Project description:Identification of the specific WalR (YycF) binding regions on the B. subtilis chromosome during exponential and phosphate starvation growth phases. The data serves to extend the WalRK regulon in Bacillus subtilis and its role in cell wall metabolism, as well as implying a role in several other cellular processes. For each sample analyzed in this study three biological replicates were performed. Three different samples were taken from a strain expressing the WalR-SPA protein as well as from wild-type (168) without a tagged WalR. Samples were taken from exponentially growing cells in low phosphate medium (LPDM) as well as from phosphate-limited cells (T2). Each sample compares ChIP DNA vs. Total DNA from the same cells.
Project description:The nucleotide (p)ppGpp is crucial for viability during amino acid limitation in bacteria, yet how it accomplishes this remains unknown. We found that the absence of (p)ppGpp in Bacillus subtilis cells leads to multiple amino acid auxotrophy, and that (p)ppGpp allows for prototrophy by reducing GTP levels. We provide evidence that reduction of GTP levels relieves the requirements for branched-chain amino acids primarily by preventing hyperactivity of the GTP-dependent transcriptional regulator CodY, but that GTP levels can also play an important role in regulating transcription of many amino acid biosynthesis genes independently of CodY. Thus, CodY-dependent and independent regulation of transcription by GTP levels plays overlapping yet distinct physiological roles in allowing amino acid prototrophy. Finally, supplementing these required amino acids does not protect against cell death upon nutrient downshift, but allows for sustained growth following this transition. We conclude that regulation of GTP levels by (p)ppGpp allows cells to adapt to conditions of amino acid limitation by first allowing survival during shifting nutrient conditions, and then allowing amino acid prototrophy by transcriptionally regulating amino acid biosynthesis. This strategy may be used to ensure viability during amino acid limitation in evolutionarily divergent bacteria. Twelve-condition experiment: wt, wt+RHX, wt+Guo, (p)ppGpp0, (p)ppGpp0+RHX, (p)ppGpp0+Guo, M-NM-^TcodY (p)ppGpp0, M-NM-^TcodY (p)ppGpp0+RHX, M-NM-^TcodY (p)ppGpp0+Guo, guaB- (p)ppGpp0, guaB- (p)ppGpp0+RHX, guaB- (p)ppGpp0+Guo. Biological replicates: 3 for each sample. Reference: a mixture of wt RNA from different growth phases and wt backgrounds.
Project description:Here we use Structure-seq2 to probe the in vivo RNA structurome of B. subtilis grown in the presence and absence of amino acids. We show that the change in global RNA structurome is inversely proportional to the change in abundance upon amino acid starvation and that this trend is pronounced in the stringent response and codY regulons. We also use this data to characterize known and novel RNA switches.
Project description:Bacillus subtilis is exposed to a wide range of transitory stress and starvation conditions. Here we investigate the expression changes observed in the B. subtilis wild type strain 168 and its isogenic sigB mutant(BSM29) with respect to each stress condition tested.
Project description:Identification of the specific WalR (YycF) binding regions on the B. subtilis chromosome during exponential and phosphate starvation growth phases. The data serves to extend the WalRK regulon in Bacillus subtilis and its role in cell wall metabolism, as well as implying a role in several other cellular processes.
Project description:Actively dividing cells perform robust and accurate DNA replication during fluctuating nutrient availability, yet factors that prevent disruption of replication remain largely unknown. Here we report that DksA, a nutrient-responsive transcription factor, ensures replication completion in Escherichia coli. In the absence of DksA, replication is rapidly arrested upon amino acid starvation. This replication arrest occurs independently of exogenous DNA damage, yet it induces the DNA damage response and recruits the main recombination protein RecA. This microarray experiment compares the transcriptional responses to amino acid starvation in wild-type and delta dksA cells. The SOS-regulated genes are highly induced in delta dksA cells.
Project description:Transcriptional response of Bacillus subtilis to ramoplanin in wild-type CU1065. Bacillus subtilis CU1065, WT (-RAM) vs. (+RAM) and liaR (yvqC) deletion (-RAM) vs. (+RAM). The experiment was conducted in triplicate using three independent total RNA preparations. Combined reference RNA was labeled with Cy3 and ramoplanin treated/untreated samples were labeled with Cy5.
