identifier: traitmech:000226 label: ToxIN system definition: An abortive infection system in which an organism possesses a toxIN type III protein-RNA toxin-antitoxin locus whose ToxN toxin and tandem ToxI RNA antitoxins constitute a two-component Abi module that inhibits bacterial growth and restricts phage propagation. definition_source: DOI:10.1073/pnas.0808832106 trait_category: GENOMICS term_kind: CLASS mapping_status: PROPOSED parent_traits: - traitmech:000214 evidence: - reference: DOI:10.1073/pnas.0808832106 snippet: A highly effective 2-gene Abi system from the phytopathogen Erwinia carotovora subspecies atroseptica, designated ToxIN, is described notes: Fineran et al. define ToxIN as a two-gene abortive infection system from the native pECA1039 plasmid. - reference: DOI:10.1073/pnas.0808832106 snippet: ToxN inhibiting bacterial growth and the tandemly repeated ToxI RNA antitoxin counteracting the toxicity notes: Fineran et al. connect the ToxN protein toxin and tandem ToxI RNA repeats to the toxin-antitoxin behavior of ToxIN. - reference: DOI:10.1073/pnas.0808832106 snippet: ToxIN defines an entirely new TA class that functions via a novel protein-RNA mechanism notes: Fineran et al. support ToxIN as the defining member of the type III protein-RNA toxin-antitoxin class. - reference: DOI:10.1073/pnas.0808832106 snippet: All of our data are consistent with ToxIN functioning as a phage Abi system notes: Fineran et al. ruled out adsorption blockade and a restriction-modification explanation before classifying ToxIN as abortive infection. - reference: DOI:10.1073/pnas.0808832106 snippet: ToxN functions through a reversible growth-inhibiting (bacteriostatic) mechanism notes: Fineran et al. support host growth inhibition as the ToxN toxin output. - reference: DOI:10.1128/JB.00720-09 snippet: Designated ToxIN, this two-component abortive infection system acts as a toxin-antitoxin module notes: Blower et al. place the two-component ToxIN module in the abortive infection class. - reference: DOI:10.1128/JB.00720-09 snippet: We determined the minimal ToxI RNA sequence in the native operon that is both necessary and sufficient for abortive infection and to counteract the toxicity of ToxN notes: Blower et al. connect ToxI RNA repeat dosage to both ToxN neutralization and the native abortive-infection phenotype. - reference: DOI:10.1128/JB.00720-09 snippet: this two-component Abi system operates as a novel protein-RNA toxin-antitoxin (TA) system to abort phage infection in multiple gram-negative bacteria notes: Blower et al. support the ToxIN system as an Abi trait that can operate beyond the source Erwinia strain. canonical_examples: - taxon_id: NCBITaxon:29471 taxon_label: Pectobacterium atrosepticum note: Fineran et al. isolated pECA1039 from Erwinia carotovora subsp. atroseptica 1039, designated its two-gene Abi system ToxIN, and showed that the native toxIN locus conferred phage resistance in strain SCRI 1043. reference: DOI:10.1073/pnas.0808832106 causal_graphs: - graph_id: toxin_type_iii_ta_antiphage_activity title: ToxIN type III toxin-antitoxin activity restricts phage propagation description: Evidence-backed process sketch linking a toxIN locus to type III toxin-antitoxin activity, ToxN-dependent growth inhibition, restricted phage propagation, and abortive-infection system possession. scope_status: NONMECHANISTIC scope_notes: The graph captures ToxIN at the system level without asserting a universal phage activator, an exact molecular target for ToxN, or the stoichiometry of ToxI neutralization. nodes: - node_id: toxin_locus label: toxIN locus node_type: GENETIC_ELEMENT description: A type III protein-RNA toxin-antitoxin abortive-infection locus encoding the ToxN toxin and tandem ToxI RNA antitoxins. - node_id: toxin_type_iii_toxin_antitoxin_activity label: ToxIN type III toxin-antitoxin activity node_type: BIOLOGICAL_PROCESS description: Protein-RNA toxin-antitoxin activity of ToxIN, in which tandem ToxI RNA repeats counteract ToxN toxicity. - node_id: toxn_growth_inhibition label: ToxN-dependent growth inhibition node_type: BIOLOGICAL_PROCESS description: Reversible bacterial growth inhibition caused by ToxN toxin activity. - node_id: restricted_phage_propagation label: restricted phage propagation node_type: BIOLOGICAL_PROCESS description: Reduced completion of phage propagation in a ToxIN-containing infected host cell. - node_id: toxin_system_trait label: ToxIN system node_type: TRAIT grounding: traitmech:000226 description: Possession of a genome-encoded toxIN type III toxin-antitoxin abortive-infection system. - node_id: abortive_infection_system_trait label: abortive infection system node_type: TRAIT grounding: traitmech:000214 description: Possession of a genome-encoded abortive-infection phage defense system. edges: - subject: toxin_locus predicate: contributes to predicate_id: RO:0002326 object: toxin_type_iii_toxin_antitoxin_activity description: The toxIN locus encodes the defining type III protein-RNA toxin-antitoxin module. evidence: - reference: DOI:10.1073/pnas.0808832106 snippet: ToxIN defines an entirely new TA class that functions via a novel protein-RNA mechanism notes: Fineran et al. show that ToxIN constitutes a protein-RNA toxin-antitoxin system. - subject: toxin_type_iii_toxin_antitoxin_activity predicate: contributes to predicate_id: RO:0002326 object: toxn_growth_inhibition description: The ToxIN toxin-antitoxin module couples ToxN growth inhibition to ToxI RNA antitoxin counteraction. evidence: - reference: DOI:10.1073/pnas.0808832106 snippet: ToxN inhibiting bacterial growth and the tandemly repeated ToxI RNA antitoxin counteracting the toxicity notes: Fineran et al. identify ToxN as the toxic component and ToxI repeats as RNA antitoxins. - subject: toxin_locus predicate: contributes to predicate_id: RO:0002326 object: restricted_phage_propagation description: The native toxIN locus contributes to abortive restriction of phage propagation. evidence: - reference: DOI:10.1073/pnas.0808832106 snippet: All of our data are consistent with ToxIN functioning as a phage Abi system notes: Fineran et al. connect the toxIN locus to the abortive-infection phage resistance output. - subject: restricted_phage_propagation predicate: confers predicate_id: METPO:2007700 object: toxin_system_trait description: Restriction of phage propagation realizes the ToxIN abortive-infection defense trait. evidence: - reference: DOI:10.1128/JB.00720-09 snippet: this two-component Abi system operates as a novel protein-RNA toxin-antitoxin (TA) system to abort phage infection in multiple gram-negative bacteria notes: Blower et al. describe ToxIN as a two-component Abi system that aborts phage infection. - subject: toxin_system_trait predicate: is a predicate_id: rdfs:subClassOf object: abortive_infection_system_trait description: ToxIN system possession is an abortive-infection-system trait. evidence: - reference: DOI:10.1128/JB.00720-09 snippet: Designated ToxIN, this two-component abortive infection system acts as a toxin-antitoxin module notes: Blower et al. place ToxIN in the abortive infection class of phage defense. curation_history: - timestamp: '2026-09-15T19:25:00Z' curator: codex action: MINTED_TRAITMECH_ID changes: Minted ToxIN 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_v103. llm_assisted: true