identifier: traitmech:000297 label: MMB gp29-gp30 system definition: A phage defense system in which an organism possesses an MMB gp29-gp30 locus that can protect bacteria from bacteriophage infection. definition_source: DOI:10.1038/nmicrobiol.2016.251 trait_category: GENOMICS term_kind: CLASS mapping_status: PROPOSED parent_traits: - traitmech:000209 synonyms: - synonym_text: MMB_gp29_gp30 synonym_type: RELATED_SYNONYM source: https://raw.githubusercontent.com/mdmparis/defense-finder-models/afb0e5a8b466be53586b13266f5d38d98c3ac268/List_system_article.md evidence: - reference: DOI:10.1038/nmicrobiol.2016.251 snippet: at least five distinct prophage-expressed viral defense systems that interfere with infection notes: The PMC author manuscript for Dedrick et al. places the Cluster N MMB gp29-gp30 system in a cohort of prophage-expressed defenses against lytic and temperate mycobacteriophages. - reference: DOI:10.1038/nmicrobiol.2016.251 snippet: Tweety (F1) is targeted by Xerxes, MMB, Phrann and Panchino notes: The PMC author manuscript for Dedrick et al. identifies Tweety as one phage targeted by the MichelleMyBell prophage defense profile. - reference: DOI:10.1038/nmicrobiol.2016.251 snippet: Phages MMB, Xerxes, and Pipsqueaks are closely-related in the lysis-immunity region (Fig. 4a) and MMB and Xerxes have almost identical patterns of defense against eleven individual phages notes: The PMC author manuscript for Dedrick et al. connects the MichelleMyBell and Xerxes defense spectra to their shared lysis-immunity-region context. - reference: DOI:10.1038/nmicrobiol.2016.251 snippet: we constructed a MMB mutant in which genes 29 and 30 are removed (deletions of individual genes appear to generate non-viable mutants; Supplementary Table 3) and showed that prophage-mediated defense is lost notes: The PMC author manuscript for Dedrick et al. deletes the MMB 29-30 interval when testing whether gp29 and gp30 contribute to MMB defense. - reference: DOI:10.1038/nmicrobiol.2016.251 snippet: expressing MMB 29 and 30 confers the same pattern of defense as the MMB lysogen notes: The PMC author manuscript for Dedrick et al. shows that recombinant MMB genes 29 and 30 reproduce the MMB prophage-mediated defense pattern. - reference: DOI:10.1038/nmicrobiol.2016.251 snippet: MMB 29-30 and Phrann 29-30 also confer survival to infection by a lytic Tweety derivative notes: The PMC author manuscript for Dedrick et al. shows that the MMB gp29-gp30 system can protect bacteria from a lytic Tweety derivative in addition to wild-type Tweety. - reference: https://raw.githubusercontent.com/mdmparis/defense-finder-models/afb0e5a8b466be53586b13266f5d38d98c3ac268/List_system_article.md snippet: MMB_gp29_gp30 | 10\.1038/nmicrobiol\.2016\.251 | Prophage-mediated defence against viral attack and viral counter-defence notes: The DefenseFinder model registry maps the named MMB_gp29_gp30 system to the Dedrick et al. prophage-mediated viral-defense paper. - reference: https://raw.githubusercontent.com/mdmparis/defense-finder-models/afb0e5a8b466be53586b13266f5d38d98c3ac268/Liste_hmm_system.md snippet: MMB_gp29_gp30__gp29 | MMB_gp29_gp30__gp29 | MMB_gp29_gp30 notes: The DefenseFinder HMM inventory records an MMB gp29-gp30 profile for MMB_gp29_gp30__gp29 in the MMB_gp29_gp30 model namespace. - reference: https://raw.githubusercontent.com/mdmparis/defense-finder-models/afb0e5a8b466be53586b13266f5d38d98c3ac268/Liste_hmm_system.md snippet: MMB_gp29_gp30__gp30 | MMB_gp29_gp30__gp30 | MMB_gp29_gp30 notes: The DefenseFinder HMM inventory records an MMB gp29-gp30 profile for MMB_gp29_gp30__gp30 in the MMB_gp29_gp30 model namespace. - reference: https://raw.githubusercontent.com/mdmparis/defense-finder-models/afb0e5a8b466be53586b13266f5d38d98c3ac268/DefenseFinder_rules.tsv snippet: "MMB_gp29_gp30\tMMB_gp29_gp30\t2\t2\tMMB_gp29_gp30__gp29, MMB_gp29_gp30__gp30" notes: The DefenseFinder rules table models MMB_gp29_gp30 as a two-component system requiring gp29 and gp30 profiles. causal_graphs: - graph_id: mmb_gp29_gp30_locus_restricts_phage title: MMB gp29-gp30 loci confer heterotypic phage defense description: Conservative system-level sketch linking possession of an MMB gp29-gp30 locus to restricted bacteriophage propagation without asserting the unresolved lytic trigger, gp29-gp30 interaction, or downstream arrest mechanism. scope_status: NONMECHANISTIC scope_notes: The graph captures MMB gp29-gp30 as a named anti-phage system with DefenseFinder gp29 and gp30 profiles while leaving the direct lytic trigger, MMB gp30 regulatory role, MMB gp29 biochemical activity, and exact downstream arrest mechanism unresolved. nodes: - node_id: mmb_gp29_gp30_locus label: MMB gp29-gp30 locus node_type: GENETIC_ELEMENT description: An MMB gp29-gp30 anti-phage defense locus cataloged in DefenseFinder with gp29 and gp30 HMM profiles. - node_id: restricted_phage_propagation