title: Cloning, expression, purification and preliminary X-ray diffraction studies of a novel AB₅ toxin.
abstract: 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.
authors.affiliation: Department of Biochemistry and Molecular Biology, Monash University, Clayton, Victoria, Australia.
authors.forename: Natasha
authors.initials: N
authors.lastname: Ng
authors.forename: Dene
authors.initials: D
authors.lastname: Littler
authors.forename: Jérôme
authors.initials: J
authors.lastname: Le Nours
authors.forename: Adrienne W
authors.initials: AW
authors.lastname: Paton
authors.forename: James C
authors.initials: JC
authors.lastname: Paton
authors.forename: Jamie
authors.initials: J
authors.lastname: Rossjohn
authors.forename: Travis
authors.initials: T
authors.lastname: Beddoe
mesh_terms: D001427:Bacterial Toxins / Q000096:biosynthesis / Q000737:chemistry / Q000235:genetics*; D003001:Cloning, Molecular / Q000379:methods; D029968:Escherichia coli Proteins / Q000096:biosynthesis / Q000737:chemistry / Q000235:genetics*; D015964:Gene Expression Regulation, Bacterial; D021122:Protein Subunits / Q000737:chemistry / Q000235:genetics; D014961:X-Ray Diffraction
chemical_list: D001427:Bacterial Toxins; D029968:Escherichia coli Proteins; D021122:Protein Subunits
keywords: AB5 toxins; Escherichia coli; co-expression; proteases
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