 Likewise, biochemical and structural analysis of AcrIF3 showed its capacity of binding to Cas3 as a dimer so as to prevent the recruitment of Cas3 to the Cascade complex.Finally, thanks to biochemical and structural AcrIIC1 studies, it was found that it binds to the active site of the HNH endonuclease domain in Cas9, which prevents DNA from cleaving.Thus, it turns Cas9 into an inactive but DNA bound state.