FIGURE 2.
DsrADII competes with full-length DsrA for binding to Hfq. 5′-end-labeled DsrA was incubated with increasing concentrations of DsrADI, DsrADII, and DsrADIII at 25°C for 5 min, followed by the addition of Hfq and an incubation at 25°C for 5 min. Samples were separated on an 8% native polyacrylamide gel in 1× TBE. (A) DsrADI, (B) DsrADII, and (C) DsrADIII were incubated with full-length 5′-end-labeled DsrA. Samples were incubated without (−) or with (+) 3 μM Hfq. (D) 5′-end-labeled full-length DsrA (+), DsrADI (•), DsrADII (▴), or DsrADIII (▪) were incubated at 25°C for 10 min with the indicated amounts of purified Hfq. The percent of unbound RNA was determined using a phosphorimager (see Materials and Methods) and plotted against Hfq concentration. Only full-length DsrA and DsrADII bound to Hfq.