| CPC C12N 15/11 (2013.01) [C12N 9/22 (2013.01); C12N 15/907 (2013.01); C12N 2310/20 (2017.05); C12N 2800/80 (2013.01)] | 26 Claims |
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1. A Clustered Regularly Interspaced Short Palindromic Repeat (CRISPR)-Cas system, comprising:
(1) an RNA guide sequence comprising a spacer sequence capable of hybridizing to a target RNA, and a direct repeat (DR) sequence 3′ to the spacer sequence, wherein the spacer sequence is between 25-50 nucleotides, wherein the DR sequence is an RNA sequence encoded by and corresponding to the full-length of the reverse complement sequence of SEQ ID NO: 8; and,
(2) a functional fragment of a CRISPR-associated protein (Cas), wherein said Cas has the amino acid sequence of SEQ ID NO: 1, wherein said functional fragment has an N-terminal deletion of no more than 210 residues, and a C-terminal deletion of no more than 180 residues, wherein the N-terminal deletion and C-terminal deletion result in the loss of RxxxxH motifs at both ends of the Cas having the amino acid sequence of SEQ ID NO: 1, wherein said functional fragment has completely or partially lost guide RNA-activated RNase catalytic activity compared to the guide RNA-activated RNase catalytic activity of said Cas having the amino acid sequence of SEQ ID NO: 1, and wherein said functional fragment is capable of (i) binding to the RNA guide sequence and (ii) targeting the target RNA.
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