Avs IV system

traitmech:000537 · CLASS · PROPOSED

An AVAST system in which an organism possesses a genome-encoded subtype IV locus represented by DefenseFinder with an Avs4A profile.

Trait evidence (6)

DOI:10.1126/science.aba0372
AVAST, antiviral ATPase/NTPase of the STAND superfamily

Gao et al. coined AVAST as an antiviral STAND ATPase/NTPase defense-system family.
DOI:10.1126/science.abm4096
Avs1 to Avs3 recognize the large terminase subunit, and Avs4 recognizes the portal

Gao et al. support Avs4 as a phage-portal-sensing member of the AVAST receptor family.
DOI:10.1126/science.abm4096
In all four cases, target recognition led to Avs protein activation and antiviral activity

Gao et al. connect Avs1 through Avs4 target recognition to Avs activation and antiviral activity.
https://raw.githubusercontent.com/mdmparis/defense-finder-models/afb0e5a8b466be53586b13266f5d38d98c3ac268/List_system_article.md
| Avs | 10\.1126/science\.aba0372 | Diverse enzymatic activities mediate antiviral immunity in prokaryotes |

The pinned DefenseFinder article registry maps the Avs source key to the Gao et al. pangenome-scale antiviral-immunity paper.
https://raw.githubusercontent.com/mdmparis/defense-finder-models/afb0e5a8b466be53586b13266f5d38d98c3ac268/Liste_hmm_system.md
| Avs_IV__Avs4A | Avs_IV__Avs4A | Avs_IV | Custom | 60 |

The pinned DefenseFinder HMM inventory records Avs_IV__Avs4A under the Avs_IV model namespace.
https://raw.githubusercontent.com/mdmparis/defense-finder-models/afb0e5a8b466be53586b13266f5d38d98c3ac268/DefenseFinder_rules.tsv
Avs Avs_IV 1 1 Avs_IV__Avs4A

The pinned DefenseFinder rules table models Avs_IV as an Avs subsystem with an Avs4A profile.

Avs IV loci support phage portal recognition

Conservative system-level sketch linking an Avs_IV locus to Avs4-mediated phage portal recognition and Avs IV system possession.

NONMECHANISTIC · The graph captures Avs_IV at locus and Avs4 phage-portal recognition level without asserting the exact Avs4A component role, direct effector activity, native host breadth, sensitive-phage breadth, or whether every DefenseFinder Avs_IV prediction is a complete experimentally active Avs IV locus.

Edge evidence

Avs IV locus contributes to Avs4 phage portal recognition RO:0002326
Avs IV loci encode Avs4 components, and Avs4 belongs to the AVAST receptors that recognize the phage portal protein.
- DOI:10.1126/science.abm4096 Avs1 to Avs3 recognize the large terminase subunit, and Avs4 recognizes the portal Gao et al. support Avs4 as a phage-portal-sensing member of the AVAST receptor family.
- https://raw.githubusercontent.com/mdmparis/defense-finder-models/afb0e5a8b466be53586b13266f5d38d98c3ac268/Liste_hmm_system.md | Avs_IV__Avs4A | Avs_IV__Avs4A | Avs_IV | Custom | 60 | The pinned DefenseFinder HMM inventory records Avs_IV__Avs4A under the Avs_IV model namespace.
Avs4 phage portal recognition confers Avs IV system METPO:2007700
The first-pass Avs IV system trait is realized by Avs4 target recognition and downstream antiviral activity.
- DOI:10.1126/science.abm4096 Avs1 to Avs3 recognize the large terminase subunit, and Avs4 recognizes the portal Gao et al. support Avs4 as a phage-portal-sensing member of the AVAST receptor family.
- DOI:10.1126/science.abm4096 In all four cases, target recognition led to Avs protein activation and antiviral activity Gao et al. connect Avs1 through Avs4 target recognition to Avs activation and antiviral activity.
- https://raw.githubusercontent.com/mdmparis/defense-finder-models/afb0e5a8b466be53586b13266f5d38d98c3ac268/DefenseFinder_rules.tsv Avs Avs_IV 1 1 Avs_IV__Avs4A The pinned DefenseFinder rules table models Avs_IV as an Avs subsystem with an Avs4A profile.
Avs IV system is a AVAST system rdfs:subClassOf
Avs IV system possession is an AVAST-system trait.
- DOI:10.1126/science.aba0372 AVAST, antiviral ATPase/NTPase of the STAND superfamily Gao et al. coined AVAST as an antiviral STAND ATPase/NTPase defense-system family.
- https://raw.githubusercontent.com/mdmparis/defense-finder-models/afb0e5a8b466be53586b13266f5d38d98c3ac268/List_system_article.md | Avs | 10\.1126/science\.aba0372 | Diverse enzymatic activities mediate antiviral immunity in prokaryotes | The pinned DefenseFinder article registry maps the Avs source key to the Gao et al. pangenome-scale antiviral-immunity paper.
- https://raw.githubusercontent.com/mdmparis/defense-finder-models/afb0e5a8b466be53586b13266f5d38d98c3ac268/DefenseFinder_rules.tsv Avs Avs_IV 1 1 Avs_IV__Avs4A The pinned DefenseFinder rules table models Avs_IV as an Avs subsystem with an Avs4A profile.

