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Composition, structure and function of the Helicobacter pylori cag pathogenicity island encoded type IV secretion system

    Steffen Backert

    *Author for correspondence:

    E-mail Address: Steffen.Backert@fau.de

    Department of Biology, Division of Microbiology, Friedrich Alexander University Erlangen-Nuremberg, Staudtstr. 5, D-91058 Erlangen, Germany

    ,
    Nicole Tegtmeyer

    Department of Biology, Division of Microbiology, Friedrich Alexander University Erlangen-Nuremberg, Staudtstr. 5, D-91058 Erlangen, Germany

    &
    Wolfgang Fischer

    Max von Pettenkofer-Institute for Hygiene & Medical Microbiology, Ludwig Maximilians-University, D-80336 Munich, Germany

    Published Online:https://doi.org/10.2217/fmb.15.32

    ABSTRACT 

    Many Gram-negative pathogens harbor type IV secretion systems (T4SS) that translocate bacterial virulence factors into host cells to hijack cellular processes. The pathology of the gastric pathogen Helicobacter pylori strongly depends on a T4SS encoded by the cag pathogenicity island. This T4SS forms a needle-like pilus, and its assembly is accomplished by multiple protein–protein interactions and various pilus-associated factors that bind to integrins followed by delivery of the CagA oncoprotein into gastric epithelial cells. Recent studies revealed the crystal structures of six T4SS proteins and pilus formation is modulated by iron and zinc availability. All these T4SS interactions are crucial for deregulating host signaling events and disease progression. New developments in T4SS functions and their importance for pathogenesis are discussed.

    Papers of special note have been highlighted as: • of interest; •• of considerable interest

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