Cell surface filaments of the gliding bacterium Flavobacterium johnsoniae revealed by cryo-electron tomography

Flavobacterium johnsoniae cells glide rapidly over surfaces by an as-yet-unknown mechanism. Using cryoelectron tomography, we show that wild-type cells display tufts of -5-nm-wide cell surface filaments that appear to be anchored to the inner surface of the outer membrane. These filaments are absent in cells of a nonmotile gldF mutant but are restored upon expression of plasmid-encoded GldF, a component of a putative ATP-binding cassette transporter.