identifier: traitmech:000276 label: dGTPase system definition: A phage defense system in which an organism possesses a dGTPase locus that degrades dGTP into phosphate-free deoxy-guanosine during phage infection, depletes dGTP from the nucleotide pool, and halts phage replication by starving the phage of an essential DNA building block. definition_source: DOI:10.1101/2021.04.26.441389 trait_category: GENOMICS term_kind: CLASS mapping_status: PROPOSED parent_traits: - traitmech:000209 synonyms: - synonym_text: dGTPase synonym_type: EXACT_SYNONYM source: https://raw.githubusercontent.com/mdmparis/defense-finder-models/afb0e5a8b466be53586b13266f5d38d98c3ac268/List_system_article.md evidence: - reference: DOI:10.1101/2021.04.26.441389 snippet: bacteria employ a similar strategy to defend against phage infection notes: Tal et al. support nucleotide depletion as a bacterial anti-phage strategy. - reference: DOI:10.1101/2021.04.26.441389 snippet: A second family of phage resistance genes encode dGTPase enzymes, which degrade dGTP into phosphate-free deoxy-guanosine (dG) notes: Tal et al. support dGTPase genes as phage-resistance genes encoding enzymes that degrade dGTP. - reference: DOI:10.1101/2021.04.26.441389 snippet: completely eliminate the specific deoxynucleotide (either dCTP or dGTP) from the nucleotide pool during phage infection notes: Tal et al. connect dGTPase defense to dGTP nucleotide-pool elimination during phage infection. - reference: DOI:10.1101/2021.04.26.441389 snippet: starving the phage of an essential DNA building block and halting its replication notes: Tal et al. connect defensive deoxynucleotide depletion to phage DNA-building-block starvation and replication arrest. - reference: https://raw.githubusercontent.com/mdmparis/defense-finder-models/afb0e5a8b466be53586b13266f5d38d98c3ac268/List_system_article.md snippet: dGTPase | 10\.1101/2021\.04\.26\.441389 | Antiviral defense via nucleotide depletion in bacteria notes: The DefenseFinder article registry maps the named dGTPase system to the Tal et al. nucleotide-depletion preprint. - reference: https://raw.githubusercontent.com/mdmparis/defense-finder-models/afb0e5a8b466be53586b13266f5d38d98c3ac268/DefenseFinder_rules.tsv snippet: "dGTPase\tdGTPase\t1\t1\tdGTPase__Sp_dGTPase" notes: The DefenseFinder rules table models dGTPase as a single-profile system. - reference: https://raw.githubusercontent.com/mdmparis/defense-finder-models/afb0e5a8b466be53586b13266f5d38d98c3ac268/Liste_hmm_system.md snippet: dGTPase__Sp_dGTPase | dGTPase__Sp_dGTPase | dGTPase notes: The DefenseFinder HMM inventory records the custom Sp_dGTPase profile. causal_graphs: - graph_id: dgtpase_dgtp_depletion_defense title: dGTPase loci deplete dGTP during phage infection description: Process sketch linking a dGTPase locus to dGTP degradation, dGTP depletion, phage DNA-building-block starvation, halted phage replication, and the dGTPase system trait. scope_status: NONMECHANISTIC scope_notes: The graph captures the DOI abstract's dGTPase-mediated dGTP degradation and nucleotide-depletion output without asserting a universal phage sensor, activation route, strain-resolved enzyme accession, or complete substrate scope for every natural dGTPase system. nodes: - node_id: dgtpase_locus label: dGTPase locus node_type: GENETIC_ELEMENT description: A dGTPase anti-phage defense locus represented by a custom DefenseFinder Sp_dGTPase profile. - node_id: dgtp_degradation label: dGTP degradation into deoxy-guanosine node_type: BIOLOGICAL_PROCESS description: Degradation of dGTP into phosphate-free deoxy-guanosine by defensive dGTPase enzymes. - node_id: dgtp_depletion label: dGTP nucleotide-pool depletion node_type: BIOLOGICAL_PROCESS description: Elimination of dGTP from the nucleotide pool during dGTPase-mediated defense. - node_id: phage_dna_building_block_starvation label: phage DNA-building-block starvation node_type: STATE description: Deprivation of an essential deoxynucleotide needed for phage DNA synthesis. - node_id: halted_phage_replication label: halted phage replication node_type: BIOLOGICAL_PROCESS description: Arrest of bacteriophage