrict Island3 and additional heterotypic phages. - reference: https://raw.githubusercontent.com/mdmparis/defense-finder-models/afb0e5a8b466be53586b13266f5d38d98c3ac268/Liste_hmm_system.md snippet: Butters_gp57r__gp57r | Butters_gp57r__gp57r | Butters_gp57r notes: The DefenseFinder HMM inventory records a Butters gp57r profile for Butters_gp57r__gp57r in the Butters_gp57r model namespace. - reference: https://raw.githubusercontent.com/mdmparis/defense-finder-models/afb0e5a8b466be53586b13266f5d38d98c3ac268/DefenseFinder_rules.tsv snippet: "Butters_gp57r\tButters_gp57r\t1\t1\tButters_gp57r__gp57r" notes: The DefenseFinder rules table models Butters_gp57r as a one-component system requiring the gp57r profile. - subject: restricted_phage_propagation predicate: confers predicate_id: METPO:2007700 object: butters_gp57r_system_trait description: Butters-gp57r-associated restriction of phage propagation realizes the Butters gp57r system trait. evidence: - reference: DOI:10.1101/2023.01.03.522681 snippet: mc2155(gp57r) recapitulated defense against Island3 comparable to that mounted by mc2155(Butters) notes: Mohammed et al. show that recombinant expression of Butters gene 57r can reproduce Butters-mediated Island3 defense. - reference: https://raw.githubusercontent.com/mdmparis/defense-finder-models/afb0e5a8b466be53586b13266f5d38d98c3ac268/List_system_article.md snippet: Butters_gp57r | 10\.1101/2023\.01\.03\.522681 | Identification of a new antiphage system inMycobacteriumphage Butters notes: DefenseFinder records Butters_gp57r as a named system from the Mohammed et al. Butters gp57r antiphage-system preprint. - subject: butters_gp57r_system_trait predicate: is a predicate_id: rdfs:subClassOf object: phage_defense_system description: Butters gp57r 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_gp57r | 10\.1101/2023\.01\.03\.522681 | Identification of a new antiphage system inMycobacteriumphage Butters |' notes: DefenseFinder associates Butters_gp57r with the Mohammed et al. Butters gp57r antiphage-system preprint. discussions: - discussion_id: butters_gp57r-mechanism-gap prompt: Resolve the Butters gp57r direct phage trigger, primary molecular target, HEPN-associated RX4-6H motif requirement, DNA-amplification defect, PurpleHaze minor-tail escape route, and homolog breadth before minting narrower Butters gp57r mechanism children. kind: KNOWLEDGE_GAP status: OPEN rationale: Mohammed et al. and DefenseFinder support Butters gp57r as a named anti-phage system with a gp57r profile, but the direct phage trigger, the biochemical role of its predicted HEPN domain and RX4-6H motif, the primary event leading to failed Island3 DNA amplification, and the defense scope of gp57r homologs in other mycobacteriophages or clinical Mycobacterium abscessus isolates are not resolved enough here to assert a narrower mechanistic child trait. attaches_to: - causal_graphs#butters_gp57r_locus_restricts_phage posed_by: codex posed_date: '2026-09-20' curation_history: - timestamp: '2026-09-20T02:22:02Z' curator: codex action: MINTED_TRAITMECH_ID changes: Minted Butters gp57r 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_v176. llm_assisted: true