The RpoS subunit of RNA polymerase controls the expression of numerous genes involved in stationary phase and in response to different stress conditions. The regulatory protein Crl increases the activity of RpoS by direct interaction with the RpoS holoenzyme. To define the extent of the Crl regulon, we used two-dimensional SDSPAGE to measure the role of Crl in regulating the expression of the E...

DNA arrays of the entire set of Escherichia coli genes were used to measure the genomic expression patterns of cells growing in late logarithmic phase on minimal glucose medium and on Luria broth containing glucose. Ratios of the transcript levels for all 4,290 E. coli protein-encoding genes (cds) were obtained, and analysis of the expression ratio data indicated that the physiological state of...

In Azotobacter vinelandii, a cyst-forming bacterium, the alternative sigma factor RpoS is essential to the formation of cysts resistant to desiccation and to synthesis of the cyst-specific lipids, alkylresorcinols. In this study, we carried out a proteome analysis of vegetative cells and cysts of A. vinelandii strain AEIV and its rpoS mutant derivative AErpoS. This analysis allowed us to identi...

We report a crystal structure of Hfq and catalase HPII from Escherichia coli. The post-transcriptional regulator Hfq plays a key role in the survival of bacteria under stress. A small non-coding RNA (sRNA) DsrA is required for translation of the stationary phase sigma factor RpoS, which is the central regulator of the general stress response. Hfq facilitates efficient translation of rpoS mRNA, ...

The mutS-rpoS region is known to be a highly polymorphic segment of the chromosome owing to horizontal gene transfer and evolutionary processes. In Pseudomonas, mutS-fdxA-rsmZ-rpoS organization is highly conserved, as well as the promoter region of the RsmZ small RNA (sRNA)-encoding gene. One exception to this conservation is in Pseudomonas brassicacearum, where a 308-nucleotide (nt) sequence, ...

High-level production of human leptin by fed-batch culture of recombinant Escherichia coli using constitutive promoter system was investigated. For the constitutive expression of the obese gene encoding human leptin, the strong constitutive HCE promoter cloned from the D-amino acid aminotransferase gene of Geobacillus toebii was used. To develop an optimal host-vector system, several different ...

In Pseudomonas fluorescens biocontrol strain CHA0, the two-component system GacS/GacA positively controls the synthesis of extracellular products such as hydrogen cyanide, protease, and 2,4-diacetylphloroglucinol, by upregulating the transcription of small regulatory RNAs which relieve RsmA-mediated translational repression of target genes. The expression of the stress sigma factor sigmaS (RpoS...

Persisters comprise a group of phenotypically heterogeneous metabolically quiescent bacteria with multidrug tolerance and contribute to the recalcitrance of chronic infections. Although recent work has shown that toxin-antitoxin (TA) system HipAB depends on stringent response effector (p)ppGppin persister formation, whether other persister pathways are also dependent on stringent response has n...

Legionella pneumophila possesses a variety of secreted and cell-associated hydrolytic activities that could be involved in pathogenesis. The activities include phospholipase A, lysophospholipase A, glycerophospholipid:cholesterol acyltransferase, lipase, protease, phosphatase, RNase, and p-nitrophenylphosphorylcholine (p-NPPC) hydrolase. Up to now, there have been no data available on the regul...

The antiadaptor protein IraD inhibits the proteolysis of the alternative sigma factor, RpoS, which promotes the synthesis of >100 genes during the general stress response and during stationary phase. Our previous results showed that IraD determines RpoS steady-state levels during exponential growth and mediates its stabilization after DNA damage. In this study, we show by promoter fusions that ...