DRT8 system

traitmech:000541 · CLASS · PROPOSED

A DRT system in which an organism possesses a genome-encoded DefenseFinder DRT8 subtype locus represented by a mandatory DRT8__DRT8 profile, optionally accompanied by the DRT8__DRT8b accessory profile.

Trait evidence (6)

DOI:10.1126/science.aba0372
We discovered that a family of uncharacterized reverse transcriptases (RTs) are active defense systems

Gao et al. experimentally support defense-associated reverse transcriptases as active antiphage systems.
DOI:10.1126/science.aba0372
We named these genes defense-associated RTs (DRTs)

Gao et al. coined the defense-associated RT naming that underlies the DRT system family.
DOI:10.1126/science.aba0372
In all cases, mutations in the RT active site [(Y/F)xDD to (Y/F)xAA, where x is any amino acid] abolished activity

Gao et al. connect DRT antiphage activity to conserved reverse-transcriptase active-site residues.
https://raw.githubusercontent.com/mdmparis/defense-finder-models/afb0e5a8b466be53586b13266f5d38d98c3ac268/List_system_article.md
| DRT | 10\.1126/science\.aba0372 | Diverse enzymatic activities mediate antiviral immunity in prokaryotes |

The pinned DefenseFinder article registry maps the DRT source key to the Gao et al. prokaryotic antiviral-immunity paper.
https://raw.githubusercontent.com/mdmparis/defense-finder-models/afb0e5a8b466be53586b13266f5d38d98c3ac268/Liste_hmm_system.md
| DRT8__DRT8 | DRT8__DRT8 | DRT8 | Custom | 200 | | DRT8__DRT8a | | DRT8 | Custom | 250 | | DRT8__DRT8b | DRT8__DRT8b | DRT8 | Custom | 50 |

The pinned DefenseFinder HMM inventory records DRT8__DRT8, DRT8__DRT8a, and DRT8__DRT8b under the DRT8 model namespace, with DRT8__DRT8a lacking an emitted HMM name.
https://raw.githubusercontent.com/mdmparis/defense-finder-models/afb0e5a8b466be53586b13266f5d38d98c3ac268/DefenseFinder_rules.tsv
DRT DRT8 1 1 DRT8__DRT8 DRT8__DRT8b

The pinned DefenseFinder rules table models DRT8 as a DRT subsystem requiring DRT8__DRT8 and optionally admitting DRT8__DRT8b as accessory.

DRT8 loci support DRT antiphage defense

Conservative system-level sketch linking a DRT8 locus to reverse-transcriptase-dependent DRT phage defense and DRT8 system possession.

NONMECHANISTIC · The graph captures DRT8 at DefenseFinder subtype-locus level without asserting the direct DRT8 reverse-transcriptase product, phage trigger, native host breadth, sensitive phage breadth, the DRT8__DRT8b accessory role, why the DRT8__DRT8a HMM inventory row has no emitted HMM name or rule membership, or whether every DefenseFinder DRT8 prediction is a complete experimentally active DRT8 locus.

Edge evidence

DRT8 locus contributes to DRT reverse-transcriptase active-site activity RO:0002326
DRT8 loci are represented in DefenseFinder by custom defense-associated reverse transcriptase profiles.
- DOI:10.1126/science.aba0372 We named these genes defense-associated RTs (DRTs) Gao et al. coined the defense-associated RT naming that underlies the DRT system family.
- https://raw.githubusercontent.com/mdmparis/defense-finder-models/afb0e5a8b466be53586b13266f5d38d98c3ac268/Liste_hmm_system.md | DRT8__DRT8 | DRT8__DRT8 | DRT8 | Custom | 200 | | DRT8__DRT8a | | DRT8 | Custom | 250 | | DRT8__DRT8b | DRT8__DRT8b | DRT8 | Custom | 50 | The pinned DefenseFinder HMM inventory records DRT8__DRT8, DRT8__DRT8a, and DRT8__DRT8b under the DRT8 model namespace, with DRT8__DRT8a lacking an emitted HMM name.
DRT reverse-transcriptase active-site activity confers DRT8 system METPO:2007700
The first-pass DRT8 system trait is realized by a DefenseFinder DRT8 subtype locus within the reverse-transcriptase-dependent DRT family.
- DOI:10.1126/science.aba0372 We discovered that a family of uncharacterized reverse transcriptases (RTs) are active defense systems Gao et al. experimentally support defense-associated reverse transcriptases as active antiphage systems.
- DOI:10.1126/science.aba0372 In all cases, mutations in the RT active site [(Y/F)xDD to (Y/F)xAA, where x is any amino acid] abolished activity Gao et al. connect DRT antiphage activity to conserved reverse-transcriptase active-site residues.
- https://raw.githubusercontent.com/mdmparis/defense-finder-models/afb0e5a8b466be53586b13266f5d38d98c3ac268/DefenseFinder_rules.tsv DRT DRT8 1 1 DRT8__DRT8 DRT8__DRT8b The pinned DefenseFinder rules table models DRT8 as a DRT subsystem requiring DRT8__DRT8 and optionally admitting DRT8__DRT8b as accessory.
DRT8 system is a DRT system rdfs:subClassOf
DRT8 system possession is a DRT-system trait.
- https://raw.githubusercontent.com/mdmparis/defense-finder-models/afb0e5a8b466be53586b13266f5d38d98c3ac268/List_system_article.md | DRT | 10\.1126/science\.aba0372 | Diverse enzymatic activities mediate antiviral immunity in prokaryotes | The pinned DefenseFinder article registry maps the DRT source key to the Gao et al. prokaryotic antiviral-immunity paper.
- https://raw.githubusercontent.com/mdmparis/defense-finder-models/afb0e5a8b466be53586b13266f5d38d98c3ac268/DefenseFinder_rules.tsv DRT DRT8 1 1 DRT8__DRT8 DRT8__DRT8b The pinned DefenseFinder rules table models DRT8 as a DRT subsystem requiring DRT8__DRT8 and optionally admitting DRT8__DRT8b as accessory.

