GLORIA

GEOMAR Library Ocean Research Information Access

X

Your email was sent successfully. Check your inbox.

An error occurred while sending the email. Please try again.

Proceed reservation?

Export
Filter
  • American Society for Microbiology  (4)
  • Fischer, Wolfgang  (4)
Material
Publisher
  • American Society for Microbiology  (4)
Person/Organisation
Language
Years
Subjects(RVK)
  • 1
    Online Resource
    Online Resource
    Functional and Topological Characterization of Novel Components of the comB DNA Transformation Competence System in Helicobacter pylori
    American Society for Microbiology ; 2006
    In:  Journal of Bacteriology Vol. 188, No. 3 ( 2006-02), p. 882-893
    Details
    In: Journal of Bacteriology, American Society for Microbiology, Vol. 188, No. 3 ( 2006-02), p. 882-893
    Abstract: Helicobacter pylori is one of the most diverse bacterial species known. A rational basis for this genetic variation may be provided by its natural competence for genetic transformation and high-frequency recombination. Many bacterial competence systems have homology with proteins that are involved in the assembly of type IV pili and type II secretion systems. In H. pylori , DNA uptake relies on a transport system related to type IV secretion systems (T4SS) designated the comB system. The prototype of a T4SS in Agrobacterium tumefaciens consists of 11 VirB proteins and VirD4, which form the core unit necessary for the delivery of single proteins or large nucleoprotein complexes into target cells. In the past we identified proteins ComB4 and ComB7 through ComB10 as being involved in the process of DNA uptake in H. pylori . In this study we identified and functionally characterized further (T4SS-homologous) components of the comB transformation competence system. By combining computer prediction modeling, experimental topology determination, generation of knockout strains, and genetic complementation studies we identified ComB2, ComB3, and ComB6 as essential components of the transformation apparatus, structurally and functionally homologous to VirB2, VirB3, and VirB6, respectively. comB2 , comB3 , and comB4 are organized as a separate operon. Thus, for the H. pylori comB system, all T4SS core components have been identified except for homologues to VirB1, VirD4, VirB5, and VirB11.
    Type of Medium: Online Resource
    ISSN: 0021-9193 , 1098-5530
    URL: Article
    DOI: 10.1128/JB.188.3.882-893.2006
    Language: English
    Publisher: American Society for Microbiology
    Publication Date: 2006
    detail.hit.zdb_id: 1481988-0
    SSG: 12
    Location Call Number Limitation Availability
    BibTip Others were also interested in ...
    Online Resource
  • 2
    Online Resource
    Online Resource
    Outer Membrane Targeting of Passenger Proteins by the Vacuolating Cytotoxin Autotransporter of Helicobacter pylori
    American Society for Microbiology ; 2001
    In:  Infection and Immunity Vol. 69, No. 11 ( 2001-11), p. 6769-6775
    Details
    In: Infection and Immunity, American Society for Microbiology, Vol. 69, No. 11 ( 2001-11), p. 6769-6775
    Abstract: Helicobacter pylori produces a number of proteins associated with the outer membrane, including adhesins and the vacuolating cytotoxin. These proteins are supposed to integrate into the outer membrane by β-barrel structures, characteristic of the family of autotransporter proteins. By using the SOMPES (shuttle vector-based outer membrane protein expression) system for outer membrane protein production, we were able to functionally express in H. pylori the cholera toxin B subunit genetically fused to the C-terminal VacA domain. We demonstrate that the fusion protein is translocated to the H. pylori outer membrane and that the CtxB domain is exposed on the H. pylori surface. Thus, we provide the first experimental evidence that the C-terminal β-domain of VacA can transport a foreign passenger protein to the H. pylori surface and hence acts as a functional autotransporter.
    Type of Medium: Online Resource
    ISSN: 0019-9567 , 1098-5522
    URL: Article
    DOI: 10.1128/IAI.69.11.6769-6775.2001
    RVK:
    XA 10000
    Language: English
    Publisher: American Society for Microbiology
    Publication Date: 2001
    detail.hit.zdb_id: 1483247-1
    Location Call Number Limitation Availability
