8). The tracrRNA hybridizes to the “repeat” portion of each crRNA within the transcribed array. Host-derived RNase III then cleaves the formed RNA stem to generate a processed crRNA:tracrRNA duplex utilized by Cas9 (
6). What remains unclear is whether crRNAs are confined to CRISPR-Cas loci or can be derived from elsewhere in the genome. Here, we show that crRNAs can be derived from host RNAs outside the CRISPR-Cas locus, inspiring a novel Cas9-based diagnostic platform that allows scalable detection of multiple biomarkers in a single test.
Cellular RNAs bound to Cas9 from
C. jejuni resemble crRNAs
C. jejuni NCTC11168 (CjeCas9) revealed crRNA-guided RNA targeting by CjeCas9 (