Skip to main content
Article thumbnail
Location of Repository

Transcriptional and mutational analyses of the rpoN operon in Caulobacter crescentus.

By R S Janakiraman and Y V Brun


The alternative sigma factor sigma54 is required for the biogenesis of both the flagellum and the stalk in Caulobacter crescentus. The DNA sequence downstream of the sigma54 gene (rpoN) has been determined, revealing three open reading frames (ORFs) encoding peptides of 203, 208, and 159 amino acids. ORF208 and ORF159 are homologous to ORFs found downstream of rpoN in other microorganisms. The organization of this region in C. crescentus is similar to that in other bacteria, with the exception of an additional ORF, ORF203, immediately downstream from rpoN. There is a single temporally regulated promoter that drives the expression of both rpoN and ORF203. Promoter probe analysis indicates the presence of another promoter downstream from ORF203 which exhibits a temporal control that is different from that of the rpoN promoter. Mutational analysis was used to address the function of the proteins encoded by these three downstream ORFs. The mutations have no effect on the transcription of previously known sigma54-dependent flagellar promoters except for a slight effect of an ORF159 mutation on transcription of fljK

Topics: Research Article
Year: 1997
OAI identifier:
Provided by: PubMed Central
Sorry, our data provider has not provided any external links therefore we are unable to provide a link to the full text.

Suggested articles

To submit an update or takedown request for this paper, please submit an Update/Correction/Removal Request.