Biologjia Online

Despite decades of investigation, the mechanisms that control faithful segregation of bacterial chromosomes have remained elusive. Here, Gitai et al. use a combination of pharmacological and biochemical approaches to demonstrate a direct role for the actin-like bacterial cytoskeleton protein MreB. The findings suggest a two-step model for chromosome segregation in Caulobacter crescentus: MreB is essential for segregation of the region of the chromosome nearest the origin of replication, while the rest of the chromosome follows through an MreB-independent mechanism. The use of cytoskeletal elements for bacterial chromosome segregation raises the exciting possibility that bacterial and eukaryotic mitosis share more in common than was ever appreciated.