Lit system

traitmech:000363 · CLASS · PROPOSED

A phage defense system in which an organism possesses a Lit locus represented by DefenseFinder as a single-profile model requiring Lit__Lit.

Trait evidence (5)

PMID:15196039
Bacteriophage exclusion is a suicide response to viral infection. In strains of Escherichia coli K-12 infected with T4 phage this process is mediated by the host-encoded Lit peptidase. Lit is activated by a unique sequence in the major head protein of the T4 phage (the Gol sequence) which then cleaves site-specifically the host translation factor EF-Tu, ultimately leading to cell death.

Copeland et al. support host Lit as a T4-activated bacteriophage-exclusion peptidase that cleaves EF-Tu and leads to cell death.
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 Gol-Lit as a T4 phage-exclusion system whose output is cofactor-assisted activation of EF-Tu proteolysis.
https://raw.githubusercontent.com/mdmparis/defense-finder-models/afb0e5a8b466be53586b13266f5d38d98c3ac268/List_system_article.md
Lit | 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 Lit system to the Uzan et al. T4 post-transcriptional-control review.
https://raw.githubusercontent.com/mdmparis/defense-finder-models/afb0e5a8b466be53586b13266f5d38d98c3ac268/DefenseFinder_rules.tsv
Lit Lit 1 1 Lit__Lit

The DefenseFinder rules table models Lit as a single-mandatory-profile system with the Lit__Lit profile.
https://raw.githubusercontent.com/mdmparis/defense-finder-models/afb0e5a8b466be53586b13266f5d38d98c3ac268/Liste_hmm_system.md
| Lit__Lit | Lit__Lit | Lit | Custom | 20 |

The DefenseFinder HMM inventory records Lit__Lit under Lit.

Lit loci confer T4 phage exclusion

Conservative system-level sketch linking possession of a Lit locus to T4 Gol-Lit phage exclusion without asserting a protein-resolved Lit mechanism node.

NONMECHANISTIC · The graph captures Lit as a named DefenseFinder single-profile phage-exclusion system while leaving natural host breadth, non-e14 Lit loci, and the exact DefenseFinder profile-to-activity mapping unresolved.

Edge evidence

Lit locus contributes to T4 Gol-Lit phage exclusion RO:0002326
Lit phage-defense loci can mediate T4 bacteriophage exclusion through Gol-activated EF-Tu proteolysis, and DefenseFinder models Lit as a single-profile system.
- PMID:15196039 Bacteriophage exclusion is a suicide response to viral infection. In strains of Escherichia coli K-12 infected with T4 phage this process is mediated by the host-encoded Lit peptidase. Lit is activated by a unique sequence in the major head protein of the T4 phage (the Gol sequence) which then cleaves site-specifically the host translation factor EF-Tu, ultimately leading to cell death. Copeland et al. support Lit-mediated bacteriophage exclusion and EF-Tu cleavage.
- 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 Gol-Lit as a phage-exclusion system mediated by EF-Tu proteolysis.
- https://raw.githubusercontent.com/mdmparis/defense-finder-models/afb0e5a8b466be53586b13266f5d38d98c3ac268/List_system_article.md Lit | 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 Lit system to the Uzan et al. T4 post-transcriptional-control review.
- https://raw.githubusercontent.com/mdmparis/defense-finder-models/afb0e5a8b466be53586b13266f5d38d98c3ac268/DefenseFinder_rules.tsv Lit Lit 1 1 Lit__Lit The DefenseFinder rules table models Lit as a single-mandatory-profile system with the Lit__Lit profile.
- https://raw.githubusercontent.com/mdmparis/defense-finder-models/afb0e5a8b466be53586b13266f5d38d98c3ac268/Liste_hmm_system.md | Lit__Lit | Lit__Lit | Lit | Custom | 20 | The DefenseFinder HMM inventory records Lit__Lit under Lit.
T4 Gol-Lit phage exclusion confers Lit system METPO:2007700
T4 Gol-Lit phage exclusion realizes the Lit system trait.
- PMID:15196039 Bacteriophage exclusion is a suicide response to viral infection. In strains of Escherichia coli K-12 infected with T4 phage this process is mediated by the host-encoded Lit peptidase. Lit is activated by a unique sequence in the major head protein of the T4 phage (the Gol sequence) which then cleaves site-specifically the host translation factor EF-Tu, ultimately leading to cell death. Copeland et al. connect host-encoded Lit to T4 bacteriophage exclusion.
Lit system is a phage defense system rdfs:subClassOf
Lit system possession is a phage-defense-system trait.
- https://raw.githubusercontent.com/mdmparis/defense-finder-models/afb0e5a8b466be53586b13266f5d38d98c3ac268/List_system_article.md Lit | 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 Lit system to the Uzan et al. T4 post-transcriptional-control review.
- https://raw.githubusercontent.com/mdmparis/defense-finder-models/afb0e5a8b466be53586b13266f5d38d98c3ac268/DefenseFinder_rules.tsv Lit Lit 1 1 Lit__Lit The DefenseFinder rules table models Lit as a single-mandatory-profile system with the Lit__Lit profile.

Provenance

Identifier source: TraitMech local identifier
Definition source: DOI:10.1021/bi0495026

Parent traits (1)

phage defense system traitmech:000209

Synonyms (3)

Lit RELATED_SYNONYM · https://raw.githubusercontent.com/mdmparis/defense-finder-models/afb0e5a8b466be53586b13266f5d38d98c3ac268/List_system_article.md
Gol-Lit RELATED_SYNONYM · PMID:21129205
Lit__Lit 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 Lit loci, host breadth beyond Escherichia coli K-12 e14, Gol-activation contexts, and Lit__Lit profile-to-activity mapping before minting narrower Lit mechanism children.

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

Attached to causal_graphs#lit_locus_restricts_t4_phage

Copeland et al. support the T4-triggered e14 Lit peptidase as a bacteriophage-exclusion determinant, Uzan et al. summarize Gol-Lit as a T4 phage-exclusion system, and DefenseFinder models Lit as a single-profile system. The natural host breadth and profile-to-activity mapping remain unresolved.

Curation history

2026-09-22T10:38:17Z · MINTED_TRAITMECH_ID · codex
Minted Lit 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_v240.