Staphylococcus aureus peptidoglycan pentaglycine bridge

The Staphylococcus aureus peptidoglycan pentaglycine bridge is a unique structural component of the bacterial cell wall that cross-links the peptide stems of the peptidoglycan layer (PubMed: 11133902). Unlike many other bacteria that use direct cross-links or shorter bridges, S. aureus utilizes a sequence of five glycine residues to connect the L-lysine of one muropeptide to the D-alanine of an adjacent one (UniProt: P0A0V1). This specific architecture provides the cell wall with the necessary mechanical strength and flexibility to withstand high internal osmotic pressure (StatPearls: NBK441868). Because this pentaglycine bridge is highly characteristic of S. aureus, it serves as a specific target for antimicrobial agents like lysostaphin, a glycylglycine endopeptidase that cleaves the bridge and causes rapid bacterial lysis (PubChem: CID 131676477). Additionally, the enzymes responsible for synthesizing this bridge, such as FemA and FemB, are critical for the expression of methicillin resistance, making the bridge and its biosynthetic pathway attractive targets for overcoming antibiotic resistance (PubMed: 10692356). Disrupting this structure effectively compromises the integrity of the bacterial envelope, leading to cell death. Therapeutic strategies focusing on this target are particularly valuable for treating multi-drug resistant strains like MRSA.

Other names

Pentaglycine interpeptide bridgePentaglycine cross-bridgeGly5 bridgeStaphylococcal pentaglycine bridge

Direct enzymatic cleavage of the glycyl-glycine bonds within the pentaglycine bridge (e.g., by lysostaphin) or inhibition of the enzymes (FemX, FemA, FemB) responsible for the sequential addition of glycine residues during bridge synthesis (PubMed: 10692356, PubChem: CID 131676477).