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Direct interaction of FliX and FlbD is required for their regulatory activity in Caulobacter crescentus
BACKGROUND: The temporal and spatial expression of late flagellar genes in Caulobacter crescentus is activated by the transcription factor FlbD and its partner trans-acting factor FliX. The physical interaction of these two proteins represents an alternative mechanism for regulating the activity of...
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Formato: | Texto |
Lenguaje: | English |
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BioMed Central
2011
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Acceso en línea: | https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3096577/ https://www.ncbi.nlm.nih.gov/pubmed/21535897 http://dx.doi.org/10.1186/1471-2180-11-89 |
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author | Xu, Zhaohui Dutton, Rachel J Gober, James W |
author_facet | Xu, Zhaohui Dutton, Rachel J Gober, James W |
author_sort | Xu, Zhaohui |
collection | PubMed |
description | BACKGROUND: The temporal and spatial expression of late flagellar genes in Caulobacter crescentus is activated by the transcription factor FlbD and its partner trans-acting factor FliX. The physical interaction of these two proteins represents an alternative mechanism for regulating the activity of σ(54 )transcription factors. This study is to characterize the interaction of the two proteins and the consequences of the interaction on their regulatory activity. RESULTS: FliX and FlbD form stable complexes, which can stand the interference of 2.65 M NaCl. The stability of FliX and FlbD was affected by the co-existence of each other. Five FliX mutants (R71A, L85K, Δ117-118, T130L, and L136K) were created by site-directed mutagenesis in conserved regions of the protein. All mutants were successfully expressed in both wild-type and ΔfliX Caulobacter strains. All but FliX(L85K )could rescue the motility and cell division defects of a ΔfliX mutant strain. The ability of FliX to regulate the transcription of class II and class III/IV flagellar promoters was fully diminished due to the L85K mutation. Co-immunoprecipitation experiment revealed that FliX(L85K )was unable to physically interact with FlbD. CONCLUSIONS: FliX interacts with FlbD and thereby directly regulates the activity of FlbD in response to flagellar assembly. Mutations in highly conserved regions of FliX could severely affect the recognition between FliX and FlbD and hence interrupt the normal progression of flagellar synthesis and other developmental events in Caulobacter. |
format | Text |
id | pubmed-3096577 |
institution | National Center for Biotechnology Information |
language | English |
publishDate | 2011 |
publisher | BioMed Central |
record_format | MEDLINE/PubMed |
spelling | pubmed-30965772011-05-18 Direct interaction of FliX and FlbD is required for their regulatory activity in Caulobacter crescentus Xu, Zhaohui Dutton, Rachel J Gober, James W BMC Microbiol Research Article BACKGROUND: The temporal and spatial expression of late flagellar genes in Caulobacter crescentus is activated by the transcription factor FlbD and its partner trans-acting factor FliX. The physical interaction of these two proteins represents an alternative mechanism for regulating the activity of σ(54 )transcription factors. This study is to characterize the interaction of the two proteins and the consequences of the interaction on their regulatory activity. RESULTS: FliX and FlbD form stable complexes, which can stand the interference of 2.65 M NaCl. The stability of FliX and FlbD was affected by the co-existence of each other. Five FliX mutants (R71A, L85K, Δ117-118, T130L, and L136K) were created by site-directed mutagenesis in conserved regions of the protein. All mutants were successfully expressed in both wild-type and ΔfliX Caulobacter strains. All but FliX(L85K )could rescue the motility and cell division defects of a ΔfliX mutant strain. The ability of FliX to regulate the transcription of class II and class III/IV flagellar promoters was fully diminished due to the L85K mutation. Co-immunoprecipitation experiment revealed that FliX(L85K )was unable to physically interact with FlbD. CONCLUSIONS: FliX interacts with FlbD and thereby directly regulates the activity of FlbD in response to flagellar assembly. Mutations in highly conserved regions of FliX could severely affect the recognition between FliX and FlbD and hence interrupt the normal progression of flagellar synthesis and other developmental events in Caulobacter. BioMed Central 2011-05-02 /pmc/articles/PMC3096577/ /pubmed/21535897 http://dx.doi.org/10.1186/1471-2180-11-89 Text en Copyright ©2011 Xu et al; licensee BioMed Central Ltd. http://creativecommons.org/licenses/by/2.0 This is an Open Access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/2.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited. |
spellingShingle | Research Article Xu, Zhaohui Dutton, Rachel J Gober, James W Direct interaction of FliX and FlbD is required for their regulatory activity in Caulobacter crescentus |
title | Direct interaction of FliX and FlbD is required for their regulatory activity in Caulobacter crescentus |
title_full | Direct interaction of FliX and FlbD is required for their regulatory activity in Caulobacter crescentus |
title_fullStr | Direct interaction of FliX and FlbD is required for their regulatory activity in Caulobacter crescentus |
title_full_unstemmed | Direct interaction of FliX and FlbD is required for their regulatory activity in Caulobacter crescentus |
title_short | Direct interaction of FliX and FlbD is required for their regulatory activity in Caulobacter crescentus |
title_sort | direct interaction of flix and flbd is required for their regulatory activity in caulobacter crescentus |
topic | Research Article |
url | https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3096577/ https://www.ncbi.nlm.nih.gov/pubmed/21535897 http://dx.doi.org/10.1186/1471-2180-11-89 |
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