NtrX phosphorylation is also triggered by acidic pH in <i>Brucella abortus</i>.

<p>Phosphoprotein affinity gel electrophoresis followed by Western blot of samples of the <i>B</i>. <i>abortus</i> BA-NtrX_myc strain grown in minimal medium until logarithmic phase (‘MM log’), resuspended in fresh MM with its pH adjusted to different values and incubated for 30 min. As controls, samples of cultures at log and stationary phases were analyzed (‘MM log’ and ‘MM sta’, respectively). The phosphorylated and non-phosphorylated forms of NtrX are indicated on the left of the gels. Two independent experiments were performed and the bands were quantified to calculate mean ± SD, which were plotted in a graph presented on the right of the figure.