Molecular basis of target RNA cleavage by Cas13 III

However, to this date, the in vivo RNA cleavage mechanisms remain poorly understood. Here, we combine in vitro and in vivo methods to elucidate the exact cleavage sites of Cas13.

We reveal that some subtypes of Cas13, including Cas13b and Cas13bt, cleave the target RNA in predominant positions, and rational engineering of Cas13 further improves the precision. Building on this fact, we developed RNA segment editing (RSE), a targeted RNA cleavage and repair method, to restore dysfunctional RNA in cells. We anticipate that RSE will enable precision RNA engineering for therapeutics and basic research.