title: Structural studies of the transpeptidase domain of PBP1a from Streptococcus pneumoniae.
abstract: 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.
authors.affiliation: Laboratoire de Cristallographie Macromoléculaire, Institut de Biologie Structurale Jean-Pierre Ebel (CEA/CNRS/UJF), 41 Rue Jules Horowitz, 38027 Grenoble, France.
authors.forename: Viviana
authors.initials: V
authors.lastname: Job
authors.forename: Anne Marie
authors.initials: AM
authors.lastname: Di Guilmi
authors.forename: Lydie
authors.initials: L
authors.lastname: Martin
authors.forename: Thierry
authors.initials: T
authors.lastname: Vernet
authors.forename: Otto
authors.initials: O
authors.lastname: Dideberg
authors.forename: Andréa
authors.initials: A
authors.lastname: Dessen
mesh_terms: D001426:Bacterial Proteins / Q000096:biosynthesis / Q000737:chemistry* / Q000302:isolation & purification; D002850:Chromatography, Gel; D002852:Chromatography, Ion Exchange; D005615:Freezing; D008970:Molecular Weight; D010458:Peptidyl Transferases / Q000096:biosynthesis / Q000737:chemistry* / Q000302:isolation & purification; D013296:Streptococcus pneumoniae / Q000201:enzymology*; D014961:X-Ray Diffraction
chemical_list: D001426:Bacterial Proteins; C480727:PBP1a protein, Streptococcus pneumoniae; D010458:Peptidyl Transferases