FIG 6.
Filament morphology of wild-type and flagellin mutant suppressors that have chromosomal copies of FlaACys or FlaBCys. Flagella are visualized with fluorescence microscopy of cells labeled with Alexa Fluor maleimide dye linkage to cysteine residues in specific flagellins. The FlaCys residues were introduced into the flaA (A) or flaB (B to D) by allelic exchange of the resident gene with wild-type C58 (A and B), the ΔflaACD fms-6 mutant (C), and the ΔflaA fms-13 mutant. The scale bar of 10 μm applies to all images. Flagellar filaments with cysteine labeling of FlaC and FlaD could not be visualized, likely due to their low abundance. SD* refers to the mutated Shine-Dalgarno sequence in the suppressor mutant. Images were collected with a Nikon Ti microscope.