DNA Replication Control Is Linked to Genomic Positioning of Control Regions in Escherichia coli

PLoS Genet. 2016 Sep 2;12(9):e1006286. doi: 10.1371/journal.pgen.1006286. eCollection 2016 Sep.

Abstract

Chromosome replication in Escherichia coli is in part controlled by three non-coding genomic sequences, DARS1, DARS2, and datA that modulate the activity of the initiator protein DnaA. The relative distance from oriC to the non-coding regions are conserved among E. coli species, despite large variations in genome size. Here we use a combination of i) site directed translocation of each region to new positions on the bacterial chromosome and ii) random transposon mediated translocation followed by culture evolution, to show genetic evidence for the importance of position. Here we provide evidence that the genomic locations of these regulatory sequences are important for cell cycle control and bacterial fitness. In addition, our work shows that the functionally redundant DARS1 and DARS2 regions play different roles in replication control. DARS1 is mainly involved in maintaining the origin concentration, whether DARS2 is also involved in maintaining single cell synchrony.

MeSH terms

  • Chromosomes, Bacterial / genetics*
  • DNA Replication / genetics*
  • DNA Transposable Elements / genetics
  • DNA-Binding Proteins / genetics
  • Directed Molecular Evolution*
  • Escherichia coli / genetics
  • Escherichia coli Proteins / genetics*
  • Genetic Fitness
  • Genome, Bacterial / genetics
  • Genomics
  • Regulatory Sequences, Nucleic Acid / genetics
  • Replication Origin / genetics

Substances

  • DNA Transposable Elements
  • DNA-Binding Proteins
  • Escherichia coli Proteins

Grants and funding

This research was part of the Center for Bacterial Stress Response and Persistence (BASP) funded by a grant from the Danish National Research Foundation (DNRF120) and by a grant from the Novo Nordisk Foundation. The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.