Penicillin-binding protein, transpeptidase (IPR001460)

Short name: PCN-bd_Tpept

Overlapping homologous superfamilies


Domain relationships



This signature identifies a large group of proteins, which include:

  • Beta-lactamase precursor (EC:, penicillinase)
  • Peptidoglycan synthetase ftsI (EC:, peptidoglycan glycosyltransferase 3)
  • Methicillin resistance mecR1 protein
  • Methicillin resistance blaR1 protein

The large number of penicillin binding proteins, which are represented in this group of sequences, are responsible for the final stages of peptidoglycan biosynthesis for cell wall formation. The proteins synthesise cross-linked peptidoglycan from lipid intermediates, and contain a penicillin-sensitive transpeptidase carboxy-terminal domain. The active site serine (residue 337 in P14677) is conserved in all members of this family [PMID: 8605631].

MecR1 and BlaR1 are metallopeptidases belonging to MEROPS peptidase family M56, clan M-. BlaR1 and MecR1 cleave their cognate transcriptional repressors BlaI and MecI, respectively, activating the synthesis of MecA.

MecR1 is present in Staphylococcus aureus and Staphylococcus sciuri, whereas BlaR1 (also known as BlaR, PenR1, or PenJ) has been found in Bacillus licheniformis, Staphylococcus epidermidis, Staphylococcus haemolyticus, and several S. aureus strains. These proteins are either plasmid-encoded, chromosomal, or transposon-mediated. MecR1/BlaR1 proteins are made up by homologous N-terminal 330-residue transmembrane metallopeptidase domains linked to extracellular 260-residue homologous PBP-like penicillin sensor moieties.

GO terms

Biological Process

No terms assigned in this category.

Molecular Function

GO:0008658 penicillin binding

Cellular Component

No terms assigned in this category.

Contributing signatures

Signatures from InterPro member databases are used to construct an entry.