Localization of the ComEA protein in naturally competent <i>V. cholerae</i> cells.

<p>(A) Expression and distribution of ComEA-mCherry (upper row) or signal sequence[ComEA] (amino acids 1–25)-mCherry fusion proteins (lower row) within competent <i>V. cholerae</i> cells. Fluorescent signals for mCherry or DAPI-stained genomic DNA were visualized and compared with each other (merge) and the corresponding phase contrast image (Ph). (B) Representative fluorescence loss in photobleaching (FLIP) experiment to demonstrate the degree of mobility of ComEA-mCherry in live bacteria. Bleaching of the region-of-interest (ROI) 1 (indicated as 1 in the images on the right) was initiated after the acquisition of 20 frames and repeated after every frame. The fluorescence intensities of ROIs 1–3 were measured for a total of 20 sec and normalized to the average fluorescence intensity of the first 10 frames. The moving averages (period n = 5) are indicated with black lines. The average fluorescence intensity projections before (pre-bleach) and after bleaching (post-bleach) are shown on the right. Scale bars, 2 µm.