Fig. 1.

Molecular schematic of Cas9 and Cas12a interaction with genome target. Representation of interaction between Cas9 and Cas12a with target sites in a genome. Black text is a hypothetical target site in double stranded DNA. The PAM is boxed. Red text is the protospacer which is fused to the tracr RNA for Cas9 and a direct repeat (DR) for Cas12a (blue text) in the gRNA. Base pairing between the protospacer and target genomic strand when a PAM is located as shown allows double strand breaks to be made by the Cas nucleases. Position of DNA strand breaks indicated with black triangles