title: Mutational analysis of the Helicobacter pylori vacuolating toxin amino terminus: identification of amino acids essential for cellular vacuolation.
abstract: The functional importance of the amino terminus of the Helicobacter pylori vacuolating cytotoxin (VacA) was investigated by analyzing the relative levels of vacuolation of HeLa cells transfected with plasmids encoding wild-type and mutant forms of the toxin. Notably, VacA's intracellular activity was found to be sensitive to small truncations and internal deletions at the toxin's amino terminus. Moreover, alanine-scanning mutagenesis revealed the first VacA point mutations (at proline 9 or glycine 14) that completely abolish the toxin's intracellular activity.
authors.affiliation: Department of Biology and Biochemistry, University of Houston, Houston, Texas 77204-5513, USA.
authors.forename: D
authors.initials: D
authors.lastname: Ye
authors.forename: S R
authors.initials: SR
authors.lastname: Blanke
mesh_terms: D001426:Bacterial Proteins / Q000737:chemistry / Q000235:genetics* / Q000502:physiology; D001427:Bacterial Toxins / Q000737:chemistry / Q000235:genetics*; D005816:Genetic Complementation Test; D006367:HeLa Cells; D016480:Helicobacter pylori / Q000235:genetics* / Q000472:pathogenicity* / Q000502:physiology; D006801:Humans; D009154:Mutation; D017354:Point Mutation; D017384:Sequence Deletion; D014617:Vacuoles / Q000382:microbiology; D014774:Virulence / Q000235:genetics / Q000502:physiology
chemical_list: D001426:Bacterial Proteins; D001427:Bacterial Toxins; C074689:VacA protein, Helicobacter pylori