Analysis of transcription of the acid-responsive genes hp0119 (A.) and hp1432 (B.) in <i>H. pylori</i> strains expressing ArsS proteins with individual histidine to glutamine mutations in the input domain.

<p>A. Primer extension analysis using the radiolabelled oligonucleotide HP119PE was performed on equal amounts of RNA extracted from the <i>H. pylori</i> strains 26695 (lane 1), 26695/arsS-H0 (lane 2), 26695/arsS-H35Q (lane 3), 26695/arsS-H44Q (lane 4), 26695/arsS-H90Q (lane 5), 26695/arsS-H93Q (lane 6), 26695/arsS-H94Q (lane 7), 26695/arsS-H118Q (lane 8), 26695/arsS-H126Q (lane 9) and 26695/arsS::km (lane 10) which were exposed to pH 5.0 for one hour. The hp0119-specific cDNA is indicated by a black arrow on the right. The sequencing ladder (lanes T, G, C, A) was obtained by annealing oligonucleotide HP119PE to plasmid pSL-119PE2 <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0006930#pone.0006930-Dietz1" target="_blank">[39]</a>. The gray arrow indicates the position of a cDNA band representing a non-specific primer elongation product whose unchanged intensity indicates the presence of equal amounts of RNA in the different samples. The sequence of the -10 element of the hp0119 promoter is shown on the left. B. Primer extension analysis using the radiolabelled oligonucleotide HP1432PE was performed on equal amounts of RNA extracted from the <i>H. pylori</i> strains 26695 (lane 9), 26695/arsS-H0 (lane 1), 26695/arsS-H35Q (lane 2), 26695/arsS-H44Q (lane 3), 26695/arsS-H90Q (lane 4), 26695/arsS-H93Q (lane 5), 26695/arsS-H94Q (lane 6), 26695/arsS-H118Q (lane 7), 26695/arsS-H126Q (lane 8) and 26695/arsS::km (lane 10) which were exposed to pH 5.0 for one hour. The hp1432-specific cDNA is indicated by a black arrow on the right.