Charlie gp32 system

traitmech:000295 · CLASS · PROPOSED

A phage defense system in which an organism possesses a Charlie gp32 locus that can protect bacteria from bacteriophage infection.

Trait evidence (5)

DOI:10.1038/nmicrobiol.2016.251
at least five distinct prophage-expressed viral defense systems that interfere with infection

Dedrick et al. place the Cluster N Charlie gp32 system in a cohort of prophage-expressed defenses against lytic and temperate mycobacteriophages.
DOI:10.1038/nmicrobiol.2016.251
The gene responsible is Charlie 32 (and presumably the analogous genes in Xeno and SkinnyPete), and a Charlie lysogen in which 32 is deleted loses defense against Che9c

Dedrick et al. localize a Cluster N prophage-mediated heterotypic defense to Charlie gene 32.
DOI:10.1038/nmicrobiol.2016.251
The Charlie gp32 defense system is notable in that although it has the characteristics of superinfection exclusion systems – being membrane located and preventing DNA injection – it has remarkable specificity for a single phage among those tested

Dedrick et al. explicitly name the Charlie gp32 defense system as an exclusion-like viral-defense system.
https://raw.githubusercontent.com/mdmparis/defense-finder-models/afb0e5a8b466be53586b13266f5d38d98c3ac268/List_system_article.md
Charlie_gp32 | 10\.1038/nmicrobiol\.2016\.251 | Prophage-mediated defence against viral attack and viral counter-defence

The DefenseFinder model registry maps the named Charlie_gp32 system to the Dedrick et al. prophage-mediated viral-defense paper.
https://raw.githubusercontent.com/mdmparis/defense-finder-models/afb0e5a8b466be53586b13266f5d38d98c3ac268/Liste_hmm_system.md
Charlie_gp32__gp32 | Charlie_gp32__gp32 | Charlie_gp32

The DefenseFinder HMM inventory records gp32 in the Charlie_gp32 model namespace.

Charlie gp32 loci confer heterotypic phage exclusion

Conservative system-level sketch linking possession of a Charlie gp32 locus to blocked Che9c DNA injection and restricted bacteriophage propagation.

NONMECHANISTIC · The graph captures Charlie gp32 as a named anti-phage system with a DefenseFinder gp32 profile and a proposed Che9c-exclusion output while leaving the direct gp32 target, the membrane-blocking mechanism, and homolog breadth unresolved.

Edge evidence

Charlie gp32 locus contributes to blocked Che9c DNA injection RO:0002326
Dedrick et al. identify Charlie 32 as the gene responsible for Che9c defense, and DefenseFinder catalogs a gp32 profile in the Charlie_gp32 model namespace.
- DOI:10.1038/nmicrobiol.2016.251 The gene responsible is Charlie 32 (and presumably the analogous genes in Xeno and SkinnyPete), and a Charlie lysogen in which 32 is deleted loses defense against Che9c Dedrick et al. support Charlie gp32 as the genetic determinant of the Che9c-exclusion phenotype.
- https://raw.githubusercontent.com/mdmparis/defense-finder-models/afb0e5a8b466be53586b13266f5d38d98c3ac268/Liste_hmm_system.md Charlie_gp32__gp32 | Charlie_gp32__gp32 | Charlie_gp32 The DefenseFinder HMM inventory records gp32 in the Charlie_gp32 model namespace.
blocked Che9c DNA injection contributes to restricted phage propagation RO:0002326
Charlie-gp32-mediated blockade of Che9c DNA injection reduces productive phage infection.
- DOI:10.1038/nmicrobiol.2016.251 We propose that Charlie gp32 confers heterotypic exclusion, blocking Che9c DNA injection across the membrane Dedrick et al. interpret Charlie gp32 defense as an exclusion-like block to Che9c DNA injection.
restricted phage propagation confers Charlie gp32 system METPO:2007700
Charlie-gp32-mediated Che9c exclusion realizes the Charlie gp32 system trait.
- DOI:10.1038/nmicrobiol.2016.251 Charlie gp32 confers survival to Che9c infection, which also is a temperate phage Dedrick et al. show a cellular survival outcome for Charlie-gp32-mediated Che9c defense.
- https://raw.githubusercontent.com/mdmparis/defense-finder-models/afb0e5a8b466be53586b13266f5d38d98c3ac268/List_system_article.md Charlie_gp32 | 10\.1038/nmicrobiol\.2016\.251 | Prophage-mediated defence against viral attack and viral counter-defence DefenseFinder records Charlie_gp32 as a named system from the Dedrick et al. prophage-defense paper.
Charlie gp32 system is a phage defense system rdfs:subClassOf
Charlie gp32 system possession is a phage-defense-system trait.
- https://raw.githubusercontent.com/mdmparis/defense-finder-models/afb0e5a8b466be53586b13266f5d38d98c3ac268/List_system_article.md | Charlie_gp32 | 10\.1038/nmicrobiol\.2016\.251 | Prophage-mediated defence against viral attack and viral counter-defence | DefenseFinder associates Charlie_gp32 with the Dedrick et al. prophage-mediated viral-defense paper.

Provenance

Identifier source: TraitMech local identifier
Definition source: DOI:10.1038/nmicrobiol.2016.251

Parent traits (1)

phage defense system traitmech:000209

Synonyms (2)

Charlie gp32 defense system EXACT_SYNONYM · DOI:10.1038/nmicrobiol.2016.251
Charlie_gp32 RELATED_SYNONYM · https://raw.githubusercontent.com/mdmparis/defense-finder-models/afb0e5a8b466be53586b13266f5d38d98c3ac268/List_system_article.md

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 the Charlie gp32 membrane target, Che9c specificity, and homolog breadth before minting narrower Charlie gp32 mechanism children.

KNOWLEDGE GAP OPEN charlie_gp32-mechanism-gap · raised by codex · 2026-09-19

Attached to causal_graphs#charlie_gp32_locus_blocks_phage_entry

Dedrick et al. and DefenseFinder support Charlie gp32 as a named anti-phage system with a gp32 profile, but the direct membrane target, determinants of its Che9c specificity, and breadth of homologous loci are not resolved enough here to assert a narrower mechanistic child trait.

Curation history

2026-09-19T22:40:37Z · MINTED_TRAITMECH_ID · codex
Minted Charlie gp32 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_v172.
2026-09-19T23:02:19Z · CURATION_REVIEW_REVISION · codex
Resolved PR #1089 review issues #1090 and #1091 by dropping the proposed heterotypic-exclusion mechanism from the definition and tightening the Charlie gp32 exact-synonym evidence snippet after rechecking the Dedrick et al. full text and pinned DefenseFinder rows.
2026-09-19T23:11:07Z · CURATION_REVIEW_REVISION · codex
Resolved the follow-up PR #1089 review issue #1091 by restoring a complete Dedrick et al. P25 source clause, including American defense spelling as verified in the local PMC full text.