Nonrandom segregation of sister chromosomes by <i>Escherichia coli</i> MukBEF
Jarno Mäkelä, Stephan Uphoff, David J. Sherratt
Abstract
Significance Circular chromosomes in rod-shaped bacteria exist inside a cell in two distinct configurations, “transverse” and “longitudinal,” relative to the long cell axis, with chromosomal loci occupying specific cellular locations in both cases. Bacteria with longitudinal chromosome organization (e.g., Caulobacter crescentus ) typically tether their origins of replication to the cell membrane and do not undergo overlapping rounds of replication. In contrast, bacteria with transverse organization (e.g., Escherichia coli ) orient their chromosomes by an unknown mechanism and have lifestyles compatible with overlapping rounds of replication. Here, we address the relative roles of two major players in chromosome organization–segregation and propose a model of how E. coli maintains chromosome conformation and orientation inside cells and how this organization is propagated over generations.