Project description:Transcriptome comparison of bguR mutant to wild-type in the Streptococcus pneumoniae D39 grown in GM17 The human pathogen Streptococcus pneumoniae has the ability to use the carbon- and energy source cellobiose due to the presence of a cellobiose-utilizing gene cluster (cel locus) in its genome. This system is regulated by the cellobiose-dependent transcriptional activator CelR, which has been previously shown to contribute to pneumococcal virulence. To get a broader understanding of the response of S. pneumoniae to cellobiose, we compared the pneumococcal transcriptome during growth on glucose as the main carbon source to that with cellobiose as the main carbon source. The expression of various carbon metabolic genes was altered, including a PTS operon (which we here denote as the bgu operon) that has high similarity with the cel locus. In contrast to the cel locus, the bgu operon is conserved in all sequenced strains of S. pneumoniae, indicating an important physiological function in the lifestyle of pneumococci. We next characterized the transcriptional regulation of the bgu operon in more detail. Its expression was increased in the presence of cellobiose, and decreased in the presence of glucose. A novel GntR-type transcriptional regulator (which we here denote as BguR) was shown to act as a transcriptional repressor of the bgu operon and its repressive effect was relieved in the presence of cellobiose. BguR-dependent repression was demonstrated to be mediated by a 20-bp DNA operator site (5M-bM-^@M-^Y-AAAAATGTCTAGACAAATTT-3M-bM-^@M-^Y) present in PbguA as verified by promoter truncation experiments. In conclusion, we have identified a new cellobiose-responsive PTS operon, together with its transcriptional regulator in S. pneumoniae. One condition design, comparison of two strains including a dye swap
Project description:The maltose regulon (mal regulon) has previously been shown to consist of the mal gene cluster (malQP, malXCD and malAR operons) in Streptococcus pneumoniae. In this study, we have further elucidated the complete mal regulon in S. pneumoniae D39 using microarray analyses and β-galactosidase assays. In addition to the mal gene cluster, the complete mal regulon of S. pneumoniae D39 consists of a pullulanase (PulA), a glucosidase (DexB), a glucokinase (RokB), a PTS component (PtsG) and an amylase (AmyA2). Our microarray studies and β-galactosidase assays further showed that the LacI-family transcriptional regulator MalR represses the expression of the mal regulon in the absence of maltose. Furthermore, the role of the pleiotropic transcriptional regulator CcpA in the regulation of the mal regulon in the presence of maltose was also explored. Our microarray analysis with a ΔccpA strain showed that CcpA only represses the expression of the malXCD operon and the pulA gene in the presence of maltose. Comparison of the Streptococcus pneumoniae D39 ccpA mutant compared to D39 wild type in MM17 (0.5 % (w/v) Maltose + M17) medium One condition design comparision of two strains including a dye swap
Project description:The maltose regulon (mal regulon) has previously been shown to consist of the mal gene cluster (malQP, malXCD and malAR operons) in Streptococcus pneumoniae. In this study, we have further elucidated the complete mal regulon in S. pneumoniae D39 using microarray analyses and β-galactosidase assays. In addition to the mal gene cluster, the complete mal regulon of S. pneumoniae D39 consists of a pullulanase (PulA), a glucosidase (DexB), a glucokinase (RokB), a PTS component (PtsG) and an amylase (AmyA2). Our microarray studies and β-galactosidase assays further showed that the LacI-family transcriptional regulator MalR represses the expression of the mal regulon in the absence of maltose. Furthermore, the role of the pleiotropic transcriptional regulator CcpA in the regulation of the mal regulon in the presence of maltose was also explored. Our microarray analysis with a ΔccpA strain showed that CcpA only represses the expression of the malXCD operon and the pulA gene in the presence of maltose. Comparison of the Streptococcus pneumoniae D39 malR mutant compared to D39 wild type in GM17 (0.5 % (w/v) Glucose + M17) medium One condition design comparision of two strains including a dye swap
Project description:In this study, we have explored the impact of ascorbic acid on the transcriptome of Streptococcus pneumoniae D39. The expression of several genes and operons, including the ula operon (which has been previously shown to be involved in ascorbic acid utilization), the AdcR regulon (which has been previously shown to be involved in zinc transport and virulence) and a PTS operon (which we denote here as ula2 operon) were altered in the presence of ascorbic acid. The ula2 operon consists of five genes, including the transcriptional activator ulaR2. Our M-NM-2-galactosidase assay data and transcriptome comparison of the ulaR2 mutant with the wild-type demonstrated that the transcriptional activator UlaR2 in the presence of ascorbic acid activates the expression of the ula2 operon. We further predict a 16-bp regulatory site (5M-bM-^@M-^Y-ATATTGTGCTCAAATA-3M-bM-^@M-^Y) for UlaR2 binding in the Pula2. Furthermore, we have explored the effect of ascorbic acid on the expression of the AdcR regulon. Our ICP-MS analysis showed that addition of ascorbic acid to the medium causes zinc starvation in the cell that leads to the activation of the AdcR regulon. Comparison of the Streptococcus pneumoniae D39 ulaR2 mutant compared to D39 wild type in M17 medium+ 10mM ascorbic acid (AM17) One condition design comparision of two strains including a dye swap
Project description:In this study, we have explored the impact of ascorbic acid on the transcriptome of Streptococcus pneumoniae D39. The expression of several genes and operons, including the ula operon (which has been previously shown to be involved in ascorbic acid utilization), the AdcR regulon (which has been previously shown to be involved in zinc transport and virulence) and a PTS operon (which we denote here as ula2 operon) were altered in the presence of ascorbic acid. The ula2 operon consists of five genes, including the transcriptional activator ulaR2. Our M-NM-2-galactosidase assay data and transcriptome comparison of the ulaR2 mutant with the wild-type demonstrated that the transcriptional activator UlaR2 in the presence of ascorbic acid activates the expression of the ula2 operon. We further predict a 16-bp regulatory site (5M-bM-^@M-^Y-ATATTGTGCTCAAATA-3M-bM-^@M-^Y) for UlaR2 binding in the Pula2. Furthermore, we have explored the effect of ascorbic acid on the expression of the AdcR regulon. Our ICP-MS analysis showed that addition of ascorbic acid to the medium causes zinc starvation in the cell that leads to the activation of the AdcR regulon. Comparison of the Streptococcus pneumoniae D39 compared to D39 wild type in M17 medium+ 10mM ascorbic acid (AM17) Two conditions design comparision of one strain including a dye swap
Project description:Transcriptome comparison of the Streptococcus pneumoniae D39 wild-type grown in CDM Plus 0mM Zn2+ to grown in CDM plus 0.2 mM Zn2+.
Project description:Transcriptome comparison of the Streptococcus pneumoniae D39 wild-type grown in M17 medium + 0.5 % (w/v) Lactose (LM17) to grown in M17 medium + 0.5 % (w/v) Glucose (GM17).
Project description:Transcriptome comparison of the Streptococcus pneumoniae D39 wild-type grown in M17 medium + 0.5 % (w/v) Galactose (GaM17) to grown in M17 medium + 0.5 % (w/v) Glucose (GM17).