7XG4

CryoEM structure of type IV-A CasDinG bound NTS-nicked Csf-crRNA-dsDNA quaternary complex in a second state

Summary for 7XG4

• Entry DOI: 10.2210/pdb7xg4/pdb
• EMDB information: 33185
• Descriptor: Csf1, Csf3, Csf2, ... (9 entities in total)
• Functional Keywords: nuclease, structural protein-rna-dna complex, structural protein/rna/dna
• Biological source: Pseudomonas aeruginosa; More
• Total number of polymer chains: 12
• Total formula weight: 384834.43

Authors

Zhang, J.T.,Cui, N.,Huang, H.D.,Jia, N. (deposition date: 2022-04-02, release date: 2023-08-09, Last modification date: 2024-07-03)

Primary citation

Cui, N.,Zhang, J.T.,Liu, Y.,Liu, Y.,Liu, X.Y.,Wang, C.,Huang, H.,Jia, N.
Type IV-A CRISPR-Csf complex: Assembly, dsDNA targeting, and CasDinG recruitment.
Mol.Cell, 83:2493-2508.e5, 2023

PubMed Abstract: Type IV CRISPR-Cas systems, which are primarily found on plasmids and exhibit a strong plasmid-targeting preference, are the only one of the six known CRISPR-Cas types for which the mechanistic details of their function remain unknown. Here, we provide high-resolution functional snapshots of type IV-A Csf complexes before and after target dsDNA binding, either in the absence or presence of CasDinG, revealing the mechanisms underlying Csf complex assembly, "DWN" PAM-dependent dsDNA targeting, R-loop formation, and CasDinG recruitment. Furthermore, we establish that CasDinG, a signature DinG family helicase, harbors ssDNA-stimulated ATPase activity and ATP-dependent 5'-3' DNA helicase activity. In addition, we show that CasDinG unwinds the non-target strand (NTS) and target strand (TS) of target dsDNA from the Csf complex. These molecular details advance our mechanistic understanding of type IV-A CRISPR-Csf function and should enable Csf complexes to be harnessed as genome-engineering tools for biotechnological applications.

PubMed: 37343553
DOI: 10.1016/j.molcel.2023.05.036

Experimental method

ELECTRON MICROSCOPY (3.7 Å)