Persistent super-diffusive motion of Escherichia coli chromosomal loci

Nat Commun. 2014 May 30:5:3854. doi: 10.1038/ncomms4854.

Abstract

The physical nature of the bacterial chromosome has important implications for its function. Using high-resolution dynamic tracking, we observe the existence of rare but ubiquitous 'rapid movements' of chromosomal loci exhibiting near-ballistic dynamics. This suggests that these movements are either driven by an active machinery or part of stress-relaxation mechanisms. Comparison with a null physical model for subdiffusive chromosomal dynamics shows that rapid movements are excursions from a basal subdiffusive dynamics, likely due to driven and/or stress-relaxation motion. Additionally, rapid movements are in some cases coupled with known transitions of chromosomal segregation. They do not co-occur strictly with replication, their frequency varies with growth condition and chromosomal coordinate, and they show a preference for longitudinal motion. These findings support an emerging picture of the bacterial chromosome as off-equilibrium active matter and help developing a correct physical model of its in vivo dynamic structure.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Chromosome Segregation
  • Chromosomes, Bacterial*
  • DNA Replication*
  • Escherichia coli*
  • Genetic Loci
  • Motion*