RNA-guided programmable cytosine and adenine base editors are a powerful class of genome editing tool for the introduction of localized base transitions without generating a double-stranded DNA break. Base editors (BE) have an optimal window of activity relative to the PAM recognized by the Cas9 enzyme and these constructs are strand selective. Here we demonstrate that fusion of a programmable DNA-binding domain (pDBD) or another Cas9 orthologue to spCas9-BE, we can produce an RNA-programmable Cas9-BE-pDBD chimera or Cas9-BE-Cas9 chimeras with dramatically improved activities and increased targeting range. Cas9-pDBD or Cas9-Cas9 fusion base editors display an expanded targeting repertoire and achieve highly specific genome editing, which can be tailored to achieve extremely precise genome editing at nearly any genomic locus.

Compositions and methods comprising novel deaminase polypeptides for targeted editing of nucleic acids are provided. Compositions comprise deaminase polypeptides. Also provided are fusion proteins comprising a DNA-binding polypeptide and a deaminase of the invention. The fusion proteins include RNA-guided nucleases fused to deaminases, optionally in complex with guide RNAs. Compositions also include nucleic acid molecules encoding the deaminases or the fusion proteins. Vectors and host cells comprising the nucleic acid molecules encoding the deaminases or the fusion proteins are also provided.

Object: To provide an antisense guide RNA for editing a target RNA by ADAR.

Solution: An antisense guide RNA for editing a target RNA by ADAR, containing at least one functional region and an antisense region that is complementary to a portion of the target RNA and can form a double strand with the target RNA, in which the at least one functional region is linked to the antisense region, and in which the guide RNA does not substantially contain an ADAR-recruiting base sequence.

Compositions and methods comprising novel deaminase polypeptides for targeted editing of nucleic acids are provided. Compositions comprise deaminase polypeptides. Also provided are fusion proteins comprising a DNA-binding polypeptide and a deaminase of the invention. The fusion proteins include RNA-guided nucleases fused to deaminases, optionally in complex with guide RNAs. Compositions also include nucleic acid molecules encoding the deaminases or the fusion proteins. Vectors and host cells comprising the nucleic acid molecules encoding the deaminases or the fusion proteins are also provided.

The present disclosure relates to nucleobase editors and methods of use thereof. Disclosed herein are fusion proteins, systems, and compositions for editing disease-associated mutations and methods of use thereof. In some aspects, disclosed herein is a fusion protein comprising a Cas9 nickase and a nucleotide deaminase, wherein the Cas9 nickase comprises a first amino acid substitution at a position selected from the group consisting of 262, 324, 409, 480, 543, 694, and 1219 when compared to SEQ ID NO: 11, and wherein the Cas9 nickase comprises a second amino acid substitution at a position selected from the group consisting of 1111, 1135, 1218, 1219, 1322, 1335, and 1337 when compared to SEQ ID NO: 11.

The present invention relates to a cytosine base-editing composition, and more specifically, to a cytosine base-editing composition comprising adenine deaminase and CRISPR-associated protein 9 (Cas9), or functional analogs thereof, which has a narrow editing window and thus is capable of accurately editing cytosine in a target sequence with another base.

The present inventors have discovered that the application of the cytosine base-editing composition comprising adenine deaminase and Cas9, or functional analogs thereof, to a target sequence, causes cytosine on a specific motif to be substituted with another base, and that existing adenine base editors (ABEs) are capable of editing not only adenine but also cytosine, and can also have said substitutions occur with higher accuracy compared to existing cytosine base editors (CBEs). Thus, the cytosine base-editing composition according to the present invention is expected to be advantageously used in the treatment of genetic disorders and in research on genetic disorders.

The current disclosure relates to methods, compositions and kits for detecting modified adenosine in a target RNA molecule. Aspects relate to a method for detecting modified adenosine in a target ribonucleic acid (RNA) comprising contacting the target RNA with an adenosine deaminase enzyme (adenosine deaminase, RNA-specific) to generate a target RNA with deaminated adenosines and sequencing the target RNA with deaminated adenosines; wherein the modified adenosine is detected when the nucleotide sequence is adenosine.

The present invention relates to a fusion protein for enhancing gene editing and use thereof. In particular, the invention provides an enhanced fusion protein. The enhanced fusion proteins of the present invention can significantly increase gene editing efficiency in vivo or in vitro as compared to the wildtype gene editing protein.

The invention relates to peptide linkers and fusion proteins comprising linkers designed for optimizing the activity of the proteins comprised therein, and methods for using the same. The invention further relates to newly designed Cas12a-based adenine base editors.

The invention relates to peptide linkers and fusion proteins comprising linkers designed for optimizing the activity of the proteins comprised therein, and methods for using the same. The invention further relates to newly designed Cas12a-based adenine base editors.