7EU9

Crystal structure of the selenomethionine(SeMet)-derived Cas12i1 R-loop complex before target DNA cleavage

Summary for 7EU9

• Entry DOI: 10.2210/pdb7eu9/pdb
• Related: 7D2L 7D3J 7D8C
• Descriptor: Cas12i1 D647A mutant, RNA (43-MER), DNA (31-MER), ... (6 entities in total)
• Functional Keywords: cas12i, cas12i1, crispr, rna binding protein
• Biological source: Lachnospiraceae bacterium ND2006; More
• Total number of polymer chains: 4
• Total formula weight: 166714.57

Authors

Zhang, B.,Luo, D.Y.,Li, Y.,OuYang, S.Y. (deposition date: 2021-05-16, release date: 2021-05-26, Last modification date: 2024-11-06)

Primary citation

Zhang, B.,Luo, D.,Li, Y.,Perculija, V.,Chen, J.,Lin, J.,Ye, Y.,Ouyang, S.
Mechanistic insights into the R-loop formation and cleavage in CRISPR-Cas12i1.
Nat Commun, 12:3476-3476, 2021

PubMed Abstract: Cas12i is a newly identified member of the functionally diverse type V CRISPR-Cas effectors. Although Cas12i has the potential to serve as genome-editing tool, its structural and functional characteristics need to be investigated in more detail before effective application. Here we report the crystal structures of the Cas12i1 R-loop complexes before and after target DNA cleavage to elucidate the mechanisms underlying target DNA duplex unwinding, R-loop formation and cis cleavage. The structure of the R-loop complex after target DNA cleavage also provides information regarding trans cleavage. Besides, we report a crystal structure of the Cas12i1 binary complex interacting with a pseudo target oligonucleotide, which mimics target interrogation. Upon target DNA duplex binding, the Cas12i1 PAM-interacting cleft undergoes a remarkable open-to-closed adjustment. Notably, a zipper motif in the Helical-I domain facilitates unzipping of the target DNA duplex. Formation of the 19-bp crRNA-target DNA strand heteroduplex in the R-loop complexes triggers a conformational rearrangement and unleashes the DNase activity. This study provides valuable insights for developing Cas12i1 into a reliable genome-editing tool.

PubMed: 34108490
DOI: 10.1038/s41467-021-23876-5

Experimental method

X-RAY DIFFRACTION (2.35 Å)