Scientists uncover bizarre bacterial self-destruct switch

Researchers at Gladstone Institutes described type VI retrons, in which single-stranded DNA switches on toxin production instead of restraining a ready toxin. On phage infection the DNA accumulates, unblocks translation and the toxin destabilizes the membrane, killing the cell. The study appeared in Molecular Cell.

• Type VI retrons turn on toxin production rather than inhibit a ready toxin
• Phage infection raises single-stranded DNA levels needed for defense
• The toxin is a small protein that embeds in the bacterial membrane
• The team aims to build synthetic sensors, switches and antimicrobials from it