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 SNIPE-specific process: 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 needs the full architecture: IPR025280, a GIY-YIG co-feature, and membrane-targeting evidence.

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:0005886 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: GO hierarchy NTR (no filed number recorded).
  • ✅ Architecture-aware IPR025280 analysis for conservative InterPro2GO design.
  • ⬜ Check GO annotations on SNIPE homologues; cross-reference DefenseFinder.
  • ⬜ Propose architecture-aware InterPro2GO mappings for PF13250 / IPR025280.

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