    BibTip Others were also interested in ...
    Online Resource
  • 3
    Online Resource
    Online Resource
    The RecA Protein of Helicobacter pylori Requires a Posttranslational Modification for Full Activity
    American Society for Microbiology ; 2004
    In:  Journal of Bacteriology Vol. 186, No. 3 ( 2004-02), p. 777-784
    Details
    In: Journal of Bacteriology, American Society for Microbiology, Vol. 186, No. 3 ( 2004-02), p. 777-784
    Abstract: The RecA protein is a central component of the homologous recombination machinery and of the SOS system in most bacteria. In performing these functions, it is involved in DNA repair processes and plays an important role in natural transformation competence. This may be especially important in Helicobacter pylori , where an unusually high degree of microdiversity among strains is generated by homologous recombination. We have suggested previously that the H. pylori RecA protein is subject to posttranslational modifications that result in a slight shift in its electrophoretic mobility. Here we show that at least two genes downstream of recA are involved in this modification and that this process is dependent on genes involved in glycosylation and lipopolysaccharide biosynthesis. Site-directed mutagenesis of a putative glycosylation site results in production of an unmodified RecA protein. This posttranslational modification is not involved in membrane targeting or cell division functions but is necessary for the full function of RecA in DNA repair. Thus, it might be an adaptation to the specific requirements of H. pylori in its natural environment.
    Type of Medium: Online Resource
    ISSN: 0021-9193 , 1098-5530
    URL: Article
    DOI: 10.1128/JB.186.3.777-784.2004
    Language: English
    Publisher: American Society for Microbiology
    Publication Date: 2004
    detail.hit.zdb_id: 1481988-0
    SSG: 12
    Location Call Number Limitation Availability
    BibTip Others were also interested in ...
    Online Resource
  • 4
    Online Resource
    Online Resource
    Protein Subassemblies of the Helicobacter pylori Cag Type IV Secretion System Revealed by Localization and Interaction Studies
    American Society for Microbiology ; 2008
    In:  Journal of Bacteriology Vol. 190, No. 6 ( 2008-03-15), p. 2161-2171
    Details
    In: Journal of Bacteriology, American Society for Microbiology, Vol. 190, No. 6 ( 2008-03-15), p. 2161-2171
    Abstract: Type IV secretion systems are possibly the most versatile protein transport systems in gram-negative bacteria, with substrates ranging from small proteins to large nucleoprotein complexes. In many cases, such as the cag pathogenicity island of Helicobacter pylori , genes encoding components of a type IV secretion system have been identified due to their sequence similarities to prototypical systems such as the VirB system of Agrobacterium tumefaciens . The Cag type IV secretion system contains at least 14 essential apparatus components and several substrate translocation and auxiliary factors, but the functions of most components cannot be inferred from their sequences due to the lack of similarities. In this study, we have performed a comprehensive sequence analysis of all essential or auxiliary Cag components, and we have used antisera raised against a subset of components to determine their subcellular localization. The results suggest that the Cag system contains functional analogues to all VirB components except VirB5. Moreover, we have characterized mutual stabilization effects and performed a comprehensive yeast two-hybrid screening for potential protein-protein interactions. Immunoprecipitation studies resulted in identification of a secretion apparatus subassembly at the outer membrane. Combining these data, we provide a first low-resolution model of the Cag type IV secretion apparatus.
    Type of Medium: Online Resource
    ISSN: 0021-9193 , 1098-5530
    URL: Article
    DOI: 10.1128/JB.01341-07
    Language: English
    Publisher: American Society for Microbiology
    Publication Date: 2008
    detail.hit.zdb_id: 1481988-0
    SSG: 12
    Location Call Number Limitation Availability
    BibTip Others were also interested in ...
    Online Resource
Close ⊗
This website uses cookies and the analysis tool Matomo. More information can be found here...