Improving AtCas9 for more effective and wider genome editing

The engineered AtCas9-Z7 variant achieved a 5.76-fold increase in base editing efficiency compared to wild-type AtCas9.

• Loop engineering enhances the performance of Cas9, a key enzyme in genome editing.
• Substituting specific loops from different Cas9 variants can improve nuclease and base editing efficiency.
• The Z7 variant maintains high binding affinity even under magnesium-limiting conditions, which are often encountered in mammalian cells.
• Molecular dynamics simulations indicate that Z7 adopts a stable, compact conformation.
• Combining loop engineering with structure-guided point mutations further enhances Cas9 activity.
• This approach also increased editing efficiency in other Cas9 variants at non-canonical PAMs.

Simplified