8I3Q

Cryo-EM structure of Cas12g-sgRNA binary complex

Summary for 8I3Q

• Entry DOI: 10.2210/pdb8i3q/pdb
• EMDB information: 35154
• Descriptor: RNA (139-MER), Cas12g, ZINC ION (3 entities in total)
• Functional Keywords: crispr-cas, rna binding protein
• Biological source: Escherichia coli; More
• Total number of polymer chains: 2
• Total formula weight: 134684.78

Authors

Ouyang, S.Y.,Liu, M.X.,Li, Z.K. (deposition date: 2023-01-17, release date: 2023-09-06, Last modification date: 2023-10-04)

Primary citation

Liu, M.,Li, Z.,Chen, J.,Lin, J.,Lu, Q.,Ye, Y.,Zhang, H.,Zhang, B.,Ouyang, S.
Structural transitions upon guide RNA binding and their importance in Cas12g-mediated RNA cleavage.
Plos Genet., 19:e1010930-e1010930, 2023

PubMed Abstract: Cas12g is an endonuclease belonging to the type V RNA-guided CRISPR-Cas family. It is known for its ability to cleave RNA substrates using a conserved endonuclease active site located in the RuvC domain. In this study, we determined the crystal structure of apo-Cas12g, the cryo-EM structure of the Cas12g-sgRNA binary complex and investigated conformational changes that occur during the transition from the apo state to the Cas12g-sgRNA binary complex. The conserved zinc finger motifs in Cas12g undergo an ordered-to-disordered transition from the apo to the sgRNA-bound state and their mutations negatively impact on target RNA cleavage. Moreover, we identified a lid motif in the RuvC domain that undergoes transformation from a helix to loop to regulate the access to the RuvC active site and subsequent cleavage of the RNA substrate. Overall, our study provides valuable insights into the mechanisms by which Cas12g recognizes sgRNA and the conformational changes it undergoes from sgRNA binding to the activation of the RNase active site, thereby laying a foundation for the potential repurposing of Cas12g as a tool for RNA-editing.

PubMed: 37729124
DOI: 10.1371/journal.pgen.1010930

Experimental method

ELECTRON MICROSCOPY (3.1 Å)