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

ABSTRACT: Peptidoglycan (PG) is a polysaccharide matrix that protects bacteria from osmotic lysis. Inhibition of its biogenesis is a proven strategy for killing bacteria with antibiotics. The assembly of PG requires disaccharide-pentapeptide building blocks attached to a polyisoprene lipid carrier called lipid II. Although the stages of lipid II synthesis are known, the identity of the essential flippase that translocates it across the cytoplasmic membrane for PG polymerization is unclear. We developed an assay for lipid II flippase activity and used a chemical genetic strategy to rapidly and specifically block flippase function. We combined these approaches to demonstrate that MurJ is the lipid II flippase in Escherichia coli.

SUBMITTER: Sham LT

PROVIDER: S-EPMC4163187 | biostudies-literature | 2014 Jul

REPOSITORIES: biostudies-literature

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

Sham Lok-To LT Butler Emily K EK Lebar Matthew D MD Kahne Daniel D Bernhardt Thomas G TG Ruiz Natividad N

Science (New York, N.Y.) 20140701 6193

Peptidoglycan (PG) is a polysaccharide matrix that protects bacteria from osmotic lysis. Inhibition of its biogenesis is a proven strategy for killing bacteria with antibiotics. The assembly of PG requires disaccharide-pentapeptide building blocks attached to a polyisoprene lipid carrier called lipid II. Although the stages of lipid II synthesis are known, the identity of the essential flippase that translocates it across the cytoplasmic membrane for PG polymerization is unclear. We developed an ...[more]

PMID: 25013077

Similar Datasets

MurJ and a novel lipid II flippase are required for cell wall biogenesis in Bacillus subtilis.

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Bioinformatics identification of MurJ (MviN) as the peptidoglycan lipid II flippase in Escherichia coli.

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Lipid-linked cell wall precursors regulate membrane association of bacterial actin MreB.

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The bacterial lipid II flippase MurJ functions by an alternating-access mechanism.

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Structure and Mechanism of the Lipid Flippase MurJ.

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A Burkholderia cenocepacia MurJ (MviN) homolog is essential for cell wall peptidoglycan synthesis and bacterial viability.

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Streptococcus pyogenes YtgP (Spy_0390) complements Escherichia coli strains depleted of the putative peptidoglycan flippase MurJ.

Project description: Not available

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Structure and mutagenic analysis of the lipid II flippase MurJ from Escherichia coli.

Project description:The peptidoglycan cell wall provides an essential protective barrier in almost all bacteria, defining cellular morphology and conferring resistance to osmotic stress and other environmental hazards. The precursor to peptidoglycan, lipid II, is assembled on the inner leaflet of the plasma membrane. However, peptidoglycan polymerization occurs on the outer face of the plasma membrane, and lipid II must be flipped across the membrane by the MurJ protein before its use in peptidoglycan synthesis. Due to its central role in cell wall assembly, MurJ is of fundamental importance in microbial cell biology and is a prime target for novel antibiotic development. However, relatively little is known regarding the mechanisms of MurJ function, and structural data for MurJ are available only from the extremophile Thermosipho africanus Here, we report the crystal structure of substrate-free MurJ from the gram-negative model organism Escherichia coli, revealing an inward-open conformation. Taking advantage of the genetic tractability of E. coli, we performed high-throughput mutagenesis and next-generation sequencing to assess mutational tolerance at every amino acid in the protein, providing a detailed functional and structural map for the enzyme and identifying sites for inhibitor development. Lastly, through the use of sequence coevolution analysis, we identify functionally important interactions in the outward-open state of the protein, supporting a rocker-switch model for lipid II transport.

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