DNA, a long linear molecule, is the carrier of genetic information. In the cell, each DNA molecule is packaged in a structure called chromosome. The ends of linear chromosomes are capped by structures known as telomeres to prevent fusion with neighboring chromosomes. Telomeres are maintained by an enzyme called telomerase during DNA replication. In order to do so, telomerase has to find the telomere region on DNA quickly and precisely. One telomerase is the protelomerase TelK, which binds to the ends of DNA, cleaves DNA strands and refolds cleaved DNA ends into hairpin telomeres in linear chromosomes of prokaryotes and viruses. Previous studies have shown that TelK is only active as a dimer. In a recent study, researchers investigated the target-search mechanism of protelomerase TelK through single-molecule experiments and molecular dynamics simulation. It was revealed that as a monomer, TelK undergoes one-dimensional diffusion along non-specific DNA (without telomere sequence), and is able to bind to the target site preferentially. There, the target-immobilized monomer waits for a second binding partner to form an active protein complex. More on our TelK website.