The object of the present invention is to, by analyzing PPR proteins that act to bind to DNA with a prediction that RNA recognition rules of PPR motifs can also be used for recognition of DNA, find a PPR protein showing such a characteristic. According to the present invention, it was revealed that, with a protein that can bind in a DNA base-selective manner or a DNA base sequence-specific manner, which contains one or more, preferably 2 to 30, more preferably 5 to 25, most preferably 9 to 15, of PPR motifs having a structure of the following formula 1 (wherein, in the formula 1, Helix A is a part that can form an α-helix structure; X does not exist, or is a part consisting of 1 to 9 amino acids; Helix B is a part that can form an α-helix structure; and L is a part consisting of 2 to 7 amino acids), and having a specific combination of amino acids corresponding to a DNA base or DNA base sequence as amino acids of three positions of No. 1 A.A., No. 4 A.A., in Helix A of the formula 1 and No. “ii” (-2) A.A. contained in L of the formula 1, the aforementioned object could be achieved.

(Helix A)-X-(Helix B)-L  (Formula 1)

The present invention relates to a nucleic acid molecule encoding (I) a polypeptide having the activity of an endonuclease, which is (a) a nucleic acid molecule encoding a polypeptide comprising or consisting of the amino acid sequence of SEQ ID NO: 1; (b) a nucleic acid molecule comprising or consisting of the nucleotide sequence of SEQ ID NO: 2; (c) a nucleic acid molecule encoding an endonuclease, the amino acid sequence of which is at least 70% identical to the amino acid sequence of SEQ ID NO: 1; (d) a nucleic acid molecule comprising or consisting of a nucleotide sequence which is at least 50% identical to the nucleotide sequence of SEQ ID NO: 2; (e) a nucleic acid molecule which is degenerate with respect to the nucleic acid molecule of (d); or (f) a nucleic acid molecule corresponding to the nucleic acid molecule of any one of (a) to (e) wherein T is replaced by U; (II) a fragment of the polypeptide of (I) having the activity of an endonuclease. Also, the present invention relates to a vector comprising the nucleic acid molecule and a protein encoded by said nucleic acid molecule. Further, the invention relates to a method of modifying the genome of a eukaryotic cell and a method of producing a non-human vertebrate or mammal.

Described herein are engineered nucleases specific for PD1 gene target sites, the nucleases comprising mutations in the cleavage domain (e.g., FokI or homologue thereof) and/or DNA binding domain (zinc finger protein, TALE, single guide RNA) such that on-target specificity for PD1 gene target sites is increased.

Disclosed herein are engineered cleavage half-domains; fusion polypeptides comprising these engineered cleavage half-domains; polynucleotides encoding the engineered cleavage half-domains and fusion proteins; and cells comprising said polynucleotides and/or fusion proteins. Also described are methods of using these polypeptides and polynucleotides, for example for targeted cleavage of a genomic sequence.

Methods and compositions are provided for engineering mutant enzymes with reduced star activity where the mutant enzymes have a fidelity index (FI) in a specified buffer that is greater than the FI of the non-mutated enzyme in the same buffer.

The present invention provides RNA-guided endonucleases, which are engineered for expression in eukaryotic cells or embryos, and methods of using the RNA-guided endonuclease for targeted genome modification in in eukaryotic cells or embryos. Also provided are fusion proteins, wherein each fusion protein comprises a CRISPR/Cas-like protein or fragment thereof and an effector domain. The effector domain can be a cleavage domain, an epigenetic modification domain, a transcriptional activation domain, or a transcriptional repressor domain. Also provided are methods for using the fusion proteins to modify a chromosomal sequence or regulate expression of a chromosomal sequence.

Many studies have shown that CRISPR-Cas nucleases can tolerate up to five mismatches and still cleave; it is hard to predict the effects of any given single or combination of mismatches on activity. Taken together, these nucleases can show significant off-target effects but it can be challenging to predict these sites. Described herein are methods for increasing the specificity of genome editing using the CRISPR/Cas system, e.g., using RNA-guided FokI Nucleases (RFNs), e.g., FokI-Cas9 or FokI-dCas9-based fusion proteins.

One aspect of this disclosure relates to a composition of matter. The composition of matter comprises a nucleotide construct encoding a peptide. The peptide includes at least a targeting domain configured to bind to chromatin having a pattern of reduced epigenetic repression, and a DNA strand break inducing domain. When accumulated through binding at chromatin sites, the strand break inducing domain may cause specific, double-strand breaks to the DNA, inducing cell death in cells exhibiting the pattern of reduced epigenetic repression.

A clustered regularly interspaced short palindromic repeat (CRISPR)-associated complex for adaptive antiviral defence (Cascade); the Cascade protein complex comprising at least CRISPR-associated protein subunits Cas7, Cas5 and Cash which includes at least one subunit with an additional amino acid sequence possessing nucleic acid or chromatin modifying, visualising, transcription activating or transcription repressing activity. The Cascade complex with additional activity is combined with an RNA molecule to produce a ribonucleoprotein complex. The RNA molecule is selected to have substantial complementarity to a target sequence. Targeted ribonucleoproteins can be used as genetic engineering tools for precise cutting of nucleic acids in homologous recombination, non-homologous end joining, gene modification, gene integration, mutation repair or for their visualisation, transcriptional activation or repression. A pair of ribonucleotides fused to FokI dimers may be used to generate double-strand breakages in the DNA to facilitate these applications in a sequence-specific manner.

The present disclosure provides a non-naturally occurring CRISPR-Cas system comprising: a Cas9 effector protein capable of generating cohesive ends (stiCas9), and a guide polynucleotide that forms a complex with the stiCas9 and comprising a guide sequence, wherein the guide sequence hybridizes with a target sequence in a eukaryotic cell but does not hybridize to a sequence in a bacterial cell, and wherein the complex does not occur in nature. The present disclosure also provides a method of introducing a sequence of interest into a chromosome of a cell. Finally, the present disclosure provides for a method of modifying one or more nucleotides using seamless mutagenesis.