One of the proteins that forms a switch complex that is proposed to be located at the base of the basal body. This complex interacts with chemotaxis proteins (such as CheY) in addition to contacting components of the motor that determine the direction of flagellar rotation. Required for flagellum synthesis and motility. In H.pylori four flagellar switch proteins are encoded, FliG, FliM, FliN and FliY. Nonflagellate. Forms dense colonies without swarming in contrast to the wild-type which forms diffuse colonies with large, swarming halos. Expression of flagellins FlaA and FlaB and the hook protein FlgE greatly reduced. Belongs to the FliG family.