Self-organised segregation of bacterial chromosomal origins
Abstract
The chromosomal replication origin region (ori) of characterized bacteria is dynamically positioned throughout the cell cycle. In slowly growing Escherichia coli, ori is maintained at mid-cell from birth until its replication, after which newly replicated sister oris move to opposite quarter positions. Here, we provide an explanation for ori positioning based on the self-organisation of the Structural Maintenance of Chromosomes complex, MukBEF, which forms dynamically positioned clusters on the chromosome. We propose that a non-trivial feedback between the self-organising gradient of MukBEF complexes and the oris leads to accurate ori positioning. We find excellent agreement with quantitative experimental measurements and confirm key predictions. Specifically, we show that oris exhibit biased motion towards MukBEF clusters, rather than mid-cell. Our findings suggest that MukBEF and oris act together as a self-organising system in chromosome organisation-segregation and introduces protein self-organisation as an important consideration for future studies of chromosome dynamics.
Data availability
Experimental source data files have been provided for Figure 1. We also used the ori localisation tracks provided as supplementary data to Kuwada et al., 2014 and the co-localisation curves from Figure 1c of Nolivos et al., 2016.
Article and author information
Author details
Funding
Wellcome (DSJ: 200782/Z/16/Z)
- Jarno Mäkelä
- David J Sherratt
Deutsche Forschungsgemeinschaft (GSC 220)
- Andreas Hofmann
Max-Planck-Gesellschaft (Open-access funding)
- Sean M Murray
Human Frontier Science Program (RGP0014/2014)
- Andreas Hofmann
Deutsche Forschungsgemeinschaft (INST 35/1134-1 FUGG)
- Andreas Hofmann
- Dieter Heermann
The funders had no role in study design, data collection and interpretation, or the decision to submit the work for publication.
Copyright
© 2019, Hofmann et al.
This article is distributed under the terms of the Creative Commons Attribution License permitting unrestricted use and redistribution provided that the original author and source are credited.
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