DNA-guided genome editing using the Natronobacterium gregoryi Argonaute

The RNA-guided endonuclease Cas9 has made genome editing a widely accessible technique. Similar to Cas9, endonucleases from the Argonaute protein family also use oligonucleotides as guides to degrade invasive genomes. Here we report that the Natronobacterium gregoryi Argonaute (NgAgo) is a DNA-guided endonuclease suitable for genome editing in human cells. NgAgo binds 5' phosphorylated single-stranded guide DNA (gDNA) of ∼24 nucleotides, efficiently creates site-specific DNA double-strand breaks when loaded with the gDNA. The NgAgo-gDNA system does not require a protospacer-adjacent motif (PAM), as does Cas9, and preliminary characterization suggests a low tolerance to guide-target mismatches and high efficiency in editing (G+C)-rich genomic targets.