CRISPR-Cas9: Activity System of Streptococcus pyogenes Cas9.
Streptococcus pyogenes Cas9, a multitude of CRISPR-Cas9 variants have been engineered and employed for experiments worldwide. Although all these systems are targeting and leaving a specific DNA sequence, they also exhibit relatively high off-target activities with potentially harmful effects.
Led by Professor Hyongbum Henry Kim, the research team of the Center for Nanomedicine, within the institute for basic science, has achieved the most extensive high-throughput analysis of CRISPR-Cas activities.
The team developed deep-learning-based computational models that predict the activities of SpCas-9 variants fo different DNA sequences.
This surpassed all previous reports, which had evaluated only up to three Cas9 systems. IBS researchers compared 13 SpCas9 variants and defined which four-nucleotide sequences can be used as a protospacer adjacent motif- a short DNA sequence that is required for Cas-9 to cut.
Additionally, they Evaluated the specially of six different high-fidelity SpCas9 variants and found that evoCas9 has the highest specificity, while the original wild-type SpCas9 has the lowest. Although evoCas9 is very specific, it also shows activity at many targets sequence, other high-fidelity Cas9 variants could be preferred.