Fig. 3.

Properties of a different fusion strain that has a linker between FliF and FliG. (a) Nucleotide and amino-acid sequences at the FliF–FliG junction. (b) Motility of the linker-fusion strain in soft agar. A tryptone soft-agar plate was inoculated with 3 μl of overnight cultures and incubated for 8 h at 32 °C. Following a short delay in the onset of motility, the fusion-linker strain migrates at >80% of the wild-type rate. (c) Anti-FliG immunoblots of whole-cell samples and cell fractions showing that native-sized FliG is not present at a significant level in the fusion-linker strain. w.c., whole cell; mem, membrane; cyto, cytosol; w.c. + FliG, whole cells with native-sized FliG expressed from a plasmid (pDB97, with no induction). (d) Rotation speeds of tethered cells of the FliF–FliG fusion-linker strain and of the wild type. Cells were tethered to coverslips by anti-flagellin antibody, and rotation speeds were determined by slow-speed video playback.