The peptidoglycan wall, located in the periplasm between the inner and outer membranes of the cell envelope in Gram-negative bacteria, maintains cell shape and endows osmotic robustness. Predatory Bdellovibrio bacteria invade the periplasm of other bacterial prey cells, usually crossing the peptidoglycan layer, forming transient structures called bdelloplasts within which the predators replicat...

The peptidoglycan layer of a marine pseudomonad was observed by electron microscopy in thin sections of plasmolyzed intact cells and mureinoplasts but not in untreated intact cells. Only fragments of this layer could be isolated by sodium lauryl sulfate (SLS) treatment of mureinoplast envelopes. Sacculus-like peptidoglycan structures were obtained from growing cells by immediate heat inactivati...

Fluorescent d-amino acids (FDAAs) enable efficient in situ labeling of peptidoglycan in diverse bacterial species. Conducted by enzymes involved in peptidoglycan biosynthesis, FDAA labeling allows specific probing of cell wall formation/remodeling activity, bacterial growth and cell morphology. Their broad application and high biocompatibility have made FDAAs an important and effective tool for...

Peptidoglycan synthesis and its fine chemical composition were studied in dividing cocci of Escherichia coli carrying the lov-1 mutation and in which the coccal shape was obtained either by mecillinam treatment or by transferring a pbpA mutation (penicillin-binding protein 2- phenotype), as compared to normal rods and non-dividing cocci. Synchronously dividing cocci showed peptidoglycan synthes...

Vegetative cells of Myxococcus xanthus (strain FB) were induced to form myxospores by the glycerol induction technique. Several structural changes took place in the peptidoglycan during myxospore formation. The percent of the peptidoglycan comprised of monomer (disaccharide peptide) decreased from about 20% to approximately 7%. The proportion of the total diaminopimelic acid possessing a free a...

In Selenomonas ruminantium, a strictly anaerobic and gram-negative bacterium, cadaverine covalently linked to the peptidoglycan is required for the interaction between the peptidoglycan and the S-layer homologous (SLH) domain of the major outer membrane protein Mep45. Here, using a series of diamines with a general structure of NH(3)(+)(CH(2))(n)NH(3)(+) (n = 3 to 6), we found that cadaverine (...

Carbohydrate recognition is essential for growth, cell adhesion and signalling in all living organisms. A highly conserved carbohydrate binding module, LysM, is found in proteins from viruses, bacteria, fungi, plants and mammals. LysM modules recognize polysaccharides containing N-acetylglucosamine (GlcNAc) residues including peptidoglycan, an essential component of the bacterial cell wall. How...

Gram-negative bacteria produce outer membrane vesicles (OMVs) that package and deliver proteins, small molecules, and DNA to prokaryotic and eukaryotic cells. The molecular details of OMV biogenesis have not been fully elucidated, but peptidoglycan-associated outer membrane proteins that tether the outer membrane to the underlying peptidoglycan have been shown to be critical for OMV formation i...

Multiple sclerosis is believed to result from a CD4+ T-cell response against myelin antigens. Peptidoglycan, a major component of the Gram-positive bacterial cell wall, is a functional lipopolysaccharide analogue with potent proinflammatory properties and is conceivably a mediator of sterile inflammation. Here we demonstrate that peptidoglycan is present within antigen-presenting cells in the b...

During the initial stages of intraperiplasmic growth of Bdellovibrio bacteriovorus on Escherichia coli, the peptidoglycan of the E. coli becomes acylated with long-chain fatty acids, primarily palmitic acid (60%) and oleic acid (20%). The attachment of the fatty acids to the peptidoglycan involves a carboxylic-ester bond, i.e., they were removed by treatment with alkaline hydroxylamine. Their l...