English (United Kingdom)

https://curated-unify.zendy.io/wp-json/zendy-region/v1/featured_content/oa?rat=en

https://curated-unify.zendy.io/wp-json/zendy-region/v1/highlighted_journal/

Global: Zendy Plus annual

Presents the access of premium content as premium feature

Premium Content

Presents the keyphrase highlighting as premium feature

Keyphrase Highlighting

Presents the summarisation as premium feature

Summarisation

Insights

Presents the pdf analysis as premium feature

PDF Analysis

Presents the zaia usage as premium feature

ZAIA

Global: Zendy Tools annual

Global: Zendy Free Plan

Global: Zendy Tools monthly

Global: Zendy Plus monthly

Research on Helicobacter pylori has been hindered by the lack of useful genetic tools. Using the sacB gene of Bacillus subtilis, we developed a sucrose-based counterselection system that allows introduction of unmarked mutations in H. pylori. A kan-sacB cassette, consisting of the sacB gene expressed from the H. pylori flagellin promoter and the kanamycin resistance module, was introduced by homologous recombination into a target H. pylori gene. The resultant strains were sucrose sensitive and kanamycin resistant. Following transformation with a mutated allele, growth in sucrose-containing medium allowed the selection of strains that had lost the kan-sacB module and had integrated the unmarked allele. We have used this cassette to perform a site-directed modification of two histidine residues encoded by the vacA gene in a two-step procedure. This system should prove useful in the site-directed mutagenesis of H. pylori genes.

Introduction of unmarked mutations in the Helicobacter pylori vacA gene with a sucrose sensitivity marker