Structural Studies of the Transpeptidase Domain of PBP1a From Streptococcus Pneumoniae

Acta Crystallogr D Biol Crystallogr. 2003 Jun;59(Pt 6):1067-9. doi: 10.1107/s0907444903006954. Epub 2003 May 23.


The synthesis of the bacterial cell wall requires enzymes which are localized both in the cytoplasm and in the periplasm. Penicillin-binding proteins (PBPs) catalyze the last, crucial steps in peptidoglycan biosynthesis and several of them are essential for bacterial survival. High-molecular-mass PBPs can be bifunctional (class A) or monofunctional (class B) and to date no structural information on any class A PBP is available. To initiate the determination of the three-dimensional structure of a class A PBP, crystals of the transpeptidase domain of PBP1a from Streptococcus pneumoniae were prepared by limited proteolysis of the full-length molecule and purification by anion-exchange chromatography and gel filtration. The samples crystallize in space group C222(1), contain one molecule per asymmetric unit and diffract X-rays to 2.7 A. Selenomethionine-labelled crystals have been prepared and structure solution is under way.

MeSH terms

  • Bacterial Proteins / biosynthesis
  • Bacterial Proteins / chemistry*
  • Bacterial Proteins / isolation & purification
  • Chromatography, Gel
  • Chromatography, Ion Exchange
  • Freezing
  • Molecular Weight
  • Peptidyl Transferases / biosynthesis
  • Peptidyl Transferases / chemistry*
  • Peptidyl Transferases / isolation & purification
  • Streptococcus pneumoniae / enzymology*
  • X-Ray Diffraction


  • Bacterial Proteins
  • PBP1a protein, Streptococcus pneumoniae
  • Peptidyl Transferases