The M ring may be actively involved in energy transduction (By similarity). The flagellum is required to cause a persistent disease in a murine model of infection. The basal body constitutes a major portion of the flagellar organelle and consists of five rings (E,L,P,S, and M) mounted on a central rod. The M ring is integral to the inner membrane of the cell and may be connected to the flagellar rod via the S ring. The S (supramembrane ring) lies just distal to the M ring. The L and P rings lie in the outer membrane and the periplasmic space, respectively (By similarity). Transiently expressed during the early exponential phase. A fliF mutant is attenuated in a murine model of infection. As the infection progresses, the number of cfu per spleen from mice infected with the mutant is significantly lower than the number from mice infected with the wild-type. Induced at 24 and 48 hours post infection in HeLa cells. Belongs to the FliF family. Despite the presence of a stop codon in position 243 in the fliF gene and in position 127 in the flhA gene, it has been shown that B.melitensis is able to express genes corresponding to the M ring, the hook and the filament of the flagellar apparatus in the early log phase of growth in 2YT broth. Under these conditions, a polar and sheathed flagellar structure is visible by transmission electron microscopy. Truncated C-terminus.