A guide RNA sequence controls CRISPR-Cas9 cutting activity

A guide RNA repeat checkpoint (GRC) was discovered that senses the structure and dynamics of the guide repeat region.

• The GRC coordinates with other checkpoint mechanisms that recognize spacer-target R-loop fidelity.
• This coordination is involved in licensing target cleavage during the gene editing process.
• Properties of dual guide RNA (dgRNA) and single guide RNA (sgRNA) could be combined into guide repeat-truncated sgRNAs (grtRNAs).
• Using grtRNAs with high-fidelity Cas9 variants may help to reduce off-target editing.
• The findings provide insights into how Cas9 catalysis is governed by guide RNA structure sensing.

Simplified