Editor: Olga Ozoline
Probing flagellar promoter occupancy in wild-type and mutant Caulobacter crescentus by chromatin immunoprecipitation
Article first published online: 19 APR 2011
© 2011 Federation of European Microbiological Societies. Published by Blackwell Publishing Ltd. All rights reserved
FEMS Microbiology Letters
Volume 319, Issue 2, pages 146–152, June 2011
How to Cite
Davis, N. J. and Viollier, P. H. (2011), Probing flagellar promoter occupancy in wild-type and mutant Caulobacter crescentus by chromatin immunoprecipitation. FEMS Microbiology Letters, 319: 146–152. doi: 10.1111/j.1574-6968.2011.02275.x
- Issue published online: 17 MAY 2011
- Article first published online: 19 APR 2011
- Accepted manuscript online: 2 APR 2011 07:37AM EST
- Received 21 January 2011; revised 25 March 2011; accepted 28 March 2011., Final version published online 19 April 2011.
In the asymmetric predivisional cell of Caulobacter crescentus, TipF and TipN mark the cellular pole for future flagellar development. TipF is essential for motility and contains a cyclic-di-GMP phosphodiesterase-like (EAL) domain that is necessary for proper function. TipN is localized to the flagellar pole before TipF and is essential for the proper placement of the flagellum in C. crescentus. Using β-galactosidase promoter-probe assays and quantitative chromatin immunoprecipitation, we investigated the influence of the C. crescentus flagellar assembly regulator TipF on flagellar gene transcription. We compared the transcriptional activity of class II-fliF-lacZ, class III-flgE-lacZ, and class IV-fljL-lacZ fusions in a ΔtipF mutant with that of other flagellar mutants and the wild-type strain. We subsequently verified the in vivo occupancy of the fliF, flgE, and fljL flagellar promoters by the flagellar regulators CtrA, FlbD, and FliX in addition to RNA polymerase. We deduce that TipF contributes to proper expression of flagellar genes in C. crescentus by acting both within and outside of the canonical flagellar gene expression hierarchy.