Peptidoglycan Crosslinking Enzyme

Peptidoglycan crosslinking enzymes are essential bacterial enzymes responsible for forming the covalent bonds that link peptidoglycan (PG) strands together, creating a rigid and protective cell wall structure. These enzymes are crucial for bacterial survival, as they provide mechanical strength to withstand internal osmotic pressure and maintain cell shape. There are two main classes: D,D-Transpeptidases (Penicillin-Binding Proteins, PBPs) and L,D-Transpeptidases (Ldts). PBPs catalyze 4-3 peptide crosslinks and are primary targets for β-lactam antibiotics. Ldts catalyze alternative crosslinks and are especially important under antibiotic stress. Inhibition of these enzymes leads to weakened cell walls and cell death, exploited by many antibiotics. Resistance mechanisms include altered enzyme specificity or expression levels.

Other names

Peptidoglycan transpeptidaseD,D-TranspeptidasePenicillin-Binding Protein (PBP)L,D-Transpeptidase (Ldt)

Inhibition of peptidoglycan crosslinking, leading to cell wall weakening and lysis