Delineation of the pH-Responsive Regulon Controlled by the Helicobacter pylori ArsRS Two-Component System.

encounters a wide range of pH within the human stomach. In a comparison of cultured under neutral or acidic conditions, about 15% of genes are differentially expressed, and corresponding changes are detectable for many of the encoded proteins. The ArsRS two-component system (TCS), comprised of the sensor kinase ArsS and its cognate response regulator ArsR, has an important role in mediating pH-responsive changes in gene expression.