Structural studies put phage defense mystery on the RADAR

Phage restriction by adenosine deaminase acting on RNA (RADAR) is a process by which bacteria may alter their own transcriptome to resist bacteriophage. In this issue of Cell, Duncan-Lowey and Tal et al. and Gao et al. both show RADAR proteins assemble into massive molecular complexes but present distinct views about how these assemblies obstruct phage.