FIGURE 1.

A, schematic diagram of trp leader RNA, showing structural features and location of primary RNase J1 cleavage site. B, Northern blot analysis of trp leader RNA in wild-type and RNase J1 conditional mutant strains grown in the presence of 1 mm IPTG. Time after rifampicin addition (min) is indicated above each lane. Migration of the 136-nt marker (lane M) is indicated at left. Semi-log plot of % RNA remaining versus time is shown at right. Open triangles, wild type; closed squares, RNase J1 mutant.