FIG. 1.
Schematic representation of the strategy used for mutant construction. (a) Structure of the vacA gene in H. pylori CCUG17874. The sequence of the 46-aa hydrophilic loop containing the 8-aa repeat is shown. (b) Structure of the H. pylori VacA::Kmr strain in which the region between restriction sites EcoNI (En) and BsaBI (Bs) has been replaced with a kanamycin resistance cassette. (c) Structure of the delivery plasmid containing mutated vacA genes. Dotted lines indicate the region of recombination to replace the vacA gene. H, HindIII, B, BamHI.