Cloning, expression, purification and preliminary X-ray diffraction studies of a novel AB 5toxin Academic Article uri icon


  • AB₅ toxins are key virulence factors found in a range of pathogenic bacteria. AB₅ toxins consist of two components: a pentameric B subunit that targets eukaryotic cells by binding to glycans located on the cell surface and a catalytic A subunit that disrupts host cellular function following internalization. To date, the A subunits of AB₅ toxins either have RNA-N-glycosidase, ADP-ribosyltransferase or serine protease activity. However, it has been suggested that a novel AB₅ toxin produced by clinical isolates of Escherichia coli and Citrobacter freundii has an A subunit with metalloproteinase activity. Here, the expression, purification and crystallization of this novel AB₅ toxin from E. coli (EcxAB) and the collection of X-ray data to 1.9 Å resolution are reported.


  • Ng, N
  • Littler, D
  • Le Nours, J
  • Paton, AW
  • Paton, JC
  • Rossjohn, J
  • Beddoe, T

publication date

  • 2013