Cell-shape homeostasis in Escherichia coli is driven by growth, division, and nucleoid complexity

Biophys J. 2015 Jul 21;109(2):178-81. doi: 10.1016/j.bpj.2015.06.026.

Abstract

Analysis of recently published high-throughput measurements of wild-type Escherichia coli cells growing at a wide range of rates demonstrates that cell width W, which is constant at any particular growth rate, is related (with a CV = 2.4%) to the level of nucleoid complexity, expressed as the amount of DNA in genome equivalents that is associated with chromosome terminus (G/terC). The relatively constant (CV = 7.3%) aspect ratio of newborn cells (Lb/W) in populations growing at different rates indicates existence of cell-shape homeostasis. Enlarged W of thymine-limited thyA mutants growing at identical rates support the hypothesis that nucleoid complexity actively affects W. Nucleoid dynamics is proposed to transmit a primary signal to the peptidoglycan-synthesizing system through the transertion mechanism, i.e., coupled transcription/translation of genes encoding membrane proteins and inserting these proteins into the membrane.

MeSH terms

  • Cell Division / physiology*
  • Chromosomes, Bacterial
  • Escherichia coli / cytology*
  • Escherichia coli / physiology*
  • Escherichia coli Proteins / metabolism
  • Homeostasis / physiology*
  • Membrane Proteins / metabolism
  • Models, Biological

Substances

  • Escherichia coli Proteins
  • Membrane Proteins