Ontology highlight
ABSTRACT:
PROVIDER: PRJNA539885 | ENA |
REPOSITORIES: ENA
Dataset's files
| Action | DRS | |||
|---|---|---|---|---|
| SRR8962120_1.fastq.gz | Fastqsanger.gz | |||
| SRR8962120_2.fastq.gz | Fastqsanger.gz | |||
| SRR8962130_1.fastq.gz | Fastqsanger.gz | |||
| SRR8962130_2.fastq.gz | Fastqsanger.gz | |||
| SRR8962140_1.fastq.gz | Fastqsanger.gz |
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Similar Datasets
Project description:Transcriptome sequencing was carried out on an Illumina HiSeq platform to investigate the activation of CRISPR-Cas and DNA repair systems by Csa3a in Sulfolobus islandicus Rey15A. We compared the differently expressed genes in Sulfolobus islandicus Rey15A strain with csa3a overexpression vs. Sulfolobus islandicus Rey15A strain carrying an empty expression vector, cas1 deletion strain with csa3a overexpression vs. cas1 deletion strain carrying an empty expression vector, as well as interference-deficient strain with csa3a overexpression vs. interference-deficient strain carrying an empty expression vector. We find that cas genes (SiRe_0760, SiRe_0761, SiRe_0762, SiRe_0763), nucleotidyltransferase domain of DNA polymerase beta (SiRe_0459), chromosome segregation protein (SMC)-related ATPase (SiRe_0649), SMC-related protein (SiRe_1142) and three HerA helicases involved in DNA double break repair (encoded by SiRe_0064 and SiRe_0095 of nurA-herA operons, and SiRe_1857) were significantly up-regulated. Our data indicated that the Csa3a regulator couples transcriptional activation of spacer acquisition genes, CRISPR RNA transcription, DNA repair and genome stability genes.
2017-10-31 | GSE99099 | GEO
Project description:Key to CRISPR-Cas adaptive immunity is maintaining an ongoing record of invading nucleic acids that are encountered, a process carried out by the Cas1-Cas2 complex that integrates short segments of foreign genetic material (spacers) into the CRISPR locus. It is hypothesized that Cas1 evolved from casposases, a novel class of transposases. We show here that casposase integration in vitro recapitulates several properties of CRISPR-Cas integrases. The X-ray structure of Methanosarcina mazei casposase bound to DNA representing the product of integration reveals a tetramer with target DNA bound snugly between two dimers in which single-stranded casposon end binding resembles that of spacer 3'-overhangs. The differences between transposase and CRISPR-Cas integrase are largely architectural, and it appears that evolutionary change involved changes in protein-protein interactions to favor Cas2 binding over tetramerization and the separation of Cas1 dimers. This, in turn, led to preferred integration of single spacers over two transposon ends.
2020-02-03 | GSE139037 | GEO
Project description:A whole transcriptome study was performed on Sulfolobus islandicus REY15A actively undergoing CRISPR spacer acquisition from the crenarchaeal monocaudavirus STSV2 in rich (TYS) and basal (SCV) media over a 6 day period. Spacer acquisition preceded strong host growth retardation, and changes in viral transcript abundance and virus copy numbers showed significant differences between the two media. Results showed that rich medium favoured CRISPR-Cas immunity generation.
2015-12-06 | E-MTAB-4027 | biostudies-arrayexpress
Project description:CRISPR loci are found in bacterial and archaeal genomes where they provide the molecular machinery for acquisition of immunity against foreign DNA. In addition to the cas genes fundamentally required for CRISPR activity, a second class of genes is associated with the CRISPR loci, of which many have no reported function in CRISPR-mediated immunity. Here, we characterize MM_0565 of Methanosarcina mazei Gö1 associated to the type I-B CRISPR-locus providing evidence for its relevance in regulating this system. We show that MM_0565 is composed of a modified Rossmann-like fold and a winged helix-turn-helix domain and forms a dimer in solution. While direct effects on CRISPR-Cas transcription were not detected by genetic approaches, binding to the leader region of both CRISPR-Cas systems was observed by microscale thermophoresis and electromobility shift assays. Overexpression of MM_0565 however, strongly induced transcription of the cas1-solo gene located in the recently reported casposon, the gene product of which shows high similarity to classical Cas1 proteins. Based on our findings we hypothesize that Cas1-solo is involved in the adaptation of CRISPR-mediated immunity in M. mazei, and that MM_0565 modulates the activity of the CRISPR systems amongst potential other hypnotized actions by activating the transcription of the cas1-solo gene.
2020-09-08 | GSE151372 | GEO
Project description:Spacer acquisition by Type III CRISPR-Cas system during bacteriophage infection of Thermus thermophilus
| PRJNA631468 | ENA
Project description:CRISPR-Cas constitutes an adaptive prokaryotic defence system against invasive nucleic acids like viruses and plasmids. Beyond their role in immunity, CRISPR-Cas systems have been shown to closely interact with components of cellular DNA repair pathways either by regulating their expression or via direct protein-protein contact or enzymatic activity. The integrase Cas1 is usually involved in the adaptation phase of CRISPR-Cas immunity but its function in cellular DNA repair pathways has been proposed before. Here, we analysed the capacity of an archaeal Cas1 from Haloferax volcanii to compensate DNA damage induced by oxidative stress and found that a deletion of the cas1 gene led to severe growth defects after stress induction. In addition, our results indicate that Cas1 is directly involved in DNA damage repair as the enzymatically active site of the protein is crucial for growth rescue under oxidative conditions. Based on biochemical cleavage assays, we propose a mechanism in which Cas1 exerts a similar function like the DNA repair protein Fen1 by resolving branched repair intermediate structures. Overall, the present study broadens our understanding of the functional link between CRISPR-Cas immunity and DNA repair by demonstrating that Cas1 and Fen1 display commutable roles during archaeal DNA damage repair.
2022-05-20 | PXD029952 | Pride
Project description:Prokaryotes create adaptive immune memories by acquiring foreign DNA snippets, known as spacers, into the CRISPR array1. In type II CRISPR-Cas systems, the RNA-guided effector Cas9 also assists the acquisition machinery by selecting spacers from protospacer adjacent motif (PAM)-flanked DNA2,3. Here, we uncover the first biological role for Cas9 that is independent of its dual RNA partners. Following depletion of crRNA and/or tracrRNA, Neisseria apoCas9 stimulates spacer acquisition efficiency. Physiologically, Cas9 senses low levels of crRNA in cells with short CRISPR arrays – such as those undergoing array neogenesis or natural array contractions – and dynamically upregulates acquisition to quickly expand the small immune memory banks. As the CRISPR array expands, rising crRNA abundance in turn reduces apoCas9 availability, thereby dampening acquisition to mitigate autoimmunity risks associate with elevated acquisition. While apoCas9’s nuclease lobe alone suffices for stimulating acquisition, only full-length Cas9 responses to crRNA levels to boost acquisition in cells with low immunity depth. Finally, we show that this activity is evolutionarily conserved across multiple type II-C Cas9 orthologs. Altogether, we establish an auto-replenishing feedback mechanism in which apoCas9 safeguards CRISPR immunity depth by acting as both a crRNA sensor and a regulator of spacer acquisition.
2025-08-29 | GSE302092 | GEO