2WZF

Molecular Mechanism of Elongation Factor 1A Inhibition by a Legionella Pneumophila Glycosyltransferase.

(2010) Biochem J 426: 281

• PubMed: 20030628 Search on PubMedSearch on PubMed Central
• DOI: https://doi.org/10.1042/BJ20091351
• Primary Citation of Related Structures:  
  2WZF, 2WZG


• PubMed 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 down protein synthesis in the human cell by specific glucosylation of EF1A (elongation factor 1A), using an unknown mode 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 on 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.

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Organizational Affiliation: 

Division of Molecular Microbiology, College of Life Sciences, University of Dundee, Dundee DD1 5EH, Scotland, UK. [email protected]