Summary information and primary citation
- PDB-id
- 6w5c; DSSR-derived features in text and JSON formats
- Class
- hydrolase-DNA-RNA
- Method
- cryo-EM (2.9 Å)
- Summary
- cryo-EM structure of cas12i(e894a)-crrna-dsDNA complex
- Reference
- Zhang H, Li Z, Xiao R, Chang L (2020): "Mechanisms for target recognition and cleavage by the Cas12i RNA-guided endonuclease." Nat.Struct.Mol.Biol., 27, 1069-1076. doi: 10.1038/s41594-020-0499-0.
- Abstract
- Cas12i is a recently identified type V CRISPR-Cas endonuclease that predominantly cleaves the non-target strand of a double-stranded DNA substrate. This nicking activity of Cas12i could potentially be used for genome editing with high specificity. To elucidate its mechanisms for target recognition and cleavage, we determined cryo-EM structures of Cas12i in multiple functional states. Cas12i pre-orders a seven-nucleotide seed sequence of the crRNA for target recognition and undergoes a two-step activation through crRNA-DNA hybridization. Formation of 14 base pairs activates the nickase activity, and 28-bp hybridization promotes cleavage of the target strand. The atomic structures and mechanistic insights gained should facilitate the manipulation of Cas12i for genome editing applications.
