title: Influence of impaired lipoprotein biogenesis on surface and exoproteome of Streptococcus pneumoniae.
abstract: Surface proteins are important for the fitness and virulence of the Gram-positive pathogen Streptococcus pneumoniae. They are crucial for interaction of the pathogen with its human host during infection. Therefore, the analysis of the pneumococcal surface proteome is an important task that requires powerful tools. In this study, two different methods, an optimized biotinylation approach and shaving with trypsin beads, were applied to study the pneumococcal surface proteome and to identify surface-exposed protein domains, respectively. The identification of nearly 95% of the predicted lipoproteins and 75% of the predicted sortase substrates reflects the high coverage of the two classical surface protein classes accomplished in this study. Furthermore, the biotinylation approach was applied to study the impact of an impaired lipoprotein maturation pathway on the cell envelope proteome and exoproteome. Loss of the lipoprotein diacylglyceryl transferase Lgt leads to striking changes in the lipoprotein distribution. Many lipoproteins disappear from the surface proteome and accumulate in the exoproteome. Further insights into lipoprotein processing in pneumococci are provided by immunoblot analyses of bacterial lysates and corresponding supernatant fractions. Taken together, the first comprehensive overview of the pneumococcal surface and exoproteome is presented, and a model for lipoprotein processing in S. pneumoniae is proposed.
authors.affiliation: Department Genetics of Microorganisms, Interfaculty Institute for Genetics and Functional Genomics, Ernst Moritz Arndt University of Greifswald , Friedrich-Ludwig-Jahn-Str. 15a, Greifswald D-17487, Germany.
authors.forename: Thomas
authors.initials: T
authors.lastname: Pribyl
authors.forename: Martin
authors.initials: M
authors.lastname: Moche
authors.forename: Annette
authors.initials: A
authors.lastname: Dreisbach
authors.forename: Jetta J E
authors.initials: JJ
authors.lastname: Bijlsma
authors.forename: Malek
authors.initials: M
authors.lastname: Saleh
authors.forename: Mohammed R
authors.initials: MR
authors.lastname: Abdullah
authors.forename: Michael
authors.initials: M
authors.lastname: Hecker
authors.forename: Jan Maarten
authors.initials: JM
authors.lastname: van Dijl
authors.forename: Dörte
authors.initials: D
authors.lastname: Becher
authors.forename: Sven
authors.initials: S
authors.lastname: Hammerschmidt
mesh_terms: D001426:Bacterial Proteins / Q000096:biosynthesis* / Q000378:metabolism; D001483:Base Sequence; D001710:Biotin / Q000378:metabolism; D017931:DNA Primers; D004591:Electrophoresis, Polyacrylamide Gel; D008074:Lipoproteins / Q000096:biosynthesis* / Q000378:metabolism; D016133:Polymerase Chain Reaction; D020543:Proteome; D013296:Streptococcus pneumoniae / Q000378:metabolism*; D013347:Subcellular Fractions / Q000378:metabolism; D014357:Trypsin / Q000378:metabolism
chemical_list: D001426:Bacterial Proteins; D017931:DNA Primers; D008074:Lipoproteins; D020543:Proteome; D001710:Biotin; D014357:Trypsin