6W64

Cryo-EM structure of Cas12i-crRNA-dsDNA complex in I1 state

Summary for 6W64

• Entry DOI: 10.2210/pdb6w64/pdb
• EMDB information: 21541 21551 21552
• Descriptor: Cas12i, crRNA, DNA (25-MER) (3 entities in total)
• Functional Keywords: crispr, hydrolase-dna-rna complex, hydrolase/dna/rna
• Biological source: Lachnospiraceae bacterium ND2006; More
• Total number of polymer chains: 3
• Total formula weight: 145580.19

Authors

Chang, L.,Li, Z.,Zhang, H. (deposition date: 2020-03-16, release date: 2020-09-16, Last modification date: 2024-03-06)

Primary citation

Zhang, H.,Li, Z.,Xiao, R.,Chang, L.
Mechanisms for target recognition and cleavage by the Cas12i RNA-guided endonuclease.
Nat.Struct.Mol.Biol., 27:1069-1076, 2020

PubMed 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.

PubMed: 32895556
DOI: 10.1038/s41594-020-0499-0

Experimental method

ELECTRON MICROSCOPY (3.9 Å)