Fig 5.

Characterization of a point mutation of SltF. (A) Swimming assay on 0.25% soft agar plates supplemented with 100 μM sodium propionate. Portions (3 μl) of the strains WS8, SltF1, SltF1/sltF, SltF1/sltFE57A were inoculated onto soft agar plates, followed by incubation as described in Materials and Methods. The various versions of sltF were cloned in pRK415 (for details, see Materials and Methods). (B) Flagellin (FliC) secretion analyzed by Western blot analysis. The same strains were grown and fractionated in either pellet (P) or supernatant (SN) and then probed with specific gamma globulins at a 1:10,000 dilution. (C) Coimmunoprecipitation assay. Anti-SltF gamma globulins were coupled to protein A-Sepharose beads, followed by incubation with the indicated proteins. These were detected using HisProbe-HRP at a 1:10,000 dilution as indicated in Materials and Methods.