Peptidoglycan of *Staphylococcus aureus* cell wall

Peptidoglycan of *Staphylococcus aureus* cell wall is the primary structural polymer forming a highly cross-linked network that encapsulates the bacterium, providing mechanical strength, rigidity, and resistance to internal turgor pressure while serving as a scaffold for surface proteins essential for pathogenesis. It consists of short glycan strands of repeating N-acetylglucosamine (GlcNAc) and N-acetylmuramic acid (MurNAc) units connected by species-specific pentaglycine interpeptide bridges, achieving 80-90% cross-linking for a three-dimensional hydrogel-like mesh that enables cell plasticity during growth and division. This structure is dynamically maintained through synthesis by penicillin-binding proteins (PBPs) performing transglycosylation and transpeptidation, alongside hydrolysis by 18 peptidoglycan hydrolases (PGHs) for remodeling, turnover, cell enlargement, septation, and daughter cell separation. In disease, it acts as the key interface with the host during *S. aureus* infections, influencing macrophage fitness, liver colonization, and immune evasion. Its synthesis is a validated therapeutic target for antibiotics like β-lactams and vancomycin, which disrupt final assembly stages, leading to cell wall weakening, hole formation, and bacterial death, though challenges arise from resistance mechanisms such as altered cross-linking or O-acetylation.

Other names

S. aureus peptidoglycanStaphylococcal peptidoglycan

Inhibition of peptidoglycan transglycosylation and polymerization of lipid II substrates; Inhibition of transpeptidation and cross-linking by penicillin-binding proteins (PBPs); Binding to D-Ala-D-Ala termini to prevent peptidoglycan subunit incorporation (vancomycin)