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bioRxiv · 10.1101/2022.12.16.519550

The compact CasPi (Cas12l) bracelet "provides" a unique structural platform for DNA manipulation

Sun, A.·Li, C.·Chen, Z.·Zhang, S.·Li, D.·Yang, Y.·Li, L.-Q.·Zhao, Y.·Wang, K.·Li, Z.·Liu, J.·Liu, S.·Wang, J.·Liu, J.-J. G.
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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-Cas{pi} (Cas12l) ([~]860 aa), from the environmental metagenome. Complexed with a large guide-RNA ([~]170 nt) comprising the tracrRNA and crRNA, Cas{pi} (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 Cas{pi} effector encircling the DNA target at 3.4-[A] resolution, substantially different from the canonical two-lobe architectures of Cas12 and Cas9 nucleases. And 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 manipulations.

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Sun, A., Li, C., Chen, Z., Zhang, S., Li, D., Yang, Y., Li, L.-Q., Zhao, Y., Wang, K., Li, Z., Liu, J., Liu, S., Wang, J., Liu, J.-J. G.. 2022-12-16. The compact CasPi (Cas12l) bracelet "provides" a unique structural platform for DNA manipulation. https://doi.org/10.1101/2022.12.16.519550

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