Streptococcus pneumoniae Tigr4
Ontology highlight
ABSTRACT:
PROVIDER: PRJNA76613 | ENA |
REPOSITORIES: ENA
Dataset's files
| Action | DRS | |||
|---|---|---|---|---|
| Other | ||||
| SRR364145_1.fastq.gz | Fastqsanger.gz | |||
| SRR364145_2.fastq.gz | Fastqsanger.gz | |||
| SRR364146_1.fastq.gz | Fastqsanger.gz | |||
| SRR364146_2.fastq.gz | Fastqsanger.gz |
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Project description:Although the pili of Gram-positive bacteria are putative virulence factors, little is known about their structure. Here we describe the molecular architecture of pilus-1 of Streptococcus pneumoniae, which is a major cause of morbidity and mortality worldwide. One major (RrgB) and two minor components (RrgA and RrgC) assemble into the pilus. Results from TEM and scanning transmission EM show that the native pili are approximately 6 nm wide, flexible filaments that can be over 1 microm long. They are formed by a single string of RrgB monomers and have a polarity defined by nose-like protrusions. These protrusions correlate to the shape of monomeric RrgB-His, which like RrgA-His and RrgC-His has an elongated, multi-domain structure. RrgA and RrgC are only present at the opposite ends of the pilus shaft, compatible with their putative roles as adhesin and anchor to the cell wall surface, respectively. Our structural analyses provide the first direct experimental evidence that the native S. pneumoniae pilus shaft is composed exclusively of covalently linked monomeric RrgB subunits oriented head-to-tail.
| S-EPMC2797065 | biostudies-literature
Project description:The objective of the study is to obtain a high resolution transcription map of S. pneumoniae genome and make it available through a genome browser. The study also help to identify gene expression pattern, presence of small RNAs, Antisense expression and operon structure.
2009-02-10 | GSE12636 | GEO
Project description:Streptococcus pneumoniae TIGR4 Genome sequencing
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Project description:Streptococcus pneumoniae TIGR4 Genome sequencing
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Project description:Streptococcus pneumoniae TIGR4 Raw sequence reads
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Project description:Streptococcus pneumoniae (pneumococcus) is a leading human pathogen that can cause serious localized and invasive diseases. Pneumococci can undergo a spontaneous and reversible phase variation that is reflected in colony opacity and which allows the population to adapt to different host environments. Generally, transparent variants are adapted for nasopharyngeal colonization, whereas opaque variants are associated with invasive disease. In recent work, colony phase variation was shown to occur by means of recombination events to generate multiple alleles of the hsdS targeting domain of a DNA methylase complex, which mediates epigenetic changes in gene expression. A panel of isogenic strains were created in the well-studied S. pneumoniae TIGR4 background that are "locked" in the transparent (n = 4) or opaque (n = 2) colony phenotype. The strains had significant differences in colony size which were stable over multiple passages in vitro and in vivo. While there were no significant differences in adherence for the phase-locked mutant strains to immortalized epithelial cells, biofilm formation and viability were reduced for the opaque variants in static assays. Nasopharyngeal colonization was stable for all strains, but the mortality rates differed between them. Transcript profiling by transcriptome sequencing (RNA-seq) analyses revealed that the expression levels of certain virulence factors were increased in a phase-specific manner. As epigenetic regulation of phase variation (often referred to as "phasevarion") is emerging as a common theme for mucosal pathogens, these results serve as a model for future studies of host-pathogen interactions. IMPORTANCE A growing number of bacterial species undergo epigenetic phase variation due to variable expression or specificity of DNA-modifying enzymes. For pneumococci, this phase variation has long been appreciated as being revealed by changes in colony opacity, which are reflected in changes in expression or accessibility of factors on the bacterial surface. Recent work showed that recombination-generated variation in alleles of the HsdS DNA methylase specificity subunit mediated pneumococcal phase variation. We generated phase-locked populations of S. pneumoniae TIGR4 expressing a single nonvariant hsdS allele and observed significant differences in gene expression and virulence. These results highlight the importance of focused pathogenesis studies within specific phase types. Moreover, the generation of single-allele hsdS constructs will greatly facilitate such studies.
