Some aspects of this disclosure provide strategies, systems, reagents, methods, and kits that are useful for the targeted editing of nucleic acids, including editing a single site within the genome of a cell or subject, e.g., within the human genome. In some embodiments, fusion proteins of Cas9 and nucleic acid editing enzymes or enzyme domains, e.g., deaminase domains, are provided. In some embodiments, methods for targeted nucleic acid editing are provided. In some embodiments, reagents and kits for the generation of targeted nucleic acid editing proteins, e.g., fusion proteins of Cas9 and nucleic acid editing enzymes or domains, are provided.

A method for producing 2-keto-3-deoxygluconate (KDG) from 2-(acetylamino)-2-deoxy-D-gluconic acid (GlcNAc1A) by two enzymes; GlcNAc1A is converted to KDG by incubating GlcNAc1A with a deacetylase OngB at 25° C. for 4-12 h and then with a deaminase OngC at 25° C. for another 10-15 h; it constructs two engineered E. coli/pET22b-ongB (carrying the ongB gene) and E. coli/pET22b-ongC (carrying the ongC gene) strains to prepare recombinant proteins OngB and OngC, respectively; at the action of these two enzymes, OngB and OngC, GlcNAc1A is converted to KDG, which solves the bottleneck of GlcNAc1A utilization during the bioconversion of chitin; the KDG is an important metabolic intermediate to synthesize furan derivatives, herbicides, food additives and other industrially important chemical compounds, having wide industrial applications.

Some aspects of this disclosure provide compositions, methods, systems, and kits for controlling the activity of RNA-programmable endonucleases, such as Cas9, or for controlling the activity of proteins comprising a Cas9 variant fused to a functional effector domain, such as a nuclease, nickase, recombinase, deaminase, transcriptional activator, transcriptional repressor, or epigenetic modifying domain. For example, the inventive proteins provided comprise a ligand-dependent intein, the presence of which inhibits one or more activities of the protein (e.g., gRNA binding, enzymatic activity, target DNA binding). The binding of a ligand to the intein results in self-excision of the intein, restoring the activity of the protein.

The present invention refers to a plant or plant part comprising a polynucleotide encoding a mutated TriA polypeptide, the expression of said polynucleotide confers to the plant or plant part tolerance to herbicides.

A method for modulating a methylation/demethylation state of a nucleic acid, more specifically, a method for site-removing one or more methylated bases from a genome guided by a sgRNA sequence in a cell.

Provided herein, among other things, is a method for deaminating a double-stranded nucleic acid. In some embodiments, the method may comprise contacting a double-stranded DNA substrate that comprises cytosines and a double-stranded DNA deaminase having an amino acid sequence that is at least 80% identical to any of SEQ ID NOS: 21, 40, 47, 49, 50, 55, 58, 59, 62, 63, 65, 67, 70, 71, 76, 106, 107, 110, 112, 114, 117, 163 and/or 164 to produce a deamination product that comprises deaminated cytosines. Enzymes and kits for performing the method are also provided.

Aspects of the disclosure relate to a gene therapy approach for diseases, disorders, or conditions caused by mutation in the stop codon utilizing modified tRNA. At least 10-15% of all genetic diseases, including muscular dystrophy (e.g. Duchene muscular dystrophy), some cancers, beta thalassemia, Hurler syndrome, and cystic fibrosis, fall into this category. Not to be bound by theory, it is believed that this approach is safer than CRISPR approaches due to minimal off-target effects and the lack of genome level changes.

In some aspects, the present invention provides methods and compositions for modifying target sites within nucleic acid molecules. In some embodiments, the methods comprise using adenosine deaminases that act on RNA (ADARs), and variants thereof, to modify target sites within DNA-RNA hybrid molecules. In other aspects, ADAR2 variant polypeptides as well as fusion proteins comprising an ADAR catalytic domain and a hybrid nucleic acid binding domain are provided, as are methods for use thereof. Methods for preventing and treating genetic disorders are also provided herein.

Provided herein are methods of delivering “split” Cas9 protein or nucleobase editors into a cell, e.g., via a recombinant adeno-associated vims (rAAV), to form a complete and functional Cas9 protein or nucleobase editor. The Cas9 protein or the nucleobase editor is split into two sections, each fused with one part of an intein system (e.g., intein-N and intein-C encoded by the dnaE-n and dnaE-c genes, respectively). Upon co-expression, the two sections of the Cas9 protein or nucleobase editor are ligated together via intein-mediated protein splicing. Nucleic acid molecules encoding the N-terminal portion of a Cas9 protein or a nucleobase editor fused to an intein, and nucleic acid molecules encoding the C-terminal portion of a Cas9 protein or nucleobase editor, are provided. Recombinant AAV vectors (e.g, vectors comprising one or more of these nucleic acid molecules each comprising an intein) and particles for the delivery of the split Cas9 protein or nucleobase editor, compositions comprising such AAV vectors and particles, and methods of using such rAAV vectors and particles are also provided. Methods of administering such compositions and AAV particles to a subject are further provided. Cells and compositions comprising these nucleic acid molecules rAAV vectors, and rAAV particles are also provided.

In some aspects, the present invention provides methods and compositions for modifying target sites within nucleic acid molecules. In some embodiments, the methods comprise using adenosine deaminases that act on RNA (ADARs), and variants thereof, to modify target sites within DNA-RNA hybrid molecules. In other aspects, ADAR2 variant polypeptides as well as fusion proteins comprising an ADAR catalytic domain and a hybrid nucleic acid binding domain are provided, as are methods for use thereof. Methods for preventing and treating genetic disorders are also provided herein.