Protected guide rnas (pgrnas)

Abstract

The invention provides for systems, methods, and compositions for altering expression of target gene sequences and related gene products. Provided are structural information on the Cas protein of the CRISPR-Cas system, use of this information in generating modified components of the CRISPR complex, vectors and vector systems which encode one or more components or modified components of a CRISPR complex, as well as methods for the design and use of such vectors and components. Also provided are methods of directing CRISPR complex formation in eukaryotic cells and methods for utilizing the CRISPR-Cas system. In particular the present invention comprehends optimized functional CRISPR-Cas enzyme systems, wherein the guide sequence is modified by secondary structure to increase the specificity of the CRISPR-Cas system and whereby the secondary structure can protect against exonuclease activity and allow for 5′ additions to the guide sequence.

Dependencies are inferred from the claim text.