Jump to content

Flagellar motor switch protein

From Wikipedia, the free encyclopedia
(Redirected from FliG)
FliG C-terminal domain
crystal structure of the middle and c-terminal domains of the flagellar rotor protein flig
Identifiers
SymbolFliG_C
PfamPF01706
Pfam clanCL0436
InterProIPR000090
SCOP21qc7 / SCOPe / SUPFAM
Available protein structures:
Pfam  structures / ECOD  
PDBRCSB PDB; PDBe; PDBj
PDBsumstructure summary
Flagellar motor switch protein FliM
Identifiers
SymbolFliM
PfamPF02154
Pfam clanCL0355
InterProIPR001689
Available protein structures:
Pfam  structures / ECOD  
PDBRCSB PDB; PDBe; PDBj
PDBsumstructure summary

In molecular biology, the flagellar motor switch protein (Flig) is one of three proteins in certain bacteria coded for by the gene fliG.[1] The other two proteins are FliN coded for by fliN,[2] and FliM coded for by fliM.[3] The protein complex regulates the direction of flagellar rotation and hence controls swimming behaviour.[4] The switch is a complex apparatus that responds to signals transduced by the chemotaxis sensory signalling system during chemotactic behaviour.[4] CheY, the chemotaxis response regulator, is believed to act directly on the switch to induce a switch in the flagellar motor direction of rotation.

Fli proteins

[edit]

The switch complex comprises at least three proteins: FliG, FliM and FliN.[2] It has been shown that FliG interacts with FliM, FliM interacts with itself, and FliM interacts with FliN.[5] Several amino acids 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.[5] 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.[6] 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.[6][7] FliG is present in about 25 copies per flagellum. The structure of the C-terminal domain of FliG is known, this domain functions specifically in motor rotation.[8]

References

[edit]
  1. ^ "flig in UniProtKB". www.uniprot.org. Retrieved 21 March 2022.
  2. ^ a b "fliN - Flagellar motor switch protein FliN - Salmonella typhimurium (strain LT2 / SGSC1412 / ATCC 700720) - fliN gene & protein". www.uniprot.org. Retrieved 21 March 2022.
  3. ^ "flim in UniProtKB". www.uniprot.org. Retrieved 21 March 2022.
  4. ^ a b Roman SJ, Frantz BB, Matsumura P (October 1993). "Gene sequence, overproduction, purification and determination of the wild-type level of the Escherichia coli flagellar switch protein FliG". Gene. 133 (1): 103–108. doi:10.1016/0378-1119(93)90232-R. PMID 8224881.
  5. ^ a b Marykwas DL, Berg HC (March 1996). "A mutational analysis of the interaction between FliG and FliM, two components of the flagellar motor of Escherichia coli". Journal of Bacteriology. 178 (5): 1289–1294. doi:10.1128/jb.178.5.1289-1294.1996. PMC 177801. PMID 8631704.
  6. ^ a b Kihara M, Homma M, Kutsukake K, Macnab RM (June 1989). "Flagellar switch of Salmonella typhimurium: gene sequences and deduced protein sequences". Journal of Bacteriology. 171 (6): 3247–3257. doi:10.1128/jb.171.6.3247-3257.1989. PMC 210043. PMID 2656645.
  7. ^ Francis NR, Irikura VM, Yamaguchi S, DeRosier DJ, Macnab RM (July 1992). "Localization of the Salmonella typhimurium flagellar switch protein FliG to the cytoplasmic M-ring face of the basal body". Proceedings of the National Academy of Sciences U.S.A. 89 (14): 6304–6308. Bibcode:1992PNAS...89.6304F. doi:10.1073/pnas.89.14.6304. PMC 49489. PMID 1631122.
  8. ^ Lloyd SA, Whitby FG, Blair DF, Hill CP (July 1999). "Structure of the C-terminal domain of FliG, a component of the rotor in the bacterial flagellar motor". Nature. 400 (6743): 472–475. Bibcode:1999Natur.400..472L. doi:10.1038/22794. PMID 10440379. S2CID 4367420.
This article incorporates text from the public domain Pfam and InterPro: IPR001689
This article incorporates text from the public domain Pfam and InterPro: IPR000090