Mapping of <i>cag</i> promoters.

<p><b>A</b>. Genomic organization of the <i>cag</i> pathogenicity island in the <i>H. pylori</i> G27 strain. (1) Transcriptional units mapped in this study; black: plus strand; grey: minus strand. (2) Annotated <i>cag</i> genes and ORFs; white block arrow: ORF encoding effector toxin CagA; dark grey block arrows: ORFs encoding structural T4SS components; light grey block arrows: ORFs encoding components with ancillary or unknown function. (3) Alphabetic classification of <i>cag</i> genes. (4) Numeric classification of <i>cag</i> genes. (5) Annotation of <i>cag</i> genes in reference strain 26695. (6) Transcriptional start sites mapped in <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0098416#pone.0098416-Sharma1" target="_blank">[20]</a>. (7) Transcriptional units identified in <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0098416#pone.0098416-Spohn1" target="_blank">[17]</a>, <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0098416#pone.0098416-Joyce1" target="_blank">[33]</a>. (8) Transcriptional units identified by unbiased promoter-trapping experiments in <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0098416#pone.0098416-Ta1" target="_blank">[30] </a><b>B</b>. Summary of relevant features within the nucleotide sequences of the P<i>cag</i> promoters mapped in this study. The TSSs (+1) are boxed in black boxes and showed in boldface. Sequences corresponding to -10 regions, the extended TGn elements and recognizable -35 region are enlightened in grey boxes. <b>C</b>. Comparison of the transcript levels at the P<i>cag</i> promoters fused with <i>lux</i> reporter genes. mRNA levels of the P<i>cag</i>-<i>lux</i> constructs were assayed by primer extension analysis using the oligonucleotide VSluxC1 and quantified with a phospoimager. The mean values from three independent experiments are reported as arbitrary units of ³²P counts.