1. ROMAN, S.J., FRANTZ, B.B. AND MATSUMURA, P.
Gene sequence, overproduction, purification and determination of the
wild-type level of the Escherichia coli flagellar switch protein FliG.
GENE 133 103-108 (1993).
2. MARYKWAS, D.L. AND BERG, H.C.
A mutational analysis of the interaction between FliG and FliM, two
components of the flagellar motor of Escherichia coli.
J.BACTERIOL. 178 1289-1294 (1996).
3. KIHARA, M., HOMMA, M., KUTSUKAKE, K. AND MACNAB, R.M.
Flagellar switch of Salmonella typhimurium: gene sequences and deduced
J.BACTERIOL. 171 3247-3257 (1989).
4. FRANCIS, N.R., IRIKURA, V.M., YAMAGUCHI, S., DEROSIER, D.J.
AND MACNAB, R.M.
Localization of the Salmonella typhimurium flagellar switch protein FliG to
the cytoplasmic M-ring face of the basal body.
PROC.NATL.ACAD.SCI.U.S.A. 89 6304-6308 (1992).
The flagellar motor switch in E.coli and S.typhimurium regulates the
direction of flagellar rotation and hence controls swimming behaviour .
The switch is a complex apparatus that responds to signals transduced by the
chemotaxis sensory signalling system during chemotactic behaviour . 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 . 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 . 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 . 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 [3,4].
FLGMOTORFLIM is a 4-element fingerprint that provides a signature for
flagellar motor switch FliM proteins. The fingerprint was derived from
an initial alignment of 5 sequences: the motifs were drawn from short
conserved regions spanning the central portion of alignment. Two iterations
on OWL30.2 were required to reach convergence, at which point a true set
comprising 7 sequences was identified. A single partial matches was also
found, TPU324754, a fragment from Treponema phagedenis that matches motifs
1 and 2.
An update on SPTR37_9f identified a true set of 7 sequences.