An unusual promoter controls cell‐cycle regulation and dependence on DNA replication of the Caulobacter fliLM early flagellar operon
- 1 September 1993
- journal article
- research article
- Published by Wiley in Molecular Microbiology
- Vol. 9 (6), 1169-1179
- https://doi.org/10.1111/j.1365-2958.1993.tb01246.x
Abstract
Transcription of flagellar genes in Caulobacter crecentus is programmed to occur during the predivisional stage of the cell cycle. The mechanism of activation of Class II flagellar genes, the highest identified genes in the Caulobacter flagellar hierarchy, is unknown. As a step toward understanding this process, we have defined cis-acting sequences necessary for expression of a Class II flagellar operon, fliLM. Deletion analysis indicated that a 55 bp DNA fragment was sufficient for normal, temporally regulated promoter activity. Transcription from this promoter-containing fragment was severely reduced when chromosomal DNA replication was inhibited. Extensive mutational analysis of the promoter region from -42 to -5 identified functionally important nucleotides at -36 and -35, between -29 and -22, and at -12, which correlates well with sequences conserved between fliLM and the analogous regions of two other Class II flagellar operons. The promoter sequence does not resemble that recognized by any known bacterial sigma factor. Models for regulation of Caulobacter early flagellar promoters are discussed in which RNA polymerase containing a novel sigma subunit interacts with an activation factor bound to the central region of the promoter.Keywords
This publication has 46 references indexed in Scilit:
- DNA mismatch repair-induced double-strand breaksDNA Repair, 2007
- Organization and ordered expression of Caulobacter genes encoding flagellar basal body rod and ring proteinsJournal of Molecular Biology, 1992
- Plasmid and chromosomal DNA replication and partitioning during the Caulobacter crescentus cell cycleJournal of Molecular Biology, 1990
- A reliable method for random mutagenesis: the generation of mutant libraries using spiked oligodeoxyribonucleotide primersGene, 1989
- A set of positively regulated flagellar gene promoters in Caulobacter crescentus with sequence homology to the nif gene promoters of Klebsiella pneumoniaeJournal of Molecular Biology, 1987
- Cascade regulation of Caulobacter flagellar and chemotaxis genesJournal of Molecular Biology, 1987
- Sequence determinants of promoter activityCell, 1982
- E. coli RNA polymerase interacts homologously with two different promotersCell, 1980
- Temporal control of the cell cycle in Caulobacter crescentus: Roles of DNA chain elongation and completionJournal of Molecular Biology, 1980
- Regulation of flagellin synthesis in the cell cycle of Caulobacter: Dependence on DNA replicationCell, 1977