Provenance

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

Parent traits (1)

AVAST system traitmech:000239

Synonyms (2)

Avs_IV RELATED_SYNONYM · https://raw.githubusercontent.com/mdmparis/defense-finder-models/afb0e5a8b466be53586b13266f5d38d98c3ac268/DefenseFinder_rules.tsv
Avs_IV__Avs4A 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 Avs4A component role, direct effector chemistry, exact phage-trigger mapping, native host breadth, and sensitive-phage breadth before minting Avs IV mechanism or component children.

KNOWLEDGE GAP OPEN avs-iv-component-and-effector-gap · raised by codex · 2026-10-02

Attached to causal_graphs#avs_iv_locus_phage_portal_recognition

Gao et al. support Avs4 phage-portal recognition and Avs activation during antiviral defense, and the pinned DefenseFinder HMM inventory and rules table support Avs_IV as a subtype IV model with an Avs4A profile. This first-pass record leaves the exact component role, downstream effector chemistry, native host breadth, sensitive-phage breadth, and profile-to-activity requirements unresolved.

Evidence

DOI:10.1126/science.abm4096
Avs1 to Avs3 recognize the large terminase subunit, and Avs4 recognizes the portal
DOI:10.1126/science.abm4096
In all four cases, target recognition led to Avs protein activation and antiviral activity
https://raw.githubusercontent.com/mdmparis/defense-finder-models/afb0e5a8b466be53586b13266f5d38d98c3ac268/Liste_hmm_system.md
| Avs_IV__Avs4A | Avs_IV__Avs4A | Avs_IV | Custom | 60 |
https://raw.githubusercontent.com/mdmparis/defense-finder-models/afb0e5a8b466be53586b13266f5d38d98c3ac268/DefenseFinder_rules.tsv
Avs Avs_IV 1 1 Avs_IV__Avs4A

Curation history

2026-10-02T06:35:42Z · MINTED_TRAITMECH_ID · codex
Minted Avs IV system as a DOI- and DefenseFinder-backed GENOMICS TraitRecord under the AVAST 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_v414.
2026-10-02T06:35:43Z · REVIEW_CANONICAL_EXAMPLE_EVIDENCE_GAP · codex
Reviewed Avs IV system during initial curation and left canonical_examples empty because Gao et al. and the pinned DefenseFinder tables support the Avs_IV model namespace and Avs4 phage-portal-recognition activity but not an accession-backed native microbial taxon exemplar with experimentally verified endogenous Avs IV activity. No paid research was used.