A bearing that supports the driving shaft of the flagellar motor,
which is a motor organ of bacteria.
A bacterium moves around by rotating its flagellum with flagellar
motor that is driven chemically by hydrogen ions or sodium ions. A ring structure is known to be
supporting the driving shaft of the flagellar motor. Former studies suggested that the bearing is
lubricated by ions, although most part of the mechanism is left unknown. The ring, which measures
about 30 nm in diameter, is thought to bear the driving shaft of the flagellar motor with several
thousands revolutions per second.