Flagellar hook-basal body complex protein FliE (IPR001624)

Short name: FliE

Overlapping homologous superfamilies


Family relationships



Four genes from the major Bacillus subtilis chemotaxis locus have been shown to encode proteins that are similar to the Salmonella typhimurium FlgB, FlgC, FlgG and FliF proteins; a further gene product is similar to the Escherichia coli FliE protein [PMID: 1905667]. All of these proteins are thought to form part of the hook-basal body complex of the bacterial flagella [PMID: 1905667]. The FlgB, FlgC and FlgG proteins are components of the proximal and distal rods; FliF forms the M-ring that anchors the rod assembly to the membrane; but the role of FliE has not yet been determined [PMID: 1905667]. The similarity between the proteins in these two organisms suggests that the structures of the M-ring and the rod may be similar [PMID: 1905667]. Nevertheless, some differences in size and amino acid composition between some of the homologues suggest the basal body proteins may be organised slightly differently within B. subtilis [PMID: 1905667].

From gel electrophoresis and autoradiography of 35S-labelled S. typhimurium hook-basal body complexes and the deduced number of sulphur-containing residues in FliE, the stoichiometry of the protein in the hook-basal body complex has been estimated to be about nine subunits [PMID: 1551848]. FliE does not undergo cleavage of a signal peptide, nor does it show any similarity to the axial components like the rod or hook proteins, which are thought to be exported by the flagellum-specific export pathway [PMID: 1551848]. On this evidence, it has been suggested that FliE may be in the vicinity of the MS ring, perhaps acting as an adaptor protein between ring and rod substructures [PMID: 1551848].

GO terms

Biological Process

GO:0071973 bacterial-type flagellum-dependent cell motility

Molecular Function

GO:0003774 motor activity
GO:0005198 structural molecule activity

Cellular Component

GO:0009288 bacterial-type flagellum

Contributing signatures

Signatures from InterPro member databases are used to construct an entry.