Maintaining network security: how macromolecular structures cross the peptidoglycan layer

FEMS Microbiol Lett. 2011 May;318(1):1-9. doi: 10.1111/j.1574-6968.2011.02228.x. Epub 2011 Mar 14.


Peptidoglycan plays a vital role in bacterial physiology, maintaining cell shape and resisting cellular lysis from high internal turgor pressures. Its integrity is carefully maintained by controlled remodeling during growth and division by the coordinated activities of penicillin-binding proteins, lytic transglycosylases, and N-acetylmuramyl-l-alanine amidases. However, its small pore size (∼2 nm) and covalently closed structure make it a formidable barrier to the assembly of large macromolecular cell-envelope-spanning complexes involved in motility and secretion. Here, we review the strategies used by Gram-negative bacteria to assemble such macromolecular complexes across the peptidoglycan layer, while preserving its essential structural role. In addition, we discuss evidence that suggests that peptidoglycan can be integrated into cell-envelope-spanning complexes as a structural and functional extension of their architecture.

Publication types

  • Research Support, Non-U.S. Gov't
  • Review

MeSH terms

  • Biological Transport
  • Cell Wall / chemistry
  • Cell Wall / metabolism
  • Gram-Negative Bacteria / chemistry
  • Gram-Negative Bacteria / metabolism*
  • Macromolecular Substances / metabolism*
  • Peptidoglycan / chemistry*
  • Peptidoglycan / metabolism


  • Macromolecular Substances
  • Peptidoglycan