SNIPE

A membrane-bound nuclease that cuts phage DNA during injection

AI Gene Review · projects/SNIPE · 2026

Bottom line

  • SNIPE cuts phage DNA as it crosses the inner membrane, using the phage tape measure protein to aim its GIY-YIG nuclease (Saxton et al. 2026, PMID:41741653).
  • The E. coli protein (A0A8T9CRB7) had no GO annotations; our review proposes 7 annotations and 2 new process terms.
  • GO has no place for it: anti-phage nucleic-acid defence is framed as clearing intracellular DNA. A GO issue is drafted; the review is still DRAFT.

The mechanism

Why it matters

  • A third way to tell self from non-self: location, not sequence (CRISPR) or modification (R-M).
  • Homologues in ~33% of well-sequenced bacterial clades; IPR025280 (ex-DUF4041) has 1,612 protein matches.
  • Direct defence: the infected cell survives, unlike abortive infection.
  • InterPro2GO risk: IPR047296 UvrC/Cho-like GIY-YIG → GO:0006289 nucleotide-excision repair would mislabel SNIPE homologues.

What the review proposes

Aspect Term (all NEW, IDA, PMID:41741653)
MF GO:0004520 DNA endonuclease activity · GO:0003690 dsDNA binding
BP GO:0051607 defense response to virus · GO:0045071 neg. reg. of viral genome replication
BP GO:0046597 host-mediated suppression of symbiont invasion · GO:0006308 DNA catabolic process
CC GO:0005887 integral component of plasma membrane

GOA held no rows for A0A8T9CRB7, so every annotation is proposed.

GO cannot place it yet

Two new terms, as rendered

Status and next steps

  • ✅ Paper summarized; full gene review (genes/ECOLX/SNIPE/, DRAFT) with bioinformatics.
  • ✅ GO issue drafted: projects/SNIPE/go-issue-antiviral-nucleic-acid-defense.md (no filed number recorded).
  • ⬜ Check GO annotations on SNIPE homologues; cross-reference DefenseFinder.
  • ⬜ Propose InterPro2GO for PF13250 / IPR025280; flag the IPR047296 → GO:0006289 risk.

Read more: projects/SNIPE.md · genes/ECOLX/SNIPE/SNIPE-ai-review.yaml