2.50
Hdl Handle:
http://hdl.handle.net/10033/301904
Title:
The tracrRNA and Cas9 families of type II CRISPR-Cas immunity systems.
Authors:
Chylinski, Krzysztof; Le Rhun, Anaïs; Charpentier, Emmanuelle
Abstract:
CRISPR-Cas is a rapidly evolving RNA-mediated adaptive immune system that protects bacteria and archaea against mobile genetic elements. The system relies on the activity of short mature CRISPR RNAs (crRNAs) that guide Cas protein(s) to silence invading nucleic acids. A set of CRISPR-Cas, type II, requires a trans-activating small RNA, tracrRNA, for maturation of precursor crRNA (pre-crRNA) and interference with invading sequences. Following co-processing of tracrRNA and pre-crRNA by RNase III, dual-tracrRNA:crRNA guides the CRISPR-associated endonuclease Cas9 (Csn1) to cleave site-specifically cognate target DNA. Here, we screened available genomes for type II CRISPR-Cas loci by searching for Cas9 orthologs. We analyzed 75 representative loci, and for 56 of them we predicted novel tracrRNA orthologs. Our analysis demonstrates a high diversity in cas operon architecture and position of the tracrRNA gene within CRISPR-Cas loci. We observed a correlation between locus heterogeneity and Cas9 sequence diversity, resulting in the identification of various type II CRISPR-Cas subgroups. We validated the expression and co-processing of predicted tracrRNAs and pre-crRNAs by RNA sequencing in five bacterial species. This study reveals tracrRNA family as an atypical, small RNA family with no obvious conservation of structure, sequence or localization within type II CRISPR-Cas loci. The tracrRNA family is however characterized by the conserved feature to base-pair to cognate pre-crRNA repeats, an essential function for crRNA maturation and DNA silencing by dual-RNA:Cas9. The large panel of tracrRNA and Cas9 ortholog sequences should constitute a useful database to improve the design of RNA-programmable Cas9 as genome editing tool.
Affiliation:
The Laboratory for Molecular Infection Medicine Sweden (MIMS), Umeå Centre for Microbial Research (UCMR), Department of Molecular Biology, Umeå University, Umeå, Sweden.
Citation:
The tracrRNA and Cas9 families of type II CRISPR-Cas immunity systems. 2013, 10 (5):726-37 RNA Biol
Journal:
RNA biology
Issue Date:
May-2013
URI:
http://hdl.handle.net/10033/301904
DOI:
10.4161/rna.24321
PubMed ID:
23563642
Type:
Article
Language:
en
ISSN:
1555-8584
Appears in Collections:
publications of the department Regulation of infection

Full metadata record

DC FieldValue Language
dc.contributor.authorChylinski, Krzysztofen_GB
dc.contributor.authorLe Rhun, Anaïsen_GB
dc.contributor.authorCharpentier, Emmanuelleen_GB
dc.date.accessioned2013-09-19T12:22:33Z-
dc.date.available2013-09-19T12:22:33Z-
dc.date.issued2013-05-
dc.identifier.citationThe tracrRNA and Cas9 families of type II CRISPR-Cas immunity systems. 2013, 10 (5):726-37 RNA Biolen_GB
dc.identifier.issn1555-8584-
dc.identifier.pmid23563642-
dc.identifier.doi10.4161/rna.24321-
dc.identifier.urihttp://hdl.handle.net/10033/301904-
dc.description.abstractCRISPR-Cas is a rapidly evolving RNA-mediated adaptive immune system that protects bacteria and archaea against mobile genetic elements. The system relies on the activity of short mature CRISPR RNAs (crRNAs) that guide Cas protein(s) to silence invading nucleic acids. A set of CRISPR-Cas, type II, requires a trans-activating small RNA, tracrRNA, for maturation of precursor crRNA (pre-crRNA) and interference with invading sequences. Following co-processing of tracrRNA and pre-crRNA by RNase III, dual-tracrRNA:crRNA guides the CRISPR-associated endonuclease Cas9 (Csn1) to cleave site-specifically cognate target DNA. Here, we screened available genomes for type II CRISPR-Cas loci by searching for Cas9 orthologs. We analyzed 75 representative loci, and for 56 of them we predicted novel tracrRNA orthologs. Our analysis demonstrates a high diversity in cas operon architecture and position of the tracrRNA gene within CRISPR-Cas loci. We observed a correlation between locus heterogeneity and Cas9 sequence diversity, resulting in the identification of various type II CRISPR-Cas subgroups. We validated the expression and co-processing of predicted tracrRNAs and pre-crRNAs by RNA sequencing in five bacterial species. This study reveals tracrRNA family as an atypical, small RNA family with no obvious conservation of structure, sequence or localization within type II CRISPR-Cas loci. The tracrRNA family is however characterized by the conserved feature to base-pair to cognate pre-crRNA repeats, an essential function for crRNA maturation and DNA silencing by dual-RNA:Cas9. The large panel of tracrRNA and Cas9 ortholog sequences should constitute a useful database to improve the design of RNA-programmable Cas9 as genome editing tool.en_GB
dc.language.isoenen
dc.rightsArchived with thanks to RNA biologyen_GB
dc.titleThe tracrRNA and Cas9 families of type II CRISPR-Cas immunity systems.en
dc.typeArticleen
dc.contributor.departmentThe Laboratory for Molecular Infection Medicine Sweden (MIMS), Umeå Centre for Microbial Research (UCMR), Department of Molecular Biology, Umeå University, Umeå, Sweden.en_GB
dc.identifier.journalRNA biologyen_GB

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