Bactaegion does not duplicate any scientific data. Everything comes from public databases.
The system that holds the line against almost every phage.
Système à 2 composants (HamA hélicase + HamB nucléase) qui détecte l'infection et dégrade l'ADN phagique. Présent dans ~3 % des génomes bactériens. Mécanisme bien caractérisé, mais sans cible humaine directe identifiée.
Hachiman was a Japanese Shinto god of war and protector of samurai — a figure of broad-spectrum defense. The anti-phage system that bears his name earns the comparison: it defends against an exceptional diversity of phages across multiple taxonomic families. Its architecture is minimalist — just two proteins, HamA (a helicase ATPase) and HamB (a nuclease) — but this simplicity hides a fascinating question: what does HamA recognize that is conserved across so many different phages? Probably a universal motif of the phage replication cycle, perhaps a replication intermediate or a secondary DNA structure specific to the lytic phase.
Hachiman's "surveillance ATPase + conditional effector" architecture has a direct parallel with human RIG-I / MDA5 (helicase sensors of viral RNA that activate type I interferon). Understanding how HamA recognizes a conserved phage motif would illuminate the design of RIG-I/MDA5 modulators to potentiate innate antiviral immunity.
The Bernheim 2026 atlas (Pasteur) notes that Hachiman is one of the most understudied anti-phage systems relative to its importance. Present in ~3% of bacterial genomes, but with a tiny published footprint. Open playing field for characterizing a mechanism that works against almost everything.
No open lead yet. Frame the first one.
