Abstract
Mutations inSalmonella typhimurium fliG, fliMandfliNgive rise either to non-flagellate, non-motile or non-chemotactic mutant bacteria. The FliG, FliM and FliN proteins form part of recently characterized extended flagellar basal structures, and have been postulated to form a mutually interacting structural complex. We have examined basal body preparations from non-motile or non-chemotacticfliG, fliMandfliNmutant strains by electron microscopy and immunoblot gel analysis. Most flagellar preparations isolated from the non-motile mutants lacked FliM, but contained FliG. The basal bodies lacked the belled morphology characteristic of the wild-type structures, but had protrusions which could be labelled with anti-FliG. Non-motile mutant preparations severely depleted of FliG but containing FliM were also obtained. These preparations contained extended, belled flagellar structures that were labelled with anti-FliM. Thus, FliM is part of the shell of the extended structures responsible for the belled morphology, while FliG may be part of the inner substructure. The extended basal structures from a FliG temperature-sensitive mutant strain rapidly lost FliM, as well as FliG, upon a shift to a non-permissive temperature, implying interaction between the FliG- and FliM-containing substructures. In dramatic contrast to non-motile mutants, extended basal structures isolated from non-chemotactic mutants were indistinguishable from wild-type structures. This difference may reflect the energetics of the different protein-protein interactions operative during torque generation and the switching of rotation sense.
| Original language | English (US) |
|---|---|
| Pages (from-to) | 400-412 |
| Number of pages | 13 |
| Journal | Journal of Molecular Biology |
| Volume | 251 |
| Issue number | 3 |
| DOIs | |
| State | Published - Aug 18 1995 |
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Keywords
- bacterial chemotaxis
- flagellar basal body
- immunoelectron microscopy
- molecular motor
- protein-protein interactions
ASJC Scopus subject areas
- Molecular Biology
- Virology
Cite this
Structural Effects of Mutations inSalmonella typhimuriumFlagellar Switch Complex. / Zhao, Rongbao; Schuster, Stephan C.; Khan, Shahid.
In: Journal of Molecular Biology, Vol. 251, No. 3, 18.08.1995, p. 400-412.Research output: Contribution to journal › Article
}
TY - JOUR
T1 - Structural Effects of Mutations inSalmonella typhimuriumFlagellar Switch Complex
AU - Zhao, Rongbao
AU - Schuster, Stephan C.
AU - Khan, Shahid
PY - 1995/8/18
Y1 - 1995/8/18
N2 - Mutations inSalmonella typhimurium fliG, fliMandfliNgive rise either to non-flagellate, non-motile or non-chemotactic mutant bacteria. The FliG, FliM and FliN proteins form part of recently characterized extended flagellar basal structures, and have been postulated to form a mutually interacting structural complex. We have examined basal body preparations from non-motile or non-chemotacticfliG, fliMandfliNmutant strains by electron microscopy and immunoblot gel analysis. Most flagellar preparations isolated from the non-motile mutants lacked FliM, but contained FliG. The basal bodies lacked the belled morphology characteristic of the wild-type structures, but had protrusions which could be labelled with anti-FliG. Non-motile mutant preparations severely depleted of FliG but containing FliM were also obtained. These preparations contained extended, belled flagellar structures that were labelled with anti-FliM. Thus, FliM is part of the shell of the extended structures responsible for the belled morphology, while FliG may be part of the inner substructure. The extended basal structures from a FliG temperature-sensitive mutant strain rapidly lost FliM, as well as FliG, upon a shift to a non-permissive temperature, implying interaction between the FliG- and FliM-containing substructures. In dramatic contrast to non-motile mutants, extended basal structures isolated from non-chemotactic mutants were indistinguishable from wild-type structures. This difference may reflect the energetics of the different protein-protein interactions operative during torque generation and the switching of rotation sense.
AB - Mutations inSalmonella typhimurium fliG, fliMandfliNgive rise either to non-flagellate, non-motile or non-chemotactic mutant bacteria. The FliG, FliM and FliN proteins form part of recently characterized extended flagellar basal structures, and have been postulated to form a mutually interacting structural complex. We have examined basal body preparations from non-motile or non-chemotacticfliG, fliMandfliNmutant strains by electron microscopy and immunoblot gel analysis. Most flagellar preparations isolated from the non-motile mutants lacked FliM, but contained FliG. The basal bodies lacked the belled morphology characteristic of the wild-type structures, but had protrusions which could be labelled with anti-FliG. Non-motile mutant preparations severely depleted of FliG but containing FliM were also obtained. These preparations contained extended, belled flagellar structures that were labelled with anti-FliM. Thus, FliM is part of the shell of the extended structures responsible for the belled morphology, while FliG may be part of the inner substructure. The extended basal structures from a FliG temperature-sensitive mutant strain rapidly lost FliM, as well as FliG, upon a shift to a non-permissive temperature, implying interaction between the FliG- and FliM-containing substructures. In dramatic contrast to non-motile mutants, extended basal structures isolated from non-chemotactic mutants were indistinguishable from wild-type structures. This difference may reflect the energetics of the different protein-protein interactions operative during torque generation and the switching of rotation sense.
KW - bacterial chemotaxis
KW - flagellar basal body
KW - immunoelectron microscopy
KW - molecular motor
KW - protein-protein interactions
UR - http://www.scopus.com/inward/record.url?scp=0029091434&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=0029091434&partnerID=8YFLogxK
U2 - 10.1006/jmbi.1995.0443
DO - 10.1006/jmbi.1995.0443
M3 - Article
C2 - 7650739
AN - SCOPUS:0029091434
VL - 251
SP - 400
EP - 412
JO - Journal of Molecular Biology
JF - Journal of Molecular Biology
SN - 0022-2836
IS - 3
ER -