Robustness and accuracy of cell division in Escherichia coli in diverse cell shapes

Proc Natl Acad Sci U S A. 2012 May 1;109(18):6957-62. doi: 10.1073/pnas.1120854109. Epub 2012 Apr 16.

Abstract

Cell division in typical rod-shaped bacteria such as Escherichia coli shows a remarkable plasticity in being able to adapt to a variety of irregular cell shapes. Here, we investigate the roles of the Min system and the nucleoid-occlusion factor SlmA in supporting this adaptation. We study "squeezed" E. coli in narrow nanofabricated channels where these bacteria exhibit highly irregular shapes and large volumes. Despite the severely anomalous morphologies we find that most of these bacteria maintain their ability to divide into two equally sized daughters with an accuracy comparable to that of normal rod-shaped cells (about 4%). Deletion of either slmA or minC shows that the molecular systems associated with these genes are largely dispensable for accurate cell division in these irregular cell shapes. Using fluorescence time-lapse microscopy, we determine that the functionality of the Min system is affected by the cell shape, whereas the localization of a nucleoid relative to the cell division proteins (the divisome) remains unperturbed in a broad spectrum of morphologies, consistent with nucleoid occlusion. The observed positioning of the nucleoid relative to the divisome appears not to be affected by the nucleoid-occlusion factor SlmA. The current study underscores the importance of nucleoid occlusion in positioning the divisome and shows that it is robust against shape irregularities.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adenosine Triphosphatases / genetics
  • Adenosine Triphosphatases / physiology
  • Bacterial Proteins / genetics
  • Bacterial Proteins / physiology
  • Biophysical Phenomena
  • Carrier Proteins / genetics
  • Carrier Proteins / physiology
  • Cell Division / genetics
  • Cell Division / physiology*
  • Cytoskeletal Proteins / genetics
  • Cytoskeletal Proteins / physiology
  • DNA-Binding Proteins
  • Escherichia coli K12 / cytology*
  • Escherichia coli K12 / genetics
  • Escherichia coli K12 / physiology*
  • Escherichia coli Proteins / genetics
  • Escherichia coli Proteins / physiology
  • Gene Deletion
  • Genes, Bacterial
  • Green Fluorescent Proteins / genetics
  • Green Fluorescent Proteins / metabolism
  • Membrane Proteins / genetics
  • Membrane Proteins / physiology
  • Microfluidic Analytical Techniques / instrumentation
  • Microscopy, Fluorescence
  • Recombinant Fusion Proteins / genetics
  • Recombinant Fusion Proteins / metabolism
  • Time-Lapse Imaging

Substances

  • Bacterial Proteins
  • Carrier Proteins
  • Cytoskeletal Proteins
  • DNA-Binding Proteins
  • Escherichia coli Proteins
  • FtsZ protein, Bacteria
  • Membrane Proteins
  • MinC protein, E coli
  • Recombinant Fusion Proteins
  • SlmA protein, E coli
  • hupA protein, E coli
  • Green Fluorescent Proteins
  • Adenosine Triphosphatases
  • MinD protein, E coli