Strand separation establishes a sustained lock at the Tus–Ter replication fork barrier

A single-molecule approach using magnetic tweezers shows that DNA strand separation alone can trigger a lock at Tus–Ter sites where oppositely moving replisomes on circular bacterial chromosomes must avoid crashing. Tremani has become trained in interactions between enzymes and DNA. In this case the DNA acts as a lock, and can be unlocked to separate DNA strands. We refrained from the idea of actually visualising a keyhole and key in the end, and stuck with the more 'realistic' imagery.