Figure 2.

The level of the 5′ UTR ompA RBA in MC4100 cells grown exponentially with high (LB) or slow (Mops-acetate medium) growth rate. (A) Mobility-shift assay. S30 extracts (10 μg) were incubated with ³²P-labeled ompA transcript and analyzed, as described in Materials and Methods. Lane 1, the ompA transcript alone; lanes 2 and 3, the ompA transcript incubated with extract obtained from cells grown in LB and Mops-acetate medium, respectively. (B) Western blot analysis of the same extracts as in A tested with Hfq-specific antibodies, as described in Materials and Methods.