PrrC system

traitmech:000364 · CLASS · PROPOSED

A phage defense system in which an organism possesses a PrrC locus represented by DefenseFinder as a two-profile model requiring PrrC__EcoprrI and PrrC__PrrC, with type I restriction-modification components accepted as accessory markers.

Trait evidence (8)

PMID:21129205
phage exclusion systems that involve T4-mediated activation of a latent endoribonuclease (PrrC) and cofactor-assisted activation of EF-Tu proteolysis (Gol-Lit)

Uzan et al. name PrrC as a T4-mediated phage-exclusion system that activates a latent endoribonuclease.
PMID:16790566
The tRNA(Lys) anticodon nuclease PrrC is associated in latent form with the type Ic DNA restriction endonuclease EcoprrI and activated by a phage T4-encoded inhibitor of EcoprrI.

Blanga-Kanfi et al. support latent PrrC association with the EcoprrI restriction endonuclease and activation by a T4-encoded EcoprrI inhibitor.
PMID:16790566
This triad exists in all the known PrrC homologs but only some of them feature residues needed for tRNA(Lys) recognition by the Escherichia coli prototype.

Blanga-Kanfi et al. support a family of PrrC homologs whose substrate-recognition residues can differ from the Escherichia coli prototype.
PMID:16790566
The differential conservation and consistent genetic linkage of the PrrC proteins with EcoprrI homologs portray them as a family of restriction RNases of diverse substrate specificities that are mobilized when an associated DNA restriction nuclease is compromised.

Blanga-Kanfi et al. support genetic linkage between PrrC proteins and EcoprrI homologs as a restriction-RNase family mobilized when an associated restriction nuclease is compromised.
https://raw.githubusercontent.com/mdmparis/defense-finder-models/afb0e5a8b466be53586b13266f5d38d98c3ac268/List_system_article.md
PrrC | 10\.1186/1743-422X-7-360 | Post-transcriptional control by bacteriophage T4: mRNA decay and inhibition of translation initiation

The DefenseFinder article registry maps the named PrrC system to the Uzan et al. T4 post-transcriptional-control review.
https://raw.githubusercontent.com/mdmparis/defense-finder-models/afb0e5a8b466be53586b13266f5d38d98c3ac268/DefenseFinder_rules.tsv
PrrC PrrC 2 2 PrrC__EcoprrI, PrrC__PrrC RM__Type_I_REases, RM__Type_I_S

The DefenseFinder rules table models PrrC as a two-profile system requiring the PrrC__EcoprrI and PrrC__PrrC profiles, with type I restriction-modification components as accessory markers.
https://raw.githubusercontent.com/mdmparis/defense-finder-models/afb0e5a8b466be53586b13266f5d38d98c3ac268/Liste_hmm_system.md
| PrrC__EcoprrI | PrrC__EcoprrI | PrrC | Custom | 20 |

The DefenseFinder HMM inventory records PrrC__EcoprrI under PrrC.
https://raw.githubusercontent.com/mdmparis/defense-finder-models/afb0e5a8b466be53586b13266f5d38d98c3ac268/Liste_hmm_system.md
| PrrC__PrrC | PrrC__PrrC | PrrC | Custom | 100 |

The DefenseFinder HMM inventory records PrrC__PrrC under PrrC.

PrrC loci confer T4 phage exclusion

Conservative system-level sketch linking possession of a PrrC locus to T4-induced PrrC restriction-RNase defense without asserting the exact T4 trigger, natural substrate, or accessory component logic.

NONMECHANISTIC · The graph captures PrrC as a named DefenseFinder two-profile phage-exclusion system while leaving natural homolog substrate specificity, the exact EcoprrI accessory composition and profile matching, the phage trigger logic, and PrrC profile-to-activity mapping unresolved.

