scholarly journals Regulation of Bacterial DNA Packaging in Early Stationary Phase by Competitive DNA Binding of Dps and IHF

2015 ◽  
Vol 5 (1) ◽  
Author(s):  
Sin Yi Lee ◽  
Ci Ji Lim ◽  
Peter Dröge ◽  
Jie Yan
Keyword(s):  
Dna Binding ◽  
Stationary Phase ◽  
Dna Packaging ◽  
Early Stationary Phase ◽  
Bacterial Dna

scholarly journals 6S RNA regulation of relA alters ppGpp levels in early stationary phase

Microbiology ◽  
2010 ◽  
Vol 156 (12) ◽  
pp. 3791-3800 ◽  
Author(s):  
Amy T. Cavanagh ◽  
Pete Chandrangsu ◽  
Karen M. Wassarman
Keyword(s):  
Amino Acid ◽  
Stationary Phase ◽  
Regulation Of Transcription ◽  
Early Stationary Phase ◽  
Rna Regulation ◽  
Global Regulators ◽  
Expression Of Genes ◽  
Non Coding Rna ◽  
6S Rna ◽  
Altered Regulation

6S RNA is a small, non-coding RNA that interacts directly with σ 70-RNA polymerase and regulates transcription at many σ 70-dependent promoters. Here, we demonstrate that 6S RNA regulates transcription of relA, which encodes a ppGpp synthase. The 6S RNA-dependent regulation of relA expression results in increased ppGpp levels during early stationary phase in cells lacking 6S RNA. These changes in ppGpp levels, although modest, are sufficient to result in altered regulation of transcription from σ 70-dependent promoters sensitive to ppGpp, including those promoting expression of genes involved in amino acid biosynthesis and rRNA. These data place 6S RNA as another player in maintaining appropriate gene expression as cells transition into stationary phase. Independent of this ppGpp-mediated 6S RNA-dependent regulation, we also demonstrate that in later stationary phase, 6S RNA continues to downregulate transcription in general, and specifically at a subset of the amino acid promoters, but through a mechanism that is independent of ppGpp and which we hypothesize is through direct regulation. In addition, 6S RNA-dependent regulation of σ S activity is not mediated through observed changes in ppGpp levels. We suggest a role for 6S RNA in modulating transcription of several global regulators directly, including relA, to downregulate expression of key pathways in response to changing environmental conditions.

scholarly journals Activation of RAW264.7 Macrophages by Bacterial DNA and Lipopolysaccharide Increases Cell Surface DNA Binding and Internalization

2004 ◽  
Vol 279 (17) ◽  
pp. 17217-17223 ◽  
Author(s):  
Sharon L. McCoy ◽  
Stephen E. Kurtz ◽  
Frances A. Hausman ◽  
Dennis R. Trune ◽  
Robert M. Bennett ◽  
...  
Keyword(s):  
Dna Binding ◽  
Cell Surface ◽  
Bacterial Dna ◽  
Raw264.7 Macrophages

scholarly journals Enhancement of plasmid DNA transformation efficiencies in early stationary-phase yeast cell cultures

Yeast ◽  
2013 ◽  
Vol 30 (5) ◽  
pp. 191-200 ◽  
Author(s):  
Jennifer DeMars Tripp ◽  
Jennifer L. Lilley ◽  
Whitney N. Wood ◽  
L. Kevin Lewis
Keyword(s):  
Stationary Phase ◽  
Yeast Cell ◽  
Cell Cultures ◽  
Plasmid Dna ◽  
Dna Transformation ◽  
Early Stationary Phase

The effect of sublethal heating on Staphylococcus aureus at different physiological ages

1974 ◽  
Vol 20 (5) ◽  
pp. 765-768 ◽  
Author(s):  
Andre Hurst ◽  
Ashton Hughes ◽  
David L. Collins-Thompson
Keyword(s):  
Staphylococcus Aureus ◽  
Stationary Phase ◽  
Heat Resistance ◽  
Growth Cycle ◽  
High Salt ◽  
Early Stationary Phase ◽  
Heat Injury ◽  
The Difference

Sublethal heat injury was measured by the difference in the numbers of colonies developing on trypticase soy agar and trypticase soy agar containing 7.5% NaCl. This difference was largest with late logarithmic and early stationary phase cells because, at this stage, cells had a greatly increased heat resistance. In contrast, the ability to form colonies on high salt agar after sublethal heating varied little during the growth cycle.

scholarly journals Dps Protects Cells against Multiple Stresses during Stationary Phase

