identifier: traitmech:000301 label: BstA system definition: An abortive infection system in which an organism possesses a BstA-family phage-defense locus whose encoded BstA protein can suppress lytic phage DNA replication and whose cognate anti-BstA aba element can self-immunize the encoding prophage from BstA activity. definition_source: DOI:10.1016/j.chom.2021.09.002 trait_category: GENOMICS term_kind: CLASS mapping_status: PROPOSED parent_traits: - traitmech:000214 synonyms: - synonym_text: BstA synonym_type: RELATED_SYNONYM source: https://raw.githubusercontent.com/mdmparis/defense-finder-models/afb0e5a8b466be53586b13266f5d38d98c3ac268/List_system_article.md evidence: - reference: DOI:10.1016/j.chom.2021.09.002 snippet: we identify BstA, a family of prophage-encoded phage-defense proteins in diverse Gram-negative bacteria notes: Owen et al. name BstA as a family of prophage-encoded phage-defense proteins. - reference: DOI:10.1016/j.chom.2021.09.002 snippet: the BstA protein confers effective population-level defense against exogenous phage infection via abortive infection notes: Owen et al. support BstA as an abortive-infection phage-defense system. - reference: DOI:10.1016/j.chom.2021.09.002 snippet: demonstrating that the BstA protein mediates defense against phage P22 notes: Owen et al. show that phage resistance against P22 is BstA-protein dependent. - reference: DOI:10.1016/j.chom.2021.09.002 snippet: BstA provides phage defense at the population level and prevents the spread of phage epidemics notes: Owen et al. connect BstA activity to suppression of phage epidemics at population level. - reference: DOI:10.1016/j.chom.2021.09.002 snippet: phage DNA replication is strongly suppressed by BstA, but replication can be rescued by the aba element notes: Owen et al. support the direct phage-DNA-replication output of BstA and suppression by the cognate aba self-immunity element. - reference: DOI:10.1016/j.chom.2021.09.002 snippet: each bstA locus contains a cognate aba element that is inactive against variant BstA proteins notes: Owen et al. show that aba self-immunity is cognate to its co-encoded BstA variant. - reference: https://raw.githubusercontent.com/mdmparis/defense-finder-models/afb0e5a8b466be53586b13266f5d38d98c3ac268/List_system_article.md snippet: BstA | 10\.1101/2020\.07\.13\.199331 | Prophage-encoded phage defense proteins with cognate self-immunity notes: The DefenseFinder article registry maps the named BstA system to the Owen et al. BstA preprint. - reference: https://raw.githubusercontent.com/mdmparis/defense-finder-models/afb0e5a8b466be53586b13266f5d38d98c3ac268/Liste_hmm_system.md snippet: BstA__BstA | BstA__BstA | BstA notes: The DefenseFinder HMM inventory records a BstA profile for BstA__BstA in the BstA model namespace. - reference: https://raw.githubusercontent.com/mdmparis/defense-finder-models/afb0e5a8b466be53586b13266f5d38d98c3ac268/DefenseFinder_rules.tsv snippet: "BstA\tBstA\t1\t1\tBstA__BstA" notes: The DefenseFinder rules table models BstA as a one-component system requiring the BstA__BstA profile. canonical_examples: - taxon_id: NCBITaxon:568708 taxon_label: Salmonella enterica subsp. enterica serovar Typhimurium str. D23580 note: Owen et al. studied BstA in the BTP1 prophage of Salmonella enterica serovar Typhimurium ST313 strain D23580 and showed that BstA mediates defense against Salmonella phage P22. reference: DOI:10.1016/j.chom.2021.09.002 causal_graphs: - graph_id: bsta_locus_suppresses_phage_dna_replication title: BstA loci suppress lytic phage DNA replication through abortive infection description: Conservative system-level sketch linking possession of a BstA phage-defense locus to suppressed lytic phage DNA replication, cognate aba-mediated self-immunity, and the BstA system trait without asserting the unresolved direct phage trigger, BstA molecular target, or mechanism of aba-mediated self-immunity. scope_status: NONMECHANISTIC scope_notes: The graph captures BstA as a named abortive-infection system with a DefenseFinder BstA profile while leaving the direct trigger of BstA localization, the direct DNA replication target, the physical form of the BstA-aba interaction, and the molecular basis for cognate aba specificity unresolved. nodes: - node_id: bsta_locus label: BstA locus node_type: GENETIC_ELEMENT description: A BstA-family phage-defense locus carrying a BstA coding sequence. - node_id: aba_element label: aba self-immunity element node_type: GENETIC_ELEMENT description: A cognate anti-BstA aba element carried alongside BstA in a BstA-encoding prophage. - node_id: suppressed_encoding_prophage_dna_replication label: suppressed encoding-prophage DNA replication node_type: BIOLOGICAL_PROCESS description: BstA-mediated suppression of DNA replication by the BstA-encoding prophage in an aba-sensitive context. - node_id: suppressed_lytic_phage_dna_replication label: suppressed lytic phage DNA replication node_type: BIOLOGICAL_PROCESS description: Strong suppression of infecting lytic-phage DNA replication by BstA activity. - node_id: bsta_system_trait label: BstA system node_type: TRAIT grounding: traitmech:000301 description: Possession of a genome-encoded BstA abortive-infection phage-defense system. - node_id: abortive_infection_system label: abortive infection system node_type: TRAIT grounding: traitmech:000214 description: Possession of a bacteriophage abortive-infection defense system. edges: - subject: bsta_locus predicate: includes predicate_id: biolink:has_part object: aba_element description: BstA loci contain a cognate anti-BstA aba self-immunity element. evidence: - reference: DOI:10.1016/j.chom.2021.09.002 snippet: each bstA locus contains a cognate aba element that