Abstract
EMBO J (2013) 32 9, 1238–1249. doi:; DOI: 10.1038/emboj.2013.34 Remarkably little is known about how bacterial chromosomes and their plasmids are partitioned to daughter cells prior to cell division, despite extensive experimentation and bioinformatic analysis. An in vitro study described in the current issue of The EMBO Journal recapitulates many features of plasmid partition in vivo and provides insight into how protein patterning on the nucleoid, determined by a diffusion-ratchet mechanism, directs plasmid positioning and partition. Related protein complexes likely use the same mechanism to position and partition newly replicated sister chromosomes and large protein complexes that act in processes other than chromosome segregation.