Fig 8.

One PilA paralog is sufficient to promote pilus synthesis. Electron micrograph of ΔflgA[1-2] transformed with pTA963 (+ control) and ΔpilA[1-6]ΔflgA[1-2] transformed with pTA963 (− control) or pTA963 expressing one of the six pilin genes (pilA[1-6]). Pili are observable when at least one pilin gene is expressed (arrows). Similar numbers of pili were seen on the surfaces of PilA[1-6] mutants. Cells were fixed in 2% glutaraldehyde and 1% paraformaldehyde and stained with 1% uranyl formate. Bars, 200 nm.