2004 ◽  
Vol 186 (13) ◽  
pp. 4192-4198 ◽  
Author(s):  
Sudha Nair ◽  
Steven E. Finkel
Keyword(s):  
Oxidative Stress ◽  
Dna Binding ◽  
Stationary Phase ◽  
Regulation Of Gene Expression ◽  
Copper Toxicity ◽  
Metal Chelation ◽  
Archaeal Species ◽  
Acid And Base ◽  
Ferroxidase Activity

ABSTRACT Dps, the nonspecific DNA-binding protein from starved cells, is the most abundant protein in stationary-phase Escherichia coli. Dps homologs are found throughout the bacteria and in at least one archaeal species. Dps has been shown to protect cells from oxidative stress during exponential-phase growth. During stationary phase, Dps organizes the chromosome into a highly ordered, stable nucleoprotein complex called the biocrystal. We show here that Dps is required for long-term stationary-phase viability under competitive conditions and that dps mutants have altered lag phases compared to wild-type cells. We also show that during stationary phase Dps protects the cell not only from oxidative stress but also from UV and gamma irradiation, iron and copper toxicity, thermal stress, and acid and base shock. The protective roles of Dps are most likely achieved through a combination of functions associated with the protein-DNA binding and chromosome compaction, metal chelation, ferroxidase activity, and regulation of gene expression.

scholarly journals Phylogenetic and Functional Analysis of the Bacteriophage P1 Single-Stranded DNA-Binding Protein

2002 ◽  
Vol 76 (19) ◽  
pp. 9695-9701 ◽  
Author(s):  
Jannick Dyrløv Bendtsen ◽  
Anders S. Nilsson ◽  
Hansjörg Lehnherr
Keyword(s):  
Dna Binding ◽  
Stationary Phase ◽  
Binding Protein ◽  
Selective Advantage ◽  
Dna Binding Protein ◽  
Host Bacterium ◽  
Single Stranded Dna ◽  
Bacteriophage P1 ◽  
E Coli ◽  
Ssb Proteins

ABSTRACT Bacteriophage P1 encodes a single-stranded DNA-binding protein (SSB-P1), which shows 66% amino acid sequence identity to the SSB protein of the host bacterium Escherichia coli. A phylogenetic analysis indicated that the P1 ssb gene coexists with its E. coli counterpart as an independent unit and does not represent a recent acquirement of the phage. The P1 and E. coli SSB proteins are fully functionally interchangeable. SSB-P1 is nonessential for phage growth in an exponentially growing E. coli host, and it is sufficient to promote bacterial growth in the absence of the E. coli SSB protein. Expression studies showed that the P1 ssb gene is transcribed only, in an rpoS-independent fashion, during stationary-phase growth in E. coli. Mixed infection experiments demonstrated that a wild-type phage has a selective advantage over an ssb-null mutant when exposed to a bacterial host in the stationary phase. These results reconciled the observed evolutionary conservation with the seemingly redundant presence of ssb genes in many bacteriophages and conjugative plasmids.

scholarly journals Expression of Invasin and Motility Are Coordinately Regulated in Yersinia enterocolitica

1998 ◽  
Vol 180 (4) ◽  
pp. 793-800 ◽  
Author(s):  
Julie L. Badger ◽  
Virginia L. Miller
Keyword(s):  
Stationary Phase ◽  
Yersinia Enterocolitica ◽  
Growth Phase ◽  
Temperature Regulation ◽  
Molecular Basis ◽  
Early Stationary Phase ◽  
Regulatory Mutants ◽  
E Coli ◽  
Regulatory Mutant

ABSTRACT The Yersinia enterocolitica inv gene encodes the primary invasion factor invasin, which has been previously shown to be critical in the initial stages of infection. The expression ofinv is influenced by growth phase and temperature and is maximal during late exponential-early stationary phase at 23°C. In addition, motility of Y. enterocolitica is regulated by temperature. Y. enterocolitica cells are motile when grown at lower temperatures (30°C or below), while bacteria grown at 37°C are nonmotile. This study was initiated to determine the molecular basis for the temperature regulation of inv expression. Two mutants were isolated that both showed a significant decrease in invasin expression but are hypermotile when grown at 23°C. The first mutant (JB1A8v) was a result of a random mTn5Km insertion into the uvrC gene. The uvrC mutant JB1A8v demonstrated a significant decrease in inv and an increase in fleB (encodes flagellin) expression. These results suggest that expression of inv and flagellin genes is coordinated at the level of transcription. The second regulatory mutant, JB16v, was a result of a targeted insertion into a locus similar to sspA which in E. coli encodes a stationary-phase regulator. The E. coli sspA gene was cloned and assayed for complementation in both of the regulatory mutants. It was determined that E. coli sspA restored invasin expression in both the uvrC mutant and thesspA mutant. In addition, the complementing clone decreased flagellin levels in these mutants.

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