Crystal structure of penicillin-binding protein 3 (PBP3) from Escherichia coli

PLoS One. 2014 May 29;9(5):e98042. doi: 10.1371/journal.pone.0098042. eCollection 2014.


In Escherichia coli, penicillin-binding protein 3 (PBP3), also known as FtsI, is a central component of the divisome, catalyzing cross-linking of the cell wall peptidoglycan during cell division. PBP3 is mainly periplasmic, with a 23 residues cytoplasmic tail and a single transmembrane helix. We have solved the crystal structure of a soluble form of PBP3 (PBP3(57-577)) at 2.5 Å revealing the two modules of high molecular weight class B PBPs, a carboxy terminal module exhibiting transpeptidase activity and an amino terminal module of unknown function. To gain additional insight, the PBP3 Val88-Ser165 subdomain (PBP3(88-165)), for which the electron density is poorly defined in the PBP3 crystal, was produced and its structure solved by SAD phasing at 2.1 Å. The structure shows a three dimensional domain swapping with a β-strand of one molecule inserted between two strands of the paired molecule, suggesting a possible role in PBP3(57-577) dimerization.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Catalytic Domain
  • Escherichia coli Proteins / chemistry*
  • Escherichia coli Proteins / genetics
  • Escherichia coli Proteins / isolation & purification
  • Escherichia coli Proteins / metabolism
  • Escherichia coli* / genetics
  • Escherichia coli* / metabolism
  • Models, Molecular
  • Penicillin-Binding Proteins / chemistry*
  • Penicillin-Binding Proteins / genetics
  • Penicillin-Binding Proteins / isolation & purification
  • Penicillin-Binding Proteins / metabolism
  • Peptidoglycan Glycosyltransferase / chemistry*
  • Peptidoglycan Glycosyltransferase / genetics
  • Peptidoglycan Glycosyltransferase / isolation & purification
  • Peptidoglycan Glycosyltransferase / metabolism
  • Protein Binding
  • Protein Conformation
  • Protein Interaction Domains and Motifs
  • Protein Multimerization


  • Escherichia coli Proteins
  • FtsI protein, E coli
  • Penicillin-Binding Proteins
  • Peptidoglycan Glycosyltransferase

Grant support

This work was supported in part by the Belgian Program on Interuniversity Poles of Attraction initiated by the Belgian State, Prime Minister’s Office, Science Policy programming (IAP no. P6/19), the Fonds de la Recherche Scientifique, (IISN 4.4505.09, IISN 4.4509.11, FRFC 2.4511.06F), the University of Liège (Fonds spéciaux, Crédit classique, C-06/19 and C-09/75), and a return grant to AD. M. J. is recipient of a FRIA (Fonds de la Recherche pour l’Industrie et l’Agriculture) fellowship (F.R.S.-FNRS, Brussels, Belgium). FK is research associates of the FRS-FNRS, Belgium. Jacques Dumas is employed by Sanofi-Aventis. Sanofi-Aventis provided support in the form of salary for author JD, but did not have any additional role in the study design, data collection and analysis, decision to publish, or preparation of the manuscript. The specific role of this author is articulated in the ‘author contributions’ section. All other funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.