replication after dGTP depletion. - node_id: dgtpase_system_trait label: dGTPase system node_type: TRAIT grounding: traitmech:000276 description: Possession of a genome-encoded dGTPase 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: dgtpase_locus predicate: contributes to predicate_id: RO:0002326 object: dgtp_degradation description: The dGTPase locus encodes dGTPase activity that degrades dGTP into phosphate-free deoxy-guanosine. evidence: - reference: DOI:10.1101/2021.04.26.441389 snippet: dGTPase enzymes, which degrade dGTP into phosphate-free deoxy-guanosine (dG) notes: Tal et al. identify dGTPase enzymes that degrade dGTP. - reference: https://raw.githubusercontent.com/mdmparis/defense-finder-models/afb0e5a8b466be53586b13266f5d38d98c3ac268/Liste_hmm_system.md snippet: dGTPase__Sp_dGTPase | dGTPase__Sp_dGTPase | dGTPase notes: DefenseFinder models the Sp_dGTPase protein profile used to identify the dGTPase system. - subject: dgtp_degradation predicate: contributes to predicate_id: RO:0002326 object: dgtp_depletion description: Degradation of dGTP depletes the host dGTP nucleotide pool during phage infection. evidence: - reference: DOI:10.1101/2021.04.26.441389 snippet: completely eliminate the specific deoxynucleotide (either dCTP or dGTP) from the nucleotide pool during phage infection notes: Tal et al. connect defensive dGTPase activity to loss of dGTP from the nucleotide pool. - subject: dgtp_depletion predicate: contributes to predicate_id: RO:0002326 object: phage_dna_building_block_starvation description: dGTP depletion starves the infecting phage of an essential DNA building block. evidence: - reference: DOI:10.1101/2021.04.26.441389 snippet: starving the phage of an essential DNA building block notes: Tal et al. support phage DNA-building-block starvation as the output of defensive deoxynucleotide depletion. - subject: phage_dna_building_block_starvation predicate: contributes to predicate_id: RO:0002326 object: halted_phage_replication description: Starvation for dGTP halts phage DNA replication. evidence: - reference: DOI:10.1101/2021.04.26.441389 snippet: starving the phage of an essential DNA building block and halting its replication notes: Tal et al. place phage-replication arrest downstream of defensive deoxynucleotide depletion. - subject: halted_phage_replication predicate: confers predicate_id: METPO:2007700 object: dgtpase_system_trait description: dGTPase-mediated arrest of phage replication realizes the dGTPase system trait. evidence: - reference: DOI:10.1101/2021.04.26.441389 snippet: bacteria employ a similar strategy to defend against phage infection notes: Tal et al. support dGTP depletion as a bacterial phage-defense strategy. - subject: dgtpase_system_trait predicate: is a predicate_id: rdfs:subClassOf object: phage_defense_system description: dGTPase system possession is a phage-defense-system trait. evidence: - reference: https://raw.githubusercontent.com/mdmparis/defense-finder-models/afb0e5a8b466be53586b13266f5d38d98c3ac268/List_system_article.md snippet: dGTPase | 10\.1101/2021\.04\.26\.441389 | Antiviral defense via nucleotide depletion in bacteria notes: DefenseFinder associates dGTPase with the Tal et al. bacterial antiviral nucleotide-depletion preprint. discussions: - discussion_id: dgtpase-activation-profile-gap prompt: Resolve dGTPase activation, locus boundaries, and representative enzyme accessions before asserting narrower component or subtype traits. kind: KNOWLEDGE_GAP status: OPEN rationale: Tal et al. support dGTPase as a phage-responsive dGTP-depletion defense and DefenseFinder models the system with a custom Sp_dGTPase HMM profile, but this first system-level record does not resolve the universal phage sensor, activation route, strain-level accessions, or whether additional unmodeled components define some natural loci. attaches_to: - causal_graphs#dgtpase_dgtp_depletion_defense posed_by: codex posed_date: '2026-09-19' curation_history: - timestamp: '2026-09-19T10:46:26Z' curator: codex action: MINTED_TRAITMECH_ID changes: Minted dGTPase 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_v153. llm_assisted: true