The FliX protein is possibly a transient component of the flagellum that is required for the assembly process. FliX may contribute to the targeting or assembly of the P- and L-ring protein monomers at the cell pole. The family carries a potential N-terminal signal sequence and at least one transmembrane domain indicating that it might function either in or in association with the cell membrane [1].

1: A membrane-associated protein, FliX, is required for an early step in Caulobacter flagellar assembly. Mohr CD, MacKichan JK, Shapiro L; J Bacteriol. 1998;180:2175-2185. PMID:9555902