The present disclosure relates, according to some embodiments, to compositions, methods, systems, and kits for programmable endonucleolytic cleavage of DNA (e.g., ds DNA). For example, the in vitro activity of an Argonaute (e.g., a mesophilic Argonaute CbAgo from Clostridium butyricum) may be synchronized with DNA strand unwinding activity of a helicase (e.g., a nuclease deficient RecB.sup.exo-C DNA helicase from E. coli) for a rapid and efficient cleavage of double-stranded DNA targets. Enzymatic properties of CbAgo and different aspects of ds DNA cleavage were thoroughly explored by adapting high-throughput capillary electrophoreses technique for monitoring CbAgo cleavage activity in concurrence with RecB.sup.exo-C. The present disclosure shows that in the presence of RecB.sup.exo-C, CbAgo can be programmed with guides to cleave any site of interest localized at up to 10 kb distance from the end of linear ds DNA at 37° C. temperature. CbAgo/RecB.sup.exo-C can be programmed to generate DNA fragments flanked with unique single-stranded extensions suitable for seamless ligation with compatible DNA fragments. The present disclosure relates further the compositions, methods, systems, and kits for PRC-free assembly of linear DNA molecules by using CbAgo/RecB.sup.exo-C programmable DNA endonuclease. The results presented here demonstrate that the combination of CbAgo and RecB.sup.exo-C is currently an efficient mesophilic DNA-guided DNA-cleaving programmable endonuclease which can be used to prepare synthetic biology tools that require or benefit from sequence-specific nicking/cleavage of natural DNA at otherwise inaccessible locations.

The present disclosure provides for systems, methods, and compositions for targeting nucleic acids. In particular, the invention provides novel class 1, Type IV and novel class I, Type I Cas proteins and their use in modifying target sequences.

A peptide is disclosed that has an amino acid sequence selected from X.sub.1-X.sub.2-X.sub.3-Gln-Leu-Met-Leu-Cys-Val-Leu-X.sub.4-X.sub.5-X.sub.6 (SEQ ID NO: 3), X.sub.1-X.sub.2-X.sub.3-Gln-X.sub.7-Met-X.sub.10-Cys-Val-X.sub.11-X.sub.4-X.sub.5-X.sub.6 (SEQ ID NO: 4), Ile-Ser-Phe-Gln-Leu-Met-Leu (SEQ ID NO: 5), Leu-Cys-Val-Leu-Asp-Tyr-Phe (SEQ ID NO: 6), X.sub.1-X.sub.2-X.sub.3-Gln-Leu-X.sub.8-Leu-X.sub.9-Val-Leu-X.sub.4-X.sub.5-X.sub.6 (SEQ ID NO: 7), X.sub.1-X.sub.2-X.sub.3-Gln-Leu-X.sub.8-Leu-X.sub.9-Val-Leu-X.sub.4-X.sub.5-X.sub.6 (SEQ ID NO: 7), X.sub.1-X.sub.2-X.sub.3-X.sub.12-Leu-Met-Leu-Cys-X.sub.13-Leu-X.sub.4-X.sub.5-X.sub.6 (SEQ ID NO: 10), Gln-X.sub.7-Met-X.sub.10-Cys-Val-X.sub.11 (SEQ ID NO: 11), Gln-Leu-X.sub.8-Leu-X.sub.9-Val-Leu (SEQ ID NO: 12), X.sub.12-Leu-Met-Leu-Cys-X.sub.13-Leu (SEQ ID NO: 13), Asp-Leu-Val-Ile-Ser-Phe-Gln-Leu-Met-Leu-Cys-Val-Leu-Asp-Tyr-Phe-Ile-Lys (SEQ ID NO: 14) and retro-inverso peptides thereof. The peptides disclosed herein may be used to treat liver cancer, lung cancer, breast cancer, pancreatic cancer, or brain cancer.

Clean version of Abstract Small interfering RNA (siRNA) for inhibiting the expression of the mini-chromosome maintenance 7 (MCM7) gene, and a composition and use thereof are provided. The siRNA designed and verified by the present disclosure can effectively inhibit the expression of the MCM7 gene, and thus inhibit the DNA synthesis, cell proliferation, and colony formation of cancer cells, thereby achieving the purpose of preventing and treating a tumor. The present disclosure provides a new target and candidate compound for cancer prevention or treatment.

Conformationally-constrained helicases having improved activity and strength are provided. Methods of making conformationally-constrained helicases having improved activity and strength are provided. Methods of using conformationally-constrained helicases having improved activity and strength are provided. The present invention is based on the discovery of novel modified helicases that show dramatically enhanced helicase activity and increased strength as compared to unmodified helicases. As described further herein, it has been surprisingly discovered that, by controlling the conformation of certain subdomains such that the helicase remains in a closed form (e.g., by covalently crosslinking the 2B domain to the 1A domain or the 1B domain in a Rep helicase), a highly active and strong form of the helicase is achieved

Method for characterising a double stranded nucleic acid using a nano-pore and anchor molecules at both ends of said nucleic acid.

Provided are compositions, methods, and kits for improving CRISPR-based editing of DNA targets by a CRISPR-associated (Cas) enzyme. The improvement is made by combining the Cas enzyme and a CRISPR targeting RNA a heterologous DNA repair enzyme that is at least one of RecBCD, AddAB, or AdnAB. The heterologous DNA repair enzyme may have inactivated nuclease activity. The method can include using a DNA repair template to introduce one or more changes into the edited DNA. Cells that contain components of the improved CRISPR systems are included, as are kits for making such cells.

The invention relates to a new method of characterising FIG. 3 a target RNA polynucleotide by taking one or more measurements as the target RNA polynucleotide moves with respect to a transmembrane pore. The movement is controlled by a DNA helicase. The invention also relates to a modified RNA construct wherein the RNA polynucleotide has been modified to increase DNA helicase binding thereto.

The invention relates to a new method of characterising a target RNA polynucleotide by taking one or more measurements as the target RNA polynucleotide moves with respect to a transmembrane pore. The movement is controlled by a DNA helicase. The invention also relates to a modified RNA construct wherein the RNA polynucleotide has been modified to increase DNA helicase binding thereto.

Conformationally-constrained helicases having improved activity and strength are provided. Methods of making conformationally-constrained helicases having improved activity and strength are provided. Methods of using conformationally-constrained helicases having improved activity and strength are provided. The present invention is based on the discovery of novel modified helicases that show dramatically enhanced helicase activity and increased strength as compared to unmodified helicases. As described further herein, it has been surprisingly discovered that, by controlling the conformation of certain subdomains such that the helicase remains in a closed form (e.g., by covalently crosslinking the 2B domain to the 1A domain or the 1B domain in a Rep helicase), a highly active and strong form of the helicase is achieved.