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Bacterial cell wall. MurJ is the flippase of lipid-linked precursors for peptidoglycan biogenesis

Lok-To Sham1, Emily K Butler2, Matthew D Lebar3

  • 1Department of Microbiology and Immunobiology, Harvard Medical School, Boston, MA 02115, USA.

Science (New York, N.Y.)
|July 12, 2014
PubMed

Insights

Researchers identified MurJ as the essential flippase for lipid II, a key component in bacterial cell wall (peptidoglycan) synthesis. This discovery advances understanding of antibiotic targets for combating bacterial infections.

Area of Science:

  • Microbiology
  • Molecular Biology
  • Biochemistry

Background:

  • Peptidoglycan (PG) is crucial for bacterial cell integrity, protecting against osmotic lysis.
  • Inhibiting PG biogenesis is a validated antibiotic strategy.
  • Lipid II is the essential precursor for PG assembly, requiring translocation across the cytoplasmic membrane.

Purpose of the Study:

  • To identify the enzyme responsible for translocating Lipid II across the cytoplasmic membrane.
  • To validate the function of this enzyme in peptidoglycan polymerization.

Main Methods:

  • Development of a novel assay to measure Lipid II flippase activity.
  • Application of a chemical genetic strategy to specifically inhibit flippase function.
  • Integration of assay and genetic approaches to pinpoint the flippase.

Main Results:

  • The study successfully identified and characterized the enzyme MurJ.
  • MurJ was confirmed to be the essential flippase responsible for Lipid II translocation in Escherichia coli.
  • Blocking MurJ function effectively inhibited peptidoglycan synthesis.

Conclusions:

  • MurJ is the essential Lipid II flippase in Escherichia coli.
  • Understanding MurJ's role provides a new target for antibacterial drug development.
  • This finding deepens insights into the final steps of bacterial cell wall synthesis.

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