Staphylococcus aureus pentaglycine-crosslinked peptidoglycan (S. aureus PGN)

The Staphylococcus aureus pentaglycine-crosslinked peptidoglycan is a fundamental structural element of the bacterial cell wall, essential for maintaining cell shape and protecting against osmotic lysis (Schleifer & Kandler, 1972). It consists of glycan strands of alternating N-acetylglucosamine and N-acetylmuramic acid, which are uniquely cross-linked by a pentaglycine (Gly5) interpeptide bridge (Turner et al., 2014). This specific cross-link is a hallmark of S. aureus and provides the cell wall with the rigidity required to survive in diverse environments. In the context of disease, this structure is vital for the survival of S. aureus during host infection, contributing to its pathogenicity and resistance to environmental stress (Bastos et al., 2010). It serves as a major therapeutic target; for instance, glycopeptide antibiotics like vancomycin bind to the D-Ala-D-Ala terminus of the peptidoglycan precursor to prevent its incorporation into the wall (Kahne et al., 2005). Furthermore, the enzyme lysostaphin specifically targets the pentaglycine bridge, cleaving it and causing rapid bacterial death. Because the pentaglycine bridge is absent in human cells, it offers a high degree of selectivity for antimicrobial drug development. Understanding the synthesis and regulation of this structure is crucial for addressing the challenge of antibiotic-resistant strains like MRSA and VRSA.

Other names

Pentaglycine bridgeStaphylococcal peptidoglycanMureinGly5-crosslinked peptidoglycanStaphylococcus aureus cell wall

Direct enzymatic cleavage of the pentaglycine interpeptide bridge or steric inhibition of cross-linking by binding to peptidoglycan precursors.