Matrix protein (36,500 daltons), one of the major polypeptides of the Escherichia coli cell envelope, is arranged in a periodic monolayer which covers the outer surface of the peptidoglycan. Although its association with the peptidoglycan layer is probably tight, the periodic structure of the peptidoglycan. Although its association with the peptidoglycan later is probably tight, the periodic st...

Identification of the full complement of peptidoglycan hydrolases detected by zymogram in Enterococcus faecalis extracts led to the characterization of two novel hydrolases that we named AtlB and AtlC. Both enzymes have a similar modular organization comprising a central catalytic domain fused to two LysM peptidoglycan-binding modules. AtlB and AtlC displayed N-acetylmuramidase activity, as dem...

Growing bacterial L forms are reputed to lack peptidoglycan, although cell division is normally inseparable from septal peptidoglycan synthesis. To explore which cell division functions L forms use, we established a protocol for quantitatively converting a culture of a wild-type Escherichia coli K-12 strain overnight to a growing L-form-like state by use of the beta-lactam cefsulodin, a specifi...

Bacillus anthracis spores, the infectious agents of anthrax, are notoriously difficult to remove from contaminated areas because they are resistant to many eradication methods. These resistance properties are due to the spore's dehydration and dormancy and to the multiple protective layers surrounding the spore core, one of which is the cortex. In order for B. anthracis spores to germinate and ...

In this study, global intra- and extracellular metabolic profiles were exploited to investigate the impact of antibiotic compounds with different cellular targets on the metabolome of Staphylococcus aureus HG001. Primary metabolism was largely covered, yet uncommon staphylococcal metabolites were detected in the cytosol of S. aureus, including sedoheptulose-1,7-bisphosphate and the UDP-MurNAc-p...

The high molecular weight penicillin-binding proteins (PBP(s) ) Bacillus subtilis PBPs 1, 2, and 4 and Bacillus stearothermophilus PBPs 1-4 were shown to catalyze peptidoglycan synthesis from the undecaprenol-containing lipid intermediate substrate in two assay systems. In a filter paper assay system, high levels of substrate polymerization occurred when reaction mixtures were incubated on What...

Upon nutrient limitation cells of the swarming soil bacterium Myxococcus xanthus form a multicellular fruiting body in which a fraction of the cells develop into myxospores. Spore development includes the transition from a rod-shaped vegetative cell to a spherical myxospore and so is expected to be accompanied by changes in the bacterial cell envelope. Peptidoglycan is the shape-determining str...

Lipopolysaccharide induces TLR-1-8 mRNAs over-expression in corneal fibroblast. Analyzing if other TLR-ligands can do the same, we found that peptidoglycan does, but not muramyldipeptide, lipoteichoic acid and polyI:C. This suggests that the recognition of lipopolysaccharide and peptidoglycan is enough to alert these cells against microorganisms through the over-expression of the majority TLRs.

Staphylococcus aureus is one of the most significant pathogens in human sepsis and endocarditis. S. aureus can initiate blood coagulation, leading to the formation of microthrombi and multiorgan dysfunction in sepsis, whereas in endocarditis the bacterium induces fibrin clots on the inner surface of the heart, so-called endocardial vegetations. In the present study, we show that live and heat-k...

Peptidoglycan (murein) is a major essential and specific constituent of the bacterial cell wall. Its main function is to protect cells against the internal osmotic pressure and to maintain the characteristic cell shape. It also serves as a platform for the anchoring of specific proteins and other cell wall components. This giant macromolecule is composed of long glycan chains cross-linked by sh...