Penicillin-binding protein 1 (PBP1)

Penicillin-binding proteins are a family of enzymes found in bacteria that play essential roles in the final stages of peptidoglycan synthesis during cell wall formation. They are named for their ability to bind penicillins and related β-lactam antibiotics.\n\n**Penicillin-binding protein 1** is typically a bifunctional enzyme with both transglycosylase and transpeptidase activities involved in polymerizing glycan strands and cross-linking peptide chains within the bacterial cell wall. **Penicillin-binding protein 3** is primarily a transpeptidase critical for septum formation during bacterial cell division; its inhibition leads to filamentation or failure of proper cytokinesis. **Penicillin-binding protein 4** generally acts as a carboxypeptidase or endopeptidase involved in remodeling peptidoglycan but is not always essential.\n\nThese proteins are major targets for β-lactam antibiotics such as penicillins and cephalosporins. Inhibition disrupts bacterial growth by preventing proper construction of the cell wall, ultimately causing osmotic lysis. Resistance can arise through mutations that reduce antibiotic binding affinity or via acquisition of alternative PBPs with low affinity for β-lactams.\n\nThe term "Penicillin-binding protein 1/3/4" refers collectively to several distinct but related enzymes rather than one specific molecule; each has unique structural features and biological roles depending on species context[2][4]. The grouping may be too broad or ambiguous if precise molecular targeting information is needed.\n\n---\n\n**Note:** \nThere is something incorrect about this target name as written ("Penicillin-binding protein 1/3/4"): it combines multiple distinct proteins into one entry rather than specifying an individual canonical form. For structured data purposes, these should be separated into "Penicillin-binding protein 1", "Penicillin-binding protein 3", etc., each with their own attributes[2][4].

Other names

Penicillin-binding protein 3 (PBP3)Penicillin-binding protein 4 (PBP4)PBPsPBP1a, PBP1b (for specific isoforms in some species)

Covalent inhibition of transpeptidase activity by β-lactam antibiotics; these drugs bind to the active site serine residue and inactivate the enzyme required for cross-linking peptidoglycan strands, leading to cell lysis and death.