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Updated: Mar 9, 2026

X-Ray Crystallography to Study the Oligomeric State Transition of the Thermotoga maritima M42 Aminopeptidase TmPep1050
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X-Ray Crystallography to Study the Oligomeric State Transition of the Thermotoga maritima M42 Aminopeptidase TmPep1050

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Crystal structure of the MOP flippase MurJ in an inward-facing conformation

Alvin C Y Kuk1, Ellene H Mashalidis1, Seok-Yong Lee1

  • 1Department of Biochemistry, Duke University School of Medicine, Durham, North Carolina, USA.

Nature Structural & Molecular Biology
|December 27, 2016
PubMed

Insights

Researchers reveal the structure of bacterial peptidoglycan flippase MurJ, uncovering a potential mechanism for lipid II transport essential for bacterial cell wall synthesis and antibiotic development.

Area of Science:

  • Microbiology
  • Structural Biology
  • Biochemistry

Background:

  • Peptidoglycan (PG) is crucial for bacterial cell integrity, protecting against osmotic lysis.
  • PG biosynthesis is a validated target for novel antibiotics.
  • MurJ, a member of the MOP transporter superfamily, is responsible for flipping the PG precursor, lipid II, across the cell membrane.

Purpose of the Study:

  • To elucidate the structural basis of MurJ function in lipid II transport.
  • To gain insights into the mechanism of MOP transporters.

Main Methods:

  • X-ray crystallography was employed to determine the structure of Thermosipho africanus MurJ.
  • The structure was resolved at 2.0-Å resolution, revealing an inward-facing conformation.

Main Results:

  • The crystal structure of MurJ reveals a unique architecture with a hydrophobic groove leading to a cationic central cavity.
  • This structure suggests an alternating access mechanism for lipid II translocation.
  • This is the first structural insight into MurJ function.

Conclusions:

  • The determined structure provides a mechanistic hypothesis for MurJ-mediated lipid II flipping.
  • The findings may offer broader implications for understanding other MOP superfamily transporters.
  • This structural information could aid in the design of new antibiotics targeting bacterial cell wall synthesis.

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