Edge evidence

PrrC locus contributes to T4-induced PrrC RNase defense RO:0002326
PrrC proteins are genetically linked with EcoprrI homologs and can be mobilized when associated DNA restriction nucleases are compromised, and DefenseFinder models PrrC as a two-profile system.
- PMID:21129205 phage exclusion systems that involve T4-mediated activation of a latent endoribonuclease (PrrC) and cofactor-assisted activation of EF-Tu proteolysis (Gol-Lit) Uzan et al. identify PrrC as a latent endonuclease participating in T4-mediated phage exclusion.
- PMID:16790566 The tRNA(Lys) anticodon nuclease PrrC is associated in latent form with the type Ic DNA restriction endonuclease EcoprrI and activated by a phage T4-encoded inhibitor of EcoprrI. Blanga-Kanfi et al. connect PrrC to EcoprrI and T4 inhibitor-triggered activation.
- PMID:16790566 The differential conservation and consistent genetic linkage of the PrrC proteins with EcoprrI homologs portray them as a family of restriction RNases of diverse substrate specificities that are mobilized when an associated DNA restriction nuclease is compromised. Blanga-Kanfi et al. generalize PrrC homologs as EcoprrI-linked restriction RNases.
- https://raw.githubusercontent.com/mdmparis/defense-finder-models/afb0e5a8b466be53586b13266f5d38d98c3ac268/List_system_article.md PrrC | 10\.1186/1743-422X-7-360 | Post-transcriptional control by bacteriophage T4: mRNA decay and inhibition of translation initiation The DefenseFinder article registry maps the named PrrC system to the Uzan et al. T4 post-transcriptional-control review.
- https://raw.githubusercontent.com/mdmparis/defense-finder-models/afb0e5a8b466be53586b13266f5d38d98c3ac268/DefenseFinder_rules.tsv PrrC PrrC 2 2 PrrC__EcoprrI, PrrC__PrrC RM__Type_I_REases, RM__Type_I_S The DefenseFinder rules table models PrrC as a two-profile system requiring the PrrC__EcoprrI and PrrC__PrrC profiles, with type I restriction-modification components as accessory markers.
- https://raw.githubusercontent.com/mdmparis/defense-finder-models/afb0e5a8b466be53586b13266f5d38d98c3ac268/Liste_hmm_system.md | PrrC__EcoprrI | PrrC__EcoprrI | PrrC | Custom | 20 | The DefenseFinder HMM inventory records PrrC__EcoprrI under PrrC.
- https://raw.githubusercontent.com/mdmparis/defense-finder-models/afb0e5a8b466be53586b13266f5d38d98c3ac268/Liste_hmm_system.md | PrrC__PrrC | PrrC__PrrC | PrrC | Custom | 100 | The DefenseFinder HMM inventory records PrrC__PrrC under PrrC.
T4-induced PrrC RNase defense confers PrrC system METPO:2007700
T4-induced PrrC RNase defense realizes the PrrC system trait.
- PMID:16790566 The tRNA(Lys) anticodon nuclease PrrC is associated in latent form with the type Ic DNA restriction endonuclease EcoprrI and activated by a phage T4-encoded inhibitor of EcoprrI. Blanga-Kanfi et al. support latent PrrC activation by a T4-encoded inhibitor of EcoprrI.
- PMID:16790566 The differential conservation and consistent genetic linkage of the PrrC proteins with EcoprrI homologs portray them as a family of restriction RNases of diverse substrate specificities that are mobilized when an associated DNA restriction nuclease is compromised. Blanga-Kanfi et al. support broader mobilization of EcoprrI-linked PrrC-family restriction RNases.
PrrC system is a phage defense system rdfs:subClassOf
PrrC system possession is a phage-defense-system trait.
- https://raw.githubusercontent.com/mdmparis/defense-finder-models/afb0e5a8b466be53586b13266f5d38d98c3ac268/List_system_article.md PrrC | 10\.1186/1743-422X-7-360 | Post-transcriptional control by bacteriophage T4: mRNA decay and inhibition of translation initiation The DefenseFinder article registry maps the named PrrC system to the Uzan et al. T4 post-transcriptional-control review.
- https://raw.githubusercontent.com/mdmparis/defense-finder-models/afb0e5a8b466be53586b13266f5d38d98c3ac268/DefenseFinder_rules.tsv PrrC PrrC 2 2 PrrC__EcoprrI, PrrC__PrrC RM__Type_I_REases, RM__Type_I_S The DefenseFinder rules table models PrrC as a two-profile system requiring the PrrC__EcoprrI and PrrC__PrrC profiles, with type I restriction-modification components as accessory markers.

Provenance

Identifier source: TraitMech local identifier
Definition source: DOI:10.1186/1743-422X-7-360

Parent traits (1)

phage defense system traitmech:000209

Synonyms (3)

PrrC RELATED_SYNONYM · https://raw.githubusercontent.com/mdmparis/defense-finder-models/afb0e5a8b466be53586b13266f5d38d98c3ac268/List_system_article.md
PrrC__EcoprrI RELATED_SYNONYM · https://raw.githubusercontent.com/mdmparis/defense-finder-models/afb0e5a8b466be53586b13266f5d38d98c3ac268/Liste_hmm_system.md
PrrC__PrrC RELATED_SYNONYM · https://raw.githubusercontent.com/mdmparis/defense-finder-models/afb0e5a8b466be53586b13266f5d38d98c3ac268/Liste_hmm_system.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 natural PrrC homolog substrate specificity, exact EcoprrI accessory composition and profile matching, and phage trigger logic before minting narrower PrrC mechanism children.

KNOWLEDGE GAP OPEN prrc-mechanism-gap · raised by codex · 2026-09-22

Attached to causal_graphs#prrc_locus_restricts_t4_phage

Uzan et al. summarize PrrC as a T4 phage-exclusion system, Blanga-Kanfi et al. support PrrC and EcoprrI homologs as genetically linked restriction RNases, and DefenseFinder models PrrC as a two-profile system with EcoprrI and PrrC markers plus type I restriction-modification accessories. The natural substrates, accessory composition, and phage trigger logic remain unresolved.

Curation history

2026-09-22T11:25:19Z · MINTED_TRAITMECH_ID · codex
Minted PrrC 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_v241.
2026-09-22T11:39:03Z · REVIEW_CANONICAL_EXAMPLE_EVIDENCE_GAP · codex
Reviewed the PrrC canonical_examples gap and left canonical_examples empty: the current evidence supports a named PrrC phage-exclusion system, the pinned DefenseFinder PrrC profiles, and EcoprrI-linked PrrC homologs, but does not cite a directly observed natural microbial taxon with a source-backed PrrC locus. No paid research was used. Fixes #1247.
2026-09-22T11:42:52Z · ADDRESS_PR_REVIEW · codex
Resolved PR #1245 review issue #1249 by removing the bare EcoprrI component name from PrrC system related synonyms while retaining the DefenseFinder PrrC__EcoprrI profile name and Blanga-Kanfi evidence for EcoprrI-linked PrrC homologs.