Engineered hyperactive Cas9 enzymes

Here we used computational design to engineer Cas9 enzymes with substantially higher editing activities. We used genetic circuits linked to cell survival in yeast to enable quantitative assessment of Cas9 activity and discovered epistasis between mutated regions. These hyperactive mutants function efficiently in mammalian cells and introduce larger and more extensive mutations into targeted genomic regions, providing new tools to enhance and expand the possible applications of CRISPR-based gene editing.