Summary information and primary citation
- PDB-id
- 7yoj; SNAP-derived features in text and JSON formats;
DNAproDB
- Class
- RNA binding protein-DNA-RNA
- Method
- cryo-EM (3.36 Å)
- Summary
- Structure of caspi with guide RNA and target DNA
- Reference
- Sun A, Li CP, Chen Z, Zhang S, Li DY, Yang Y, Li LQ, Zhao Y, Wang K, Li Z, Liu J, Liu S, Wang J, Liu JG (2023): "The compact Cas pi (Cas12l) 'bracelet' provides a unique structural platform for DNA manipulation." Cell Res., 33, 229-244. doi: 10.1038/s41422-022-00771-2.
- Abstract
- CRISPR-Cas modules serve as the adaptive nucleic acid immune systems for prokaryotes, and provide versatile tools for nucleic acid manipulation in various organisms. Here, we discovered a new miniature type V system, CRISPR-Casπ (Cas12l) (~860 aa), from the environmental metagenome. Complexed with a large guide RNA (~170 nt) comprising the tracrRNA and crRNA, Casπ (Cas12l) recognizes a unique 5' C-rich PAM for DNA cleavage under a broad range of biochemical conditions, and generates gene editing in mammalian cells. Cryo-EM study reveals a 'bracelet' architecture of Casπ effector encircling the DNA target at 3.4 Å resolution, substantially different from the canonical 'two-lobe' architectures of Cas12 and Cas9 nucleases. The large guide RNA serves as a 'two-arm' scaffold for effector assembly. Our study expands the knowledge of DNA targeting mechanisms by CRISPR effectors, and offers an efficient but compact platform for DNA manipulation.
