An enzyme inside the bacterial-cell membrane chops up viral DNA on entry

Nature, Published online: 18 March 2026; doi:10.1038/d41586-026-00732-4When a virus infects a bacterial cell, the viral genome is the first component to be fully injected into the cell, making it an ideal immune target. A bacterial enzyme anchored to the membrane intercepts and cleaves viral DNA during injection, providing a powerful form of antiviral defence.