| S-EPMC5687919 | biostudies-literature
Project description:Streptococcus pneumoniae (Sp) strain TIGR4 is a virulent, encapsulated serotype that causes bacteremia, otitis media, meningitis and pneumonia. Increased bacterial resistance and limited efficacy of the available vaccine to some serotypes complicate the treatment of diseases associated to this microorganism. Flavodoxins are bacterial proteins involved in several important metabolic pathways. The Sp flavodoxin (Spfld) gene was recently reported to be essential for the establishment of meningitis in a rat model, which makes SpFld a potential drug target. To facilitate future pharmacological studies, we have cloned and expressed SpFld in E. coli and we have performed an extensive structural and biochemical characterization of both the apo form and its active complex with the FMN cofactor. SpFld is a short-chain flavodoxin containing 146 residues. Unlike the well-characterized long-chain apoflavodoxins, the Sp apoprotein displays a simple two-state thermal unfolding equilibrium and binds FMN with moderate affinity. The X-ray structures of the apo and holo forms of SpFld differ at the FMN binding site, where substantial rearrangement of residues at the 91-100 loop occurs to permit cofactor binding. This work will set up the basis for future studies aiming at discovering new potential drugs to treat S. pneumoniae diseases through the inhibition of SpFld.
| S-EPMC5029806 | biostudies-literature
Project description:Purpose: We recently reported that isogenic deletion of lysine decarboxylase (ΔcadA/SP_0916), an enzyme that catalyzes the biosynthesis of polyamine cadaverine in Streptococcus pneumoniae TIGR4 results in loss of capsular polysaccharide (CPS), which constitutes a novel mechanism of regulation of CPS. Here, we conducted RNA-Seq to elucidate molecular mechanisms of CPS regulation in polyamine synthesis impaired pneumococci. Result: Significantly differentially expressed genes in ΔcadA represent pneumococcal pathways involved in the biosynthesis of precursors for CPS and peptidoglycan. Conclusion: We establish a possible link and interchange between two cellular processes such as high energy demanding capsule production and oxidative stress responses in polyamine synthesis impaired pneumococci (ΔcadA).
2019-09-30 | GSE130511 | GEO
Project description:The objective of the study is to obtain a high resolution transcription map of S. pneumoniae genome and make it available through a genome browser. The study also help to identify gene expression pattern, presence of small RNAs, Antisense expression and operon structure. S. pneumoniae strain TIGR4 (ref) was grown in THYmedium, Todd-Hewitt broth supplemented with 0.5% yeast extract. Cells were harvested from duplicate cultures from mid-log phase (OD600 nm, 0.4â0.6) of growth by centrifugation. The harvested pellets were washed twice in sterile PBS (pH 7.0) and stored at -80°C. RNA was purified from frozen bacterial pellets using Qiagen RNeasy kit by following the manufacturerâs protocol. Isolated RNA was treated with DNase to remove genomic DNA contamination, and purity was checked by performing a one-step RT-PCR using primers specific for 16S rRNA in presence or absence of reverse transcriptase. RNA concentration and quality were determined by using Agilent Bioanalyzer. Purified RNA was stored in nuclease free water at -80°C. One microgram of total RNA was used by Nimblegen systems for labeling and hybridization. 2 biological replicates (single colored) were used in the analysis. 20,000 random probes were designed on the chip as a negative controls to measure non-specific hybridization. 35 genes identified through proteomics of same sample were used as positive controls.
2010-05-06 | E-GEOD-12636 | biostudies-arrayexpress
Project description:Transcriptional Characterization of Streptococcus pneumoniae Interacting with Human Pharyngeal Cells
| PRJNA192825 | ENA