PhrA2 influences the gene expression levels of the TprA/PhrA system.

<p>qRT-PCR measurements of gene expression for target genes performed in strain PN4595-T23. Data was normalized to levels of 16S rRNA. The X-axis denotes test genes of TprA/PhrA system and treatment conditions. The Y-axis reflects the fold change in the treatment group relative to the no treatment control. Treatments correspond to: (i) PhrA2 C-terminal heptapeptide (VDLGLAD); (ii) PhrA C-terminal heptapeptide (LDVGKAD); or (iii) scrambled peptide (DAGVLDL). Error bars represent standard deviations for biological replicates (n = 3). (A) Target genes correspond to <i>tprA</i> regulator (gray bar), its cognate <i>phrA</i> peptide (white bar), and lantibiotic genes in the TprA regulon (<i>lanA</i>/dark bar; <i>lanM</i> stripped bar; and <i>lanT</i>/dotted bar). * Statistically significant difference in gene expression compared to scrambled peptide (<i>P</i>-value<0.05). (B) Target genes correspond to <i>tprA2</i> regulator (gray bar), its cognate <i>phrA2</i> peptide (white bar), and <i>lcpA</i> /dark bar. * Statistically significant difference in gene expression compared to scrambled peptide (<i>P</i>-value<0.01, ns = not significant).