Provenance

Identifier source: TraitMech local identifier
Definition source: https://raw.githubusercontent.com/mdmparis/defense-finder-models/afb0e5a8b466be53586b13266f5d38d98c3ac268/DefenseFinder_rules.tsv

Parent traits (1)

DRT system traitmech:000279

Synonyms (3)

DRT8 RELATED_SYNONYM · https://raw.githubusercontent.com/mdmparis/defense-finder-models/afb0e5a8b466be53586b13266f5d38d98c3ac268/DefenseFinder_rules.tsv
DRT8__DRT8 RELATED_SYNONYM · https://raw.githubusercontent.com/mdmparis/defense-finder-models/afb0e5a8b466be53586b13266f5d38d98c3ac268/Liste_hmm_system.md
DRT8__DRT8b 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 the DRT8 reverse-transcriptase product, direct phage trigger, host breadth, DRT8__DRT8b accessory role, and DRT8__DRT8a HMM-row status before minting DRT8 mechanism or component children.

KNOWLEDGE GAP OPEN drt8-profile-activity-gap · raised by codex · 2026-10-02

Attached to causal_graphs#drt8_locus_reverse_transcriptase_defense

Gao et al. support defense-associated reverse transcriptases as a broad antiphage-system family, and the pinned DefenseFinder HMM inventory and rules table support DRT8 as a DRT subsystem with a mandatory DRT8__DRT8 profile and an accessory DRT8__DRT8b profile. This first-pass record leaves the exact DRT8 RT product, phage trigger, host breadth, DRT8__DRT8b accessory role, and DRT8__DRT8a inventory-row status unresolved.

Evidence

DOI:10.1126/science.aba0372
We discovered that a family of uncharacterized reverse transcriptases (RTs) are active defense systems
DOI:10.1126/science.aba0372
In all cases, mutations in the RT active site [(Y/F)xDD to (Y/F)xAA, where x is any amino acid] abolished activity
https://raw.githubusercontent.com/mdmparis/defense-finder-models/afb0e5a8b466be53586b13266f5d38d98c3ac268/Liste_hmm_system.md
| DRT8__DRT8 | DRT8__DRT8 | DRT8 | Custom | 200 | | DRT8__DRT8a | | DRT8 | Custom | 250 | | DRT8__DRT8b | DRT8__DRT8b | DRT8 | Custom | 50 |
https://raw.githubusercontent.com/mdmparis/defense-finder-models/afb0e5a8b466be53586b13266f5d38d98c3ac268/DefenseFinder_rules.tsv
DRT DRT8 1 1 DRT8__DRT8 DRT8__DRT8b

Curation history

2026-10-02T09:37:24Z · MINTED_TRAITMECH_ID · codex
Minted DRT8 system as a DOI- and DefenseFinder-backed GENOMICS TraitRecord under the DRT system parent 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_v418.
2026-10-02T09:37:25Z · REVIEW_CANONICAL_EXAMPLE_EVIDENCE_GAP · codex
Reviewed DRT8 system during initial curation and left canonical_examples empty because Gao et al. and the pinned DefenseFinder tables support the DRT family and the DRT8 model namespace but not an accession-backed native microbial taxon exemplar tied to DRT8__DRT8 or DRT8__DRT8b and experimentally verified endogenous DRT8 activity. No paid research was used.