Pathogenic enterococci are becoming resistant to currently available antibiotics, including vancomycin, the drug of last resort for Gram-positive infections. Enterococci pose a significant public health threat, not least because of the risk of transferring vancomycin resistance to the ubiquitous Staphylococcus aureus. Vancomycin resistance is manifested by cell wall peptidoglycan precursors wit...

Escherichia coli, and presumably most other gram-negative bacteria, possesses an efficient protein machinery for recycling its peptidoglycan during cell growth. The major recycled peptidoglycan product is N-acetylglucosamine-1,6-anhydro-N-acetylmuramic acid-tetrapeptide. Its uptake from the periplasm into the cytoplasm is carried out via the AmpG protein, an intrinsic membrane protein. In gram-...

We report a theoretical calculation of the elasticity of the peptidoglycan network, the only stress-bearing part of rod-shaped Gram-negative eubacteria. The peptidoglycan network consists of elastic peptides and inextensible glycan strands, and it has been proposed that the latter form zigzag filaments along the circumference of the cylindrical bacterial shell. The zigzag geometry of the glycan...

Rising cases of antibiotic-resistant bacteria is a public health concern. Many approved antibiotics target penicillin-binding proteins example peptidoglycan transpeptidase (PTPase). Due to wide pharmacological activity of phenothiazines, new styryl, aryl, alkynyl, and thiophenyl benzo[a]phenothiazines were synthesized and their inhibitory potency against PTPasein silico and Gram-po...

The peptidoglycan cell wall is an integral organelle critical for bacterial cell shape and stability. Proper cell wall construction requires the interaction of synthesis enzymes and the cytoskeleton, but it is unclear how the activities of individual proteins are coordinated to preserve the morphology and integrity of the cell wall during growth. To elucidate this coordination, we used single-m...

The biochemical phenotype of rodA mutants was not affected by the simultaneous presence in double mutants of the lyt gene which makes them 90 to 95% deficient in autolysin action. The only morphological effect of this deficiency on the expression of the rod gene was that both the rod and the coccal forms of the mutant failed to separate and grew as long chains of cells. Inhibition of protein sy...

Background Lipopolysaccharide (LPS) and peptidoglycan are microbial products recognized by Toll-like receptor-4 (TLR4) and nucleotide-binding oligomerization domain 1 (NOD1) and NOD2, respectively. LPS has been found to cause behavioural alterations indicative of sickness and depressed mood. The effect of peptidoglycan on exploratory and affective behaviour has not yet been explored, although i...

An oligomeric intermediate in the biosynthetic pathway of peptidoglycan was isolated from B. megaterium. The oligomer has been identified as [disaccharide(pentapeptide)]12 pyrophosphoryl undecaprenol.

Peptidoglycan (PGN) recognition proteins (PGRPs) are pattern-recognition receptors of the innate immune system that bind and, in some cases, hydrolyze bacterial PGNs. We determined the crystal structure, at 2.30-A resolution, of the C-terminal PGN-binding domain of human PGRP-Ialpha in complex with a muramyl tripeptide representing the core of lysine-type PGNs from Gram-positive bacteria. The p...

The innate immune system constitutes the first line of defense against microorganisms in both vertebrates and invertebrates. Although much progress has been made toward identifying key receptors and understanding their role in host defense, far less is known about how these receptors recognize microbial ligands. Such studies have been severely hampered by the need to purify ligands from microbi...