label: restricted phage propagation node_type: BIOLOGICAL_PROCESS description: Reduced propagation of bacteriophage in cells carrying the MMB gp29-gp30 system. - node_id: mmb_gp29_gp30_system_trait label: MMB gp29-gp30 system node_type: TRAIT grounding: traitmech:000297 description: Possession of a genome-encoded MMB gp29-gp30 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: mmb_gp29_gp30_locus predicate: contributes to predicate_id: RO:0002326 object: restricted_phage_propagation description: Dedrick et al. show that MMB genes 29 and 30 are necessary and sufficient for the tested MMB defense profile, and DefenseFinder catalogs gp29 and gp30 profiles in the MMB_gp29_gp30 model namespace. evidence: - reference: DOI:10.1038/nmicrobiol.2016.251 snippet: we constructed a MMB mutant in which genes 29 and 30 are removed (deletions of individual genes appear to generate non-viable mutants; Supplementary Table 3) and showed that prophage-mediated defense is lost notes: The PMC author manuscript for Dedrick et al. shows that deleting the MMB 29-30 interval abolishes MMB prophage-mediated defense. - reference: DOI:10.1038/nmicrobiol.2016.251 snippet: expressing MMB 29 and 30 confers the same pattern of defense as the MMB lysogen notes: The PMC author manuscript for Dedrick et al. shows that MMB genes 29 and 30 are sufficient to reproduce the MMB defense pattern. - reference: https://raw.githubusercontent.com/mdmparis/defense-finder-models/afb0e5a8b466be53586b13266f5d38d98c3ac268/Liste_hmm_system.md snippet: MMB_gp29_gp30__gp29 | MMB_gp29_gp30__gp29 | MMB_gp29_gp30 notes: The DefenseFinder HMM inventory records an MMB gp29-gp30 profile for MMB_gp29_gp30__gp29 in the MMB_gp29_gp30 model namespace. - reference: https://raw.githubusercontent.com/mdmparis/defense-finder-models/afb0e5a8b466be53586b13266f5d38d98c3ac268/Liste_hmm_system.md snippet: MMB_gp29_gp30__gp30 | MMB_gp29_gp30__gp30 | MMB_gp29_gp30 notes: The DefenseFinder HMM inventory records an MMB gp29-gp30 profile for MMB_gp29_gp30__gp30 in the MMB_gp29_gp30 model namespace. - reference: https://raw.githubusercontent.com/mdmparis/defense-finder-models/afb0e5a8b466be53586b13266f5d38d98c3ac268/DefenseFinder_rules.tsv snippet: "MMB_gp29_gp30\tMMB_gp29_gp30\t2\t2\tMMB_gp29_gp30__gp29, MMB_gp29_gp30__gp30" notes: The DefenseFinder rules table models MMB_gp29_gp30 as a two-component system requiring gp29 and gp30 profiles. - subject: restricted_phage_propagation predicate: confers predicate_id: METPO:2007700 object: mmb_gp29_gp30_system_trait description: MMB-gp29-gp30-mediated restriction of phage propagation realizes the MMB gp29-gp30 system trait. evidence: - reference: DOI:10.1038/nmicrobiol.2016.251 snippet: expressing MMB 29 and 30 confers the same pattern of defense as the MMB lysogen notes: The PMC author manuscript for Dedrick et al. shows that MMB genes 29 and 30 reproduce the MMB defense pattern. - reference: https://raw.githubusercontent.com/mdmparis/defense-finder-models/afb0e5a8b466be53586b13266f5d38d98c3ac268/List_system_article.md snippet: MMB_gp29_gp30 | 10\.1038/nmicrobiol\.2016\.251 | Prophage-mediated defence against viral attack and viral counter-defence notes: DefenseFinder records MMB_gp29_gp30 as a named system from the Dedrick et al. prophage-defense paper. - subject: mmb_gp29_gp30_system_trait predicate: is a predicate_id: rdfs:subClassOf object: phage_defense_system description: MMB gp29-gp30 system possession is a phage-defense-system trait. evidence: - reference: https://raw.githubusercontent.com/mdmparis/defense-finder-models/afb0e5a8b466be53586b13266f5d38d98c3ac268/List_system_article.md snippet: '| MMB_gp29_gp30 | 10\.1038/nmicrobiol\.2016\.251 | Prophage-mediated defence against viral attack and viral counter-defence |' notes: DefenseFinder associates MMB_gp29_gp30 with the Dedrick et al. prophage-mediated viral-defense paper. discussions: - discussion_id: mmb_gp29_gp30-mechanism-gap prompt: Resolve the MMB gp29 biochemical activity, MMB gp30 regulatory role, lytic trigger, gp29-gp30 interaction, counter-defense specificity, and homolog breadth before minting narrower MMB gp29-gp30 mechanism children. kind: KNOWLEDGE_GAP status: OPEN rationale: Dedrick et al. and DefenseFinder support MMB gp29-gp30 as a named anti-phage system with gp29 and gp30 profiles, but the MMB gp29 biochemical activity, direct gp29-gp30 interaction, triggering Tweety early lytic gene or genes, MMB-specific counter-defense tuning, and relationship to Squirty homologs are not resolved enough here to assert a narrower mechanistic child trait. attaches_to: - causal_graphs#mmb_gp29_gp30_locus_restricts_phage posed_by: codex posed_date: '2026-09-20' curation_history: - timestamp: '2026-09-20T00:13:48Z' curator: codex action: MINTED_TRAITMECH_ID changes: Minted MMB gp29-gp30 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_v174. llm_assisted: true