Specificity and sensitivity of an RNA targeting type III CRISPR complex coupled with a NucC endonuclease effector.
Nucleic Acids Res
; 49(22): 13122-13134, 2021 12 16.
Article
in English
| MEDLINE | ID: covidwho-1555464
Preprint
This scientific journal article is probably based on a previously available preprint. It has been identified through a machine matching algorithm, human confirmation is still pending.
See preprint
This scientific journal article is probably based on a previously available preprint. It has been identified through a machine matching algorithm, human confirmation is still pending.
See preprint
ABSTRACT
Type III CRISPR systems detect invading RNA, resulting in the activation of the enzymatic Cas10 subunit. The Cas10 cyclase domain generates cyclic oligoadenylate (cOA) second messenger molecules, activating a variety of effector nucleases that degrade nucleic acids to provide immunity. The prophage-encoded Vibrio metoecus type III-B (VmeCmr) locus is uncharacterised, lacks the HD nuclease domain in Cas10 and encodes a NucC DNA nuclease effector that is also found associated with Cyclic-oligonucleotide-based anti-phage signalling systems (CBASS). Here we demonstrate that VmeCmr is activated by target RNA binding, generating cyclic-triadenylate (cA3) to stimulate a robust NucC-mediated DNase activity. The specificity of VmeCmr is probed, revealing the importance of specific nucleotide positions in segment 1 of the RNA duplex and the protospacer flanking sequence (PFS). We harness this programmable system to demonstrate the potential for a highly specific and sensitive assay for detection of the SARS-CoV-2 virus RNA with a limit of detection (LoD) of 2 fM using a commercial plate reader without any extrinsic amplification step. The sensitivity is highly dependent on the guide RNA used, suggesting that target RNA secondary structure plays an important role that may also be relevant in vivo.
Full text:
Available
Collection:
International databases
Database:
MEDLINE
Main subject:
RNA, Viral
/
Endodeoxyribonucleases
/
Endoribonucleases
/
CRISPR-Associated Proteins
/
CRISPR-Cas Systems
/
SARS-CoV-2
Type of study:
Diagnostic study
/
Experimental Studies
Limits:
Animals
/
Humans
Language:
English
Journal:
Nucleic Acids Res
Year:
2021
Document Type:
Article
Affiliation country:
Nar
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