一句话说清两者的区别
Cas9 and Cas12 are cousins. Cas9 needs a G-rich signal next to its target and cuts cleanly across both strands. Cas12 needs a T-rich signal, cuts at an angle leaving ragged ends, can process several guides from one strand of RNA, and, usefully for diagnostics but awkwardly inside cells, keeps chopping up loose DNA once it has found its target.
| 方面 | CRISPR-Cas9 | CRISPR-Cas12a |
|---|---|---|
| Sequence signal required | G-rich PAM (NGG), after the target | T-rich PAM (TTTV), before the target |
| Where it can aim | GC-rich regions favoured | AT-rich regions accessible |
| Cut shape | Blunt | Staggered, with overhangs |
| Multiple guides | Each needs its own transcript | Processes its own guide array |
| Collateral activity | None | Cuts loose single-stranded DNA once activated |
| Diagnostics | Limited use | The basis of DETECTR-class tests |
| Clinical use | Approved medicine | Cell therapy trials |
Sources
- Cell (Zetsche et al.) · 2015
Cpf1 is a single RNA-guided endonuclease of a class 2 CRISPR-Cas system ↗