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Crouga system

traitmech:000500 · CLASS · PROPOSED

A phage defense system in which an organism possesses a Crouga antiviral locus that is encoded by P4-like phage satellites and can protect bacteria from bacteriophage infection.

Trait evidence (4)

  • DOI:10.1093/nar/gkag898
    The Crouga system has some evidence of being an RM-like system, with one of its proteins containing PFAM domains (ResIII, DEAD, and Helicase C) associated with other RM systems

    de Sousa et al. identify Crouga as a named novel P4-associated system with restriction-modification-like domain evidence.

  • DOI:10.1093/nar/gkag898
    We named the novel functional systems according to deities from Lusitanian mythology

    de Sousa et al. introduce Crouga among the named novel functional P4 antiviral systems.

  • DOI:10.1093/nar/gkag898
    Our experimental validation of anti-phage activity for 13 novel systems encoded by P4 confirms that the contribution of defence functions to the pangenomes of P4 and P2, as well as to the antiviral repertoire of their bacterial hosts, will keep surprising us

    de Sousa et al. summarize the validated P4-encoded novel-system cohort in their discussion.

  • https://raw.githubusercontent.com/mdmparis/defense-finder-models/afb0e5a8b466be53586b13266f5d38d98c3ac268/List_system_article.md
    | Crouga | 10\.64898/2026\.02\.27\.708500 | Shuttling, swapping and mixing: the rapid modular evolution of antiviral repertoires in temperate phages and their satellites |

    The pinned DefenseFinder article registry maps the Crouga source key to the de Sousa et al. P4/P2 antiviral-repertoire paper preprint.

Crouga loci confer bacterial phage defense

Conservative system-level sketch linking possession of a Crouga locus to restricted bacteriophage propagation without asserting the unresolved trigger or molecular output.

NONMECHANISTIC · The graph captures Crouga as a named P4 anti-phage system while leaving its source locus, phage trigger, restriction-modification-like molecular roles, antiviral effector output, source-system table rows, and DefenseFinder HMM/rule model coverage unresolved.

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

Edge evidence

  • Crouga locus contributes to restricted phage propagation RO:0002326

    Crouga loci are among the novel P4-encoded systems that can reduce bacteriophage infection.

  • restricted phage propagation confers Crouga system METPO:2007700

    Crouga-mediated phage protection realizes the Crouga system trait.

    • DOI:10.1093/nar/gkag898 Our experimental validation of anti-phage activity for 13 novel systems encoded by P4 confirms that the contribution of defence functions to the pangenomes of P4 and P2, as well as to the antiviral repertoire of their bacterial hosts, will keep surprising us de Sousa et al. connect the named novel P4-system cohort to anti-phage activity.
  • Crouga system is a phage defense system rdfs:subClassOf

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

    • DOI:10.1093/nar/gkag898 Our experimental validation of anti-phage activity for 13 novel systems encoded by P4 confirms that the contribution of defence functions to the pangenomes of P4 and P2, as well as to the antiviral repertoire of their bacterial hosts, will keep surprising us de Sousa et al. frame the named Crouga cohort as newly validated P4-encoded anti-phage defense functions.

Provenance

Identifier source
TraitMech local identifier
Definition source
DOI:10.1093/nar/gkag898

Parent traits (1)

Synonyms (1)

  • Crouga EXACT_SYNONYM · DOI:10.1093/nar/gkag898

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 Crouga locus breadth, exact phage triggers, restriction-modification-like molecular roles, direct antiviral output, source-system table rows, and DefenseFinder HMM/rule coverage before minting narrower Crouga mechanism children.

KNOWLEDGE GAP OPEN crouga-mechanism-and-modelling-gap · raised by codex · 2026-09-30

Attached to causal_graphs#crouga_locus_restricts_phage

de Sousa et al. support Crouga as one of the novel P4-encoded systems with experimental phage-protection activity, and the pinned DefenseFinder article registry maps the Crouga source key to the corresponding preprint. The pinned HMM inventory and rules table have no exact Crouga rows, and this first-pass record does not resolve the tested source locus, complete phage breadth, exact trigger, molecular output, or detection rule.

Evidence

Curation history

  1. · MINTED_TRAITMECH_ID · codex

    Minted Crouga 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_v377.

  2. · REVIEW_CANONICAL_EXAMPLE_EVIDENCE_GAP · codex

    Reviewed Crouga system canonical_examples and left them empty because de Sousa et al. support P4-encoded Crouga phage protection and a DefenseFinder article-registry row, but not a direct named native microbial isolate exemplar with experimentally verified endogenous Crouga activity. No paid research was used.