FIGURE 1.

Western blot analysis of Hfq in the mutants obtained from the combined genetic selection/screen. The wild-type strain MG1193 (Hfq WT) and the hfq point mutants obtained from the combined genetic selection and screen, NRD304 (Hfq G4G), NRD307 (Hfq Q8R), NRD309 (Hfq F42L), NRD310 (D40N), NRD314 (Y55C), NRD317 (R16C), NRD323 (D9A), and NRD325 (H57R), were grown overnight in glucose minimal M63 medium. A sample was removed from each culture and processed for Western blotting with anti-Hfq polyclonal antibody as described in Materials and Methods. An equal amount of protein based on the cell density of each culture was applied to the polyacrylamide gel. A representative Western blot is shown in A. The intensity of the bands on the Western blots was quantified using the Multi Gauge software; intensity of Hfq from the wild-type strain was set to 100%, and the signal from all other strains was normalized to this sample. The results shown in B represent the mean of two experiments.