Molecular mechanism of elongation factor 1A inhibition by a Legionella pneumophila glycosyltransferase

Ramon Hurtado-Guerrero, Tal Zusman, Shalini Pathak, Adel F. M. Ibrahim, Sharon Shepherd, Alan Prescott, Gil Segal, Daan M. F. van Aalten

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    22 Citations (Scopus)

    Abstract

    Legionnaires' disease is caused by a lethal colonization of alveolar macrophages with the Gram-negative bacterium Legionella pneumophila. LpGT (L. pneumophila glucosyltransferase: also known as Lgt1) has recently been identified as a virulence factor, shutting Clown protein synthesis in the human cell by specific glucosylation of EF1A (elongation factor 1A), using all Unknown mole of substrate recognition and a retaining mechanism for glycosyl transfer. We have determined the crystal Structure of LpGT in complex with Substrates, revealing a GT-A fold with two unusual protruding domains. Through structure-guided mutagenesis of LpGT, several residues essential for binding of the UDP-glucose-donor and EF1A-acceptor substrates were identified, which also affected L. pneumophila virulence as demonstrated by microinjection studies. Together, these results suggested that a positively charged EF1A loop binds to a negatively charged conserved groove oil the LpGT structure. and that two asparagine residues are essential for catalysis. Furthermore, we showed that two further L. pneumophila glycosyltransferases possessed the conserved UDP-glucose-binding sites and EF1A-binding grooves. and are. like LpGT, translocated into the macrophage through the Icm/Dot (intracellular multiplication/defect in organelle trafficking) system.

    Original languageEnglish
    Pages (from-to)281-292
    Number of pages12
    JournalBiochemical Journal
    Volume426
    DOIs
    Publication statusPublished - 15 Mar 2010

    Keywords

    • elongation factor 1A (EF1A)
    • glucosyl transferase
    • Legionella pneumophila
    • microinjection
    • site-directed mutagenesis
    • protein structure
    • LARGE CLOSTRIDIAL CYTOTOXINS
    • NUCLEOTIDE-EXCHANGE FACTOR
    • DIFFICILE TOXIN-B
    • HISTO-BLOOD GROUP
    • STRUCTURAL BASIS
    • CONFORMATIONAL-CHANGES
    • CRYSTAL-STRUCTURE
    • PROTEIN STRUCTURES
    • COXIELLA-BURNETII
    • HUMAN MACROPHAGES

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