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Dionysus system

traitmech:000330 · CLASS · PROPOSED

A phage defense system in which an organism possesses a three-gene Dionysus locus encoding DinA, DinB, and DinC components that can block jumbo-phage infection.

Trait evidence (6)

  • DOI:10.1101/2025.09.30.679545
    From over 500 candidate defense systems, we selected nine for experimental testing and validated three: Dionysus, a TerB-encoding system that disrupts early phage infection vesicle formation by Jumbo phages; Ophion, a Radical SAM-containing system that prevents the formation of the Jumbo phage nucleus; and Ambrosia, a tightly regulated RM-like system.

    Keesman et al. named Dionysus among three modular phage-defense candidates validated experimentally from an initial pool of more than 500 candidates.

  • DOI:10.1101/2025.09.30.679545
    Dionysus is named after the god associated with winemaking and the celebration of life. This defense system consists of three genes encoding: DinA, featuring a merozoite adhesive erythrocyte binding protein (MAEBL) and a transmembrane (TM) domain; DinB, a TerB-like protein; and DinC, a pore-forming toxin (PFT) with four TM domains

    Keesman et al. support Dionysus as a three-gene defense system encoding DinA, DinB, and DinC components.

  • DOI:10.1101/2025.09.30.679545
    Both Dionysus and Ophion specifically block infection by jumbo phages, which have evolved specialized compartments to protect their DNA from DNA-targeting host defenses

    Keesman et al. support Dionysus as a system that blocks infection by jumbo phages with early phage infection vesicles.

  • DOI:10.1101/2025.09.30.679545
    Specifically, we show that Dionysus forms pores in the EPI vesicle of the jumbo phage to disrupt the infection cycle of the phage at an early stage, similar to the mechanism described for the Juk phage defense system

    Keesman et al. connect Dionysus to disruption of the jumbo phage early phage infection vesicle and therefore to interruption of the phage infection cycle.

  • DOI:10.1101/2025.09.30.679545
    All three proteins of Dionysus are essential for its protective capacity, as mutating a conserved amino acid within the MAEBL-like domain of DinA (H326A), and deletion of DinB or DinC, resulted in the partial (DinA H326A) or complete loss of anti-phage activity

    Keesman et al. support all three Dionysus proteins as required for full anti-phage protection in the tested system.

  • https://raw.githubusercontent.com/mdmparis/defense-finder-models/afb0e5a8b466be53586b13266f5d38d98c3ac268/List_system_article.md
    Dionysus | 10\.1101/2025\.09\.30\.679545 | Discovery of phage defense systems through component modularity networks

    The DefenseFinder article registry maps the named Dionysus system to the Keesman et al. modular phage-defense discovery preprint; the pinned DefenseFinder HMM inventory and rules table do not list Dionysus, so this row is name-to-paper evidence rather than model-component evidence.

Dionysus loci confer bacterial phage defense

Conservative system-level sketch linking possession of a Dionysus locus to restricted jumbo-phage propagation without asserting the direct phage trigger or protein-resolved pore-forming sequence.

NONMECHANISTIC · The graph captures Dionysus as a named three-gene anti-jumbo-phage system while leaving its direct phage trigger, the DinA/DinB/DinC interaction sequence, the natural locus breadth, and the absence of pinned DefenseFinder HMM or rule rows unresolved.

Dionysus loci confer bacterial phage defense Interactive directed graph showing evidence-backed causal relationships for Dionysus system.

Edge evidence

  • Dionysus locus contributes to restricted phage propagation RO:0002326

    The three-gene Dionysus locus restricts infection by jumbo phages.

