The invention provides for delivery, engineering and optimization of systems, methods, and compositions for manipulation of sequences and/or activities of target sequences. Provided are delivery systems and tissues or organ which are targeted as sites for delivery. Also provided are vectors and vector systems some of which encode one or more components of a SIN CRISPR complex, as well as methods for the design and use of such vectors. Also provided are methods of directing SIN CRISPR complex formation in eukaryotic cells to ensure enhanced specificity for target recognition and avoidance of toxicity and to edit or modify a target site in a genomic locus of interest to alter or improve the status of a disease or a condition.

Engineered CRISPR-Cas9 nucleases with altered and improved PAM specificities and their use in genomic engineering, epigenomic engineering, and genome targeting.

Disclosed herein are methods and compositions for inactivating mutant genes associated with LCA, using engineered nucleases comprising a DNA binding domain and a cleavage domain or cleavage half-domain in conditions promoting the cleavage of the mutant genes. Polynucleotides encoding nucleases, vectors comprising polynucleotides encoding nucleases, and cells comprising polynucleotides encoding nucleases and/or cells comprising nucleases are also provided.

The invention is in the field of regulation of enzymatic activity in nucleic acid modifying reactions. It describes a method of regulating enzymatic activity by adding chelating agents to the reaction composition and exploits the fact that both the binding of divalent cations to these chelating agents and the pH of commonly used buffers is temperature dependent. PCR experiments that are hampered by non-specific side products can be regulated such that the target sequence is amplified in a more specific manner.

A gene editing system comprising: (a) a Type V CRISPR nuclease polypeptide or a first nucleic acid encoding the Type V CRISPR nuclease polypeptide; (b) a reverse transcriptase (RT) polypeptide or a second nucleic acid encoding the RT polypeptide; (c) a guide RNA (gRNA) or a third nucleic acid encoding the gRNA, wherein the gRNA comprises one or more binding sites recognizable by the Type V CRISPR nuclease (CRISPR nuclease binding sites) and a spacer sequence specific to a target sequence within a genomic site of interest, the target sequence being adjacent to a protospacer adjacent motif (PAM); and (d) a reverse transcription donor RNA (RT donor RNA) or a fourth nucleic acid encoding the RT donor RNA, wherein the RT donor RNA comprises a primer binding site (PBS) and a template sequence.

The invention provides improved methods for synthesizing polynucleotides, such as DNA and RNA, using renewable initiators coupled to a solid support. Using the methods of the invention, specific sequences of polynucleotides can be synthesized de novo, base by base, in an aqueous environment, without the use of a nucleic acid template.

CRISPR/CAS-related compositions and methods for altering a cell or treating a disease, for example, by gene conversion, are disclosed.

The present disclosure provides systems, compositions, and methods for simultaneously editing both strands of a double-stranded DNA sequence at a target site to be edited. In some aspects, the systems comprise a first and second prime editor complex, wherein each of the first and second prime editor complexes comprises (1) a prime editor comprising (i) a nucleic acid programmable DNA binding protein (napDNAbp), and (ii) a polypeptide having an RNA-dependent DNA polymerase activity; and (2) a pegRNA comprising a spacer sequence, gRNA core, a DNA synthesis template, and a primer binding site, wherein the DNA synthesis template encodes a desired DNA sequence or a complement thereof, wherein the desired DNA sequence and the complement thereof form a duplex comprising an edited portion which integrates into the target site to be edited. In some aspects, the systems comprise a first, second, third, and fourth prime editor complex, each comprising a prime editor and a PEgRNA. Also provided herein are methods for simultaneously editing both strands of a double-stranded DNA sequence at a target site to be edited. Further provided herein are pharmaceutical compositions, polynucleotides, vectors, cells, and kits.

Provided herein are CRIS-PR/Cas9 complexes and methods of using same.

The present invention relates to esterases, more particularly to esterase variants having improved activity and/or improved thermostability compared to the esterase of SEQ ID NO: 1 and the uses thereof for degrading polyester containing material, such as plastic products. The esterases of the invention are particularly suited to degrade polyethylene terephthalate, and material containing polyethylene terephthalate.