Evaluation of strength of <i>sodC</i> promoters from <i>B. abortus</i>, <i>B. neotomae</i>, <i>B. suis</i> biovars 2 (strain Thomsen) and 4 (strain 40).

<p>A) Nucleotide sequence features of the promoter-containing 5′ flanking region of <i>B. abortus sodC</i> gene as cloned in pBaSODpro/lacZ. The <i>sodC</i> start codon, ribosomal binding site (RBS), and 5′ ends of cDNA are indicated in bold. The asterisk indicates the site of nucleotide insertion polymorphism with <i>B. neotoame</i> and <i>B. suis</i> biovars. The two potential −10 sequences are boxed (see <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0014112#s4" target="_blank">Discussion</a>). B) Expression levels of β-galactosidase in late log phase cultures of <i>B. neotomae</i> cultures harboring plasmids with <i>lacZ</i> gene cloned under the control of <i>sodC</i> promoters obtained from the indicated <i>Brucella</i> spp. For each promoter construct, the assays were performed using 3 separate colony cultures. Results are shown as the mean ± standard deviation of Miller units. Means with the same number of asterisks were not significantly different from each other (<i>P</i>>0.05). There were significant differences between means with different number of asterisks (<i>P</i><0.001).</p>