Flagellar motor switch protein FliM (IPR001689)

Short name: Flag_FliM

Overlapping homologous superfamilies

Family relationships



The flagellar motor switch in Escherichia coli and Salmonella typhimurium regulates the direction of flagellar rotation and hence controls swimming behaviour [PMID: 8224881]. The switch is a complex apparatus that responds to signals transduced by the chemotaxis sensory signalling system during chemotactic behaviour [PMID: 8224881]. CheY, the chemotaxis response regulator, is believed to act directly on the switch to induce tumbles in the swimming pattern, but no physical interactions of CheY and switch proteins have yet been demonstrated.

The switch complex comprises at least three proteins - FliG, FliM and FliN. It has been shown that FliG interacts with FliM, FliM interacts with itself, and FliM interacts with FliN [PMID: 8631704]. Several residues within the middle third of FliG appear to be strongly involved in the FliG-FliM interaction, with residues near the N or C termini being less important [PMID: 8631704]. Such clustering suggests that FliG-FliM interaction plays a central role in switching.

Analysis of the FliG, FliM and FliN sequences shows that none are especially hydrophobic or appear to be integral membrane proteins [PMID: 2656645]. This result is consistent with other evidence suggesting that the proteins may be peripheral to the membrane, possibly mounted on the basal body M ring [PMID: 2656645, PMID: 1631122].

GO terms

Biological Process

GO:0071973 bacterial-type flagellum-dependent cell motility

Molecular Function

GO:0003774 motor activity

Cellular Component

GO:0009425 bacterial-type flagellum basal body

Contributing signatures

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