FIGURE 7.

The sub-polar localization of RNases J1 and J2 is lost upon inhibition of RNA synthesis by rifampicin. Fluorescence microscopy of strains (A) GP1694 (Pxyl-rnjA-gfp) and (B) GP1695 (Pxyl-rnjB-gfp). Bacteria were grown in LB medium at 37°C to mid-exponential phase, when rifampicin or methanol were added to the cultures as described above. The expression of RNase J1-GFP and RNase J2-GFP was induced by addition of 0.1% xylose to the culture medium. The nucleoid was stained by DAPI as described in the Material and Methods section. The sub-polar localization of both RNases J1 and J2 is lost as the RNA synthesis is inhibited and the proteins appear evenly distributed in the cytoplasm. Upon addition of rifampicin the nucleoid, stained by DAPI, spreads occupying the majority of the cell volume. Scale bar, 2 μm. PC, phase contrast.