title: Reconstitution of membrane protein complexes involved in pneumococcal septal cell wall assembly.
abstract: The synthesis of peptidoglycan, the major component of the bacterial cell wall, is essential to cell survival, yet its mechanism remains poorly understood. In the present work, we have isolated several membrane protein complexes consisting of the late division proteins of Streptococcus pneumoniae: DivIB, DivIC, FtsL, PBP2x and FtsW, or subsets thereof. We have co-expressed membrane proteins from S. pneumoniae in Escherichia coli. By combining two successive affinity chromatography steps, we obtained membrane protein complexes with a very good purity. These complexes are functional, as indicated by the retained activity of PBP2x to bind a fluorescent derivative of penicillin and to hydrolyze the substrate analogue S2d. Moreover, we have evidenced the stabilizing role of protein-protein interactions within each complex. This work paves the way for a complete reconstitution of peptidoglycan synthesis in vitro, which will be critical to the elucidation of its intricate regulation mechanisms.
authors.affiliation: Institut de Biologie Structurale, Université Grenoble Alpes, Grenoble, France ; Institut de Biologie Structurale, Direction des Sciences du Vivant, Commissariat à l'energie atomique et aux Energies Alternatives, Grenoble, France ; Institut de Biologie Structurale, Centre National de la Recherche Scientifique, Grenoble, France.
authors.forename: Marjolaine
authors.initials: M
authors.lastname: Noirclerc-Savoye
authors.forename: Violaine
authors.initials: V
authors.lastname: Lantez
authors.forename: Luca
authors.initials: L
authors.lastname: Signor
authors.forename: Jules
authors.initials: J
authors.lastname: Philippe
authors.forename: Thierry
authors.initials: T
authors.lastname: Vernet
authors.forename: André
authors.initials: A
authors.lastname: Zapun
mesh_terms: D001426:Bacterial Proteins / Q000235:genetics / Q000302:isolation & purification / Q000378:metabolism*; D002455:Cell Division; D002473:Cell Wall / Q000378:metabolism*; D006868:Hydrolysis; D007700:Kinetics; D008565:Membrane Proteins / Q000235:genetics / Q000302:isolation & purification / Q000378:metabolism*; D059748:Proteolysis; D011994:Recombinant Proteins / Q000235:genetics / Q000302:isolation & purification / Q000378:metabolism; D013296:Streptococcus pneumoniae / Q000235:genetics / Q000378:metabolism*
chemical_list: D001426:Bacterial Proteins; D008565:Membrane Proteins; D011994:Recombinant Proteins