Cell wall elongation mode in Gram-negative bacteria is determined by peptidoglycan architecture

Nat Commun. 2013;4:1496. doi: 10.1038/ncomms2503.

Abstract

Cellular integrity and morphology of most bacteria is maintained by cell wall peptidoglycan, the target of antibiotics essential in modern healthcare. It consists of glycan strands, cross-linked by peptides, whose arrangement determines cell shape, prevents lysis due to turgor pressure and yet remains dynamic to allow insertion of new material, and hence growth. The cellular architecture and insertion pattern of peptidoglycan have remained elusive. Here we determine the peptidoglycan architecture and dynamics during growth in rod-shaped Gram-negative bacteria. Peptidoglycan is made up of circumferentially oriented bands of material interspersed with a more porous network. Super-resolution fluorescence microscopy reveals an unexpected discontinuous, patchy synthesis pattern. We present a consolidated model of growth via architecture-regulated insertion, where we propose only the more porous regions of the peptidoglycan network that are permissive for synthesis.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Cell Wall / metabolism*
  • Cell Wall / ultrastructure
  • Escherichia coli / chemistry
  • Escherichia coli / cytology
  • Escherichia coli / ultrastructure
  • Gram-Negative Bacteria / chemistry*
  • Gram-Negative Bacteria / cytology*
  • Gram-Negative Bacteria / ultrastructure
  • Microscopy, Atomic Force
  • Microscopy, Fluorescence
  • Models, Molecular
  • Muramidase / metabolism
  • Peptidoglycan / chemistry*
  • Vancomycin / metabolism

Substances

  • Peptidoglycan
  • Vancomycin
  • Muramidase