Fig. (4) Northern blots; the total RNA were probed with a DNA fragment of lacZ ⁺ (A), or clpQ⁺ (B). The HY20001 (the wild-type), HY20005 (rpoH), HY20006 (ropS), and HY20007 (rpoH rpoS) mutants, each carrying λclpQ⁺::lacZ⁺, were hosts for the RNA isolation. Each lane contains 3 µg RNA for the analysis. The ethidium-bromide stained 16S rRNA was used for normalization of the gel loading.