Staphylococcus aureus peptidoglycan pentaglycine cross-bridge (Pentaglycine bridge)

The Staphylococcus aureus peptidoglycan pentaglycine cross-bridge is a specialized structural component of the bacterial cell wall that provides essential mechanical stability. It consists of a chain of five glycine residues that cross-links the peptide stems of the peptidoglycan polymer, specifically connecting the L-lysine of one chain to the D-alanine of another (PMID: 10913072). This high degree of cross-linking allows S. aureus to maintain its shape and resist high internal osmotic pressures. Because this pentaglycine bridge is relatively unique to S. aureus and a few other staphylococcal species, it represents a highly specific target for antimicrobial therapy. The most prominent drug interacting with this target is lysostaphin, an endopeptidase that specifically cleaves the glycyl-glycine bonds within the bridge, leading to rapid cell lysis (PMID: 24563513). Additionally, the enzymes responsible for synthesizing this bridge, such as FemA and FemB, are targets for research into overcoming antibiotic resistance, as modifications to the bridge length can confer resistance to certain agents (PMID: 15105405).

Other names

Pentaglycine interpeptide bridgeGly5 cross-bridgePeptidoglycan cross-linkStaphylococcal pentaglycine bridge

Direct cleavage of glycyl-glycine bonds by endopeptidases (e.g., lysostaphin) or inhibition of the transpeptidation process that incorporates these bridges into the mature peptidoglycan layer (PMID: 24563513, PMID: 15105405).