<p>Penicillin-binding proteins are beta-lactam antibiotic-sensitive bacterial enzymes required for the growth and maintenance of the peptidoglycan layer of the bacterial cell wall that protects the cell from osmotic stress. Penicillin-binding protein 4 (PBP4) functions as a transpeptidase, and belongs to MEROPS peptidase family S11 (clan SE). PBP4 acts co-operatively with PBP2 in staphylococcal cell wall biosynthesis and susceptibility to antimicrobial agents [<cite idref="PUB00035543"/>]. This entry represents the C-terminal domain PBP4.</p> Penicillin-binding protein 4, C-terminal