Brc23 system

traitmech:000524 · CLASS · PROPOSED

A phage defense system in which an organism possesses a gcu23/Brc23 bacteriophage-resistance integron cassette that supports growth during bacteriophage challenge.

Trait evidence (6)

DOI:10.1126/science.ads0915
gcu23 had a broader defense profile, including high resistance levels against G4, MS2, F1, and T4

Kieffer et al. report that the former gcu23 cassette conferred a broader phage-defense profile with high G4, MS2, F1, and T4 resistance levels.
DOI:10.1126/science.ads0915
We therefore redefined both cassettes as BRiCs (brc22 and brc23)

Kieffer et al. renamed gcu22 and gcu23 as Brc cassettes after phage-resistance testing.
DOI:10.1126/science.ads0915
Predicted secondary structures of attC sites in identified BRiCs

Kieffer et al. identify BRiC bacteriophage-resistance integron cassettes and show their predicted attC secondary structures.
DOI:10.1126/science.ads0915
brc113 brc217 brc76 brcWGS21 brc22 brc23

Kieffer et al. include brc23 among identified BRiCs with predicted attC secondary structures.
https://www.science.org/doi/suppl/10.1126/science.ads0915/suppl_file/science.ads0915_sm.pdf
D279 pMBA PcW brc23 E. coli IJ1862

Kieffer et al.'s supplementary construct table lists pMBA PcW brc23 in E. coli IJ1862 under naturally occurring defense island constructs.
https://www.science.org/doi/suppl/10.1126/science.ads0915/suppl_file/science.ads0915_sm.pdf
D284 pMBA PcW brc23 K. pneumoniae KP5

Kieffer et al.'s supplementary construct table lists pMBA PcW brc23 in Klebsiella pneumoniae KP5 under naturally occurring defense island constructs.

Brc23 BRiCs confer phage resistance

Conservative system-level sketch linking a gcu23/Brc23 bacteriophage-resistance integron cassette to phage resistance and Brc23 system possession.

NONMECHANISTIC · The graph captures Brc23 at the integron-cassette and phage-resistance-output level without asserting the native host range, exact sensitive-phage breadth outside the reported panels, direct molecular substrate, whether Brc22 and Brc23 are variants of one Tragantia family, or a DefenseFinder article/HMM/rules profile absent from the pinned snapshot.

Edge evidence

Brc23 integron cassette contributes to Brc23 phage resistance RO:0002326
The gcu23/Brc23 integron cassette contributes to G4, MS2, F1, and T4 phage resistance during phage-panel assays.
- DOI:10.1126/science.ads0915 gcu23 had a broader defense profile, including high resistance levels against G4, MS2, F1, and T4 Kieffer et al. report that the former gcu23 cassette conferred a broader phage-defense profile with high G4, MS2, F1, and T4 resistance levels.
Brc23 phage resistance confers Brc23 system METPO:2007700
Brc23-linked phage resistance realizes the Brc23 system possession trait.
- DOI:10.1126/science.ads0915 gcu23 had a broader defense profile, including high resistance levels against G4, MS2, F1, and T4 Kieffer et al. report that the former gcu23 cassette conferred a broader phage-defense profile with high G4, MS2, F1, and T4 resistance levels.
- DOI:10.1126/science.ads0915 We therefore redefined both cassettes as BRiCs (brc22 and brc23) Kieffer et al. renamed gcu22 and gcu23 as Brc cassettes after phage-resistance testing.
Brc23 system is a phage defense system rdfs:subClassOf
Brc23 system possession is a phage-defense-system trait.
- DOI:10.1126/science.ads0915 Predicted secondary structures of attC sites in identified BRiCs Kieffer et al. identify BRiC bacteriophage-resistance integron cassettes and show their predicted attC secondary structures.
- DOI:10.1126/science.ads0915 brc113 brc217 brc76 brcWGS21 brc22 brc23 Kieffer et al. include brc23 among identified BRiCs with predicted attC secondary structures.

Provenance

Identifier source: TraitMech local identifier
Definition source: DOI:10.1126/science.ads0915

Parent traits (1)

phage defense system traitmech:000209

Synonyms (2)

gcu23 RELATED_SYNONYM · DOI:10.1126/science.ads0915
brc23 RELATED_SYNONYM · DOI:10.1126/science.ads0915

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 Brc23 native host breadth, exact sensitive-phage breadth, molecular output, Tragantia-family boundaries, and DefenseFinder article/HMM/rules coverage before minting narrower Brc23 mechanism children.

KNOWLEDGE GAP OPEN brc23-defensefinder-model-gap · raised by codex · 2026-10-01

Attached to causal_graphs#brc23_integron_cassette_confers_phage_resistance

Kieffer et al. identify brc23 as a bacteriophage-resistance integron cassette. The pinned DefenseFinder article registry, HMM inventory, and rules table have no exact gcu23 or Brc23 row, so the first-pass record leaves native-host breadth, profile boundaries, exact phage target breadth, direct molecular output, and Brc22/Brc23 Tragantia-family scope unresolved.

Evidence

DOI:10.1126/science.ads0915
gcu23 had a broader defense profile, including high resistance levels against G4, MS2, F1, and T4
DOI:10.1126/science.ads0915
We therefore redefined both cassettes as BRiCs (brc22 and brc23)
DOI:10.1126/science.ads0915
Predicted secondary structures of attC sites in identified BRiCs
DOI:10.1126/science.ads0915
brc113 brc217 brc76 brcWGS21 brc22 brc23
https://www.science.org/doi/suppl/10.1126/science.ads0915/suppl_file/science.ads0915_sm.pdf
D279 pMBA PcW brc23 E. coli IJ1862
https://www.science.org/doi/suppl/10.1126/science.ads0915/suppl_file/science.ads0915_sm.pdf
D284 pMBA PcW brc23 K. pneumoniae KP5
https://raw.githubusercontent.com/mdmparis/defense-finder-models/afb0e5a8b466be53586b13266f5d38d98c3ac268/List_system_article.md
https://raw.githubusercontent.com/mdmparis/defense-finder-models/afb0e5a8b466be53586b13266f5d38d98c3ac268/Liste_hmm_system.md
https://raw.githubusercontent.com/mdmparis/defense-finder-models/afb0e5a8b466be53586b13266f5d38d98c3ac268/DefenseFinder_rules.tsv

Curation history

2026-10-01T20:08:00Z · MINTED_TRAITMECH_ID · codex
Minted Brc23 system as a DOI-backed GENOMICS TraitRecord under phage defense system after an ignored-and-hidden duplicate review ruled out same-scope live TraitMech, METPO, history, and prior proposal collisions after reviewing exact Brc23/brc23/gcu23 hits; kept the graph at BRiC integron-cassette level because the pinned DefenseFinder article registry, HMM inventory, and rules table have no exact Brc23 row; the replacement placeholder is reserved in proposals/metpo_traitmech_v401.
2026-10-01T20:08:01Z · REVIEW_CANONICAL_EXAMPLE_EVIDENCE_GAP · codex
Reviewed Brc23 system during initial curation and left canonical_examples empty because the sources support heterologous gcu23/Brc23 phage-resistance assays but not a direct named native microbial isolate exemplar with experimentally verified endogenous Brc23 activity. No paid research was used.