    • DOI:10.1101/2025.09.30.679545 Both Dionysus and Ophion specifically block infection by jumbo phages, which have evolved specialized compartments to protect their DNA from DNA-targeting host defenses Keesman et al. report that Dionysus blocks infection by jumbo phages.
    • DOI:10.1101/2025.09.30.679545 All three proteins of Dionysus are essential for its protective capacity, as mutating a conserved amino acid within the MAEBL-like domain of DinA (H326A), and deletion of DinB or DinC, resulted in the partial (DinA H326A) or complete loss of anti-phage activity Keesman et al. report that DinA, DinB, and DinC perturbations reduce or abolish Dionysus anti-phage activity.
  • restricted phage propagation confers Dionysus system METPO:2007700

    Dionysus-mediated phage restriction realizes the Dionysus system trait.

    • DOI:10.1101/2025.09.30.679545 Specifically, we show that Dionysus forms pores in the EPI vesicle of the jumbo phage to disrupt the infection cycle of the phage at an early stage, similar to the mechanism described for the Juk phage defense system Keesman et al. connect Dionysus activity to disruption of the jumbo-phage infection cycle at an early vesicle stage.
    • https://raw.githubusercontent.com/mdmparis/defense-finder-models/afb0e5a8b466be53586b13266f5d38d98c3ac268/List_system_article.md Dionysus | 10\.1101/2025\.09\.30\.679545 | Discovery of phage defense systems through component modularity networks The DefenseFinder article registry maps the named Dionysus system to the Keesman et al. modular phage-defense discovery preprint; the pinned DefenseFinder HMM inventory and rules table do not list Dionysus, so this row is name-to-paper evidence rather than model-component evidence.
  • Dionysus system is a phage defense system rdfs:subClassOf

    Dionysus system possession is a phage-defense-system trait.

    • DOI:10.1101/2025.09.30.679545 From over 500 candidate defense systems, we selected nine for experimental testing and validated three: Dionysus, a TerB-encoding system that disrupts early phage infection vesicle formation by Jumbo phages; Ophion, a Radical SAM-containing system that prevents the formation of the Jumbo phage nucleus; and Ambrosia, a tightly regulated RM-like system. Keesman et al. list Dionysus among experimentally validated phage-defense systems.
    • https://raw.githubusercontent.com/mdmparis/defense-finder-models/afb0e5a8b466be53586b13266f5d38d98c3ac268/List_system_article.md Dionysus | 10\.1101/2025\.09\.30\.679545 | Discovery of phage defense systems through component modularity networks The DefenseFinder article registry maps the named Dionysus system to the Keesman et al. modular phage-defense discovery preprint; the pinned DefenseFinder HMM inventory and rules table do not list Dionysus, so this row is name-to-paper evidence rather than model-component evidence.

Provenance

Identifier source
TraitMech local identifier
Definition source
DOI:10.1101/2025.09.30.679545

Parent traits (1)

Synonyms (1)

  • Dionysus EXACT_SYNONYM · DOI:10.1101/2025.09.30.679545

kg-microbe context

No kg-microbe node embedding matched this record in the 2026-04-25 deepwalk.

Discussions and Knowledge Gaps (1)

Open questions attached to this trait. Seeded by just knowledge-gap-scan and curated; see the corpus-wide index.

Resolve Dionysus phage triggers, EPI-vesicle pore formation, and model coverage before minting narrower Dionysus mechanism children.

KNOWLEDGE GAP OPEN dionysus-jumbo-phage-mechanism-gap · raised by codex · 2026-09-21

Attached to causal_graphs#dionysus_locus_restricts_phage

Keesman et al. support Dionysus as a three-gene anti-jumbo-phage system that disrupts the jumbo-phage EPI vesicle stage, but the direct phage trigger, exact DinA/DinB/DinC interaction sequence, natural locus breadth, and profile-to-component model are not resolved enough here to assert a narrower mechanistic child trait.

Curation history

  1. · MINTED_TRAITMECH_ID · codex

    Minted Dionysus system as a DOI-backed GENOMICS TraitRecord under phage defense system after an ignored-and-hidden duplicate review found no exact live TraitMech, METPO, history, or prior proposal record; the replacement placeholder is reserved in proposals/metpo_traitmech_v207.