is inactive against variant BstA proteins notes: Owen et al. show that BstA loci carry cognate aba elements. - subject: bsta_locus predicate: contributes to predicate_id: RO:0002326 object: suppressed_lytic_phage_dna_replication description: Owen et al. show that BstA can strongly suppress lytic phage DNA replication, and DefenseFinder catalogs a one-component BstA model. evidence: - reference: DOI:10.1016/j.chom.2021.09.002 snippet: phage DNA replication is strongly suppressed by BstA notes: Owen et al. link BstA to strong suppression of phage DNA replication. - reference: https://raw.githubusercontent.com/mdmparis/defense-finder-models/afb0e5a8b466be53586b13266f5d38d98c3ac268/Liste_hmm_system.md snippet: BstA__BstA | BstA__BstA | BstA notes: The DefenseFinder HMM inventory records a BstA profile for BstA__BstA in the BstA model namespace. - reference: https://raw.githubusercontent.com/mdmparis/defense-finder-models/afb0e5a8b466be53586b13266f5d38d98c3ac268/DefenseFinder_rules.tsv snippet: "BstA\tBstA\t1\t1\tBstA__BstA" notes: The DefenseFinder rules table models BstA as a one-component system requiring the BstA__BstA profile. - subject: bsta_locus predicate: contributes to predicate_id: RO:0002326 object: suppressed_encoding_prophage_dna_replication description: BstA can suppress DNA replication by an aba-sensitive encoding prophage before cognate aba self-immunity rescues replication. evidence: - reference: DOI:10.1016/j.chom.2021.09.002 snippet: phage DNA replication is strongly suppressed by BstA, but replication can be rescued by the aba element notes: Owen et al. show that BstA supplies the suppression that the cognate aba element counteracts. - subject: aba_element predicate: prevents predicate_id: RO:0002212 object: suppressed_encoding_prophage_dna_replication description: Owen et al. show that the cognate anti-BstA aba element rescues its encoding prophage's DNA replication from BstA-mediated suppression. evidence: - reference: DOI:10.1016/j.chom.2021.09.002 snippet: phage DNA replication is strongly suppressed by BstA, but replication can be rescued by the aba element notes: Owen et al. show that aba counteracts BstA-mediated suppression of phage DNA replication. - reference: DOI:10.1016/j.chom.2021.09.002 snippet: each bstA locus contains a cognate aba element that is inactive against variant BstA proteins notes: Owen et al. show that aba self-immunity is specific to its cognate co-encoded BstA variant. - subject: suppressed_lytic_phage_dna_replication predicate: confers predicate_id: METPO:2007700 object: bsta_system_trait description: BstA-mediated suppression of lytic-phage DNA replication realizes BstA-system abortive-infection defense. evidence: - reference: DOI:10.1016/j.chom.2021.09.002 snippet: We propose that BstA protein mediates abortive infection by suppressing phage DNA replication notes: Owen et al. propose phage-DNA-replication suppression as the mechanism by which BstA mediates abortive infection. - reference: https://raw.githubusercontent.com/mdmparis/defense-finder-models/afb0e5a8b466be53586b13266f5d38d98c3ac268/List_system_article.md snippet: BstA | 10\.1101/2020\.07\.13\.199331 | Prophage-encoded phage defense proteins with cognate self-immunity notes: The DefenseFinder article registry maps the named BstA system to the Owen et al. BstA preprint. - subject: bsta_system_trait predicate: is a predicate_id: rdfs:subClassOf object: abortive_infection_system description: BstA system possession is an abortive-infection system trait. evidence: - reference: DOI:10.1016/j.chom.2021.09.002 snippet: we propose that BstA is an abortive infection system notes: Owen et al. classify BstA as an abortive-infection system. discussions: - discussion_id: bsta-mechanism-gap prompt: Resolve the direct phage trigger of BstA localization, the direct DNA-replication target, the physical BstA-aba interaction, and the basis of cognate aba specificity before minting narrower BstA-aba mechanism children. kind: KNOWLEDGE_GAP status: OPEN rationale: Owen et al. and DefenseFinder support BstA as a named abortive-infection system with a BstA HMM profile and a cognate aba self-immunity element, but the direct phage trigger that recruits BstA to phage DNA, the precise target by which BstA suppresses lytic phage DNA replication, the physical interaction between aba DNA and BstA, and the molecular basis of BstA-aba specificity remain unresolved. attaches_to: - causal_graphs#bsta_locus_suppresses_phage_dna_replication posed_by: codex posed_date: '2026-09-20' curation_history: - timestamp: '2026-09-20T04:37:48Z' curator: codex action: MINTED_TRAITMECH_ID changes: Minted BstA system as a DOI-backed GENOMICS TraitRecord under the abortive infection system parent 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_v178. llm_assisted: true - timestamp: '2026-09-20T05:13:00Z' curator: codex action: ADDRESS_PR_REVIEW changes: Added a Salmonella enterica serovar Typhimurium D23580 canonical example and represented the anti-BstA aba element as an explicit graph node with a supported rescue edge after the PR 1111 adversarial review filed issues 1112 and 1113. llm_assisted: true - timestamp: '2026-09-20T05:25:30Z' curator: codex action: ADDRESS_PR_REVIEW changes: Separated aba self-immunity for the BstA-encoding prophage from BstA-mediated suppression of incoming lytic phage DNA replication after the PR 1111 adversarial review filed issue 1114. llm_assisted: true - timestamp: '2026-09-20T05:42:00Z' curator: codex action: ADDRESS_PR_REVIEW changes: Added an explicit BstA locus contribution edge to the aba-sensitive encoding-prophage DNA replication suppression node after the PR 1111 adversarial review filed issue 1116. llm_assisted: true