7JHY

Type IV-B CRISPR Complex

Summary for 7JHY

• Entry DOI: 10.2210/pdb7jhy/pdb
• EMDB information: 22340
• Descriptor: Csf2 (Cas7), RNA (31-MER), Csf4 (Cas11) (3 entities in total)
• Functional Keywords: crispr complex, immune system-rna complex, immune system/rna
• Biological source: Mycobacterium sp. JS623; More
• Total number of polymer chains: 12
• Total formula weight: 291768.70

Authors

Bravo, J.P.K.,Taylor, D.W. (deposition date: 2020-07-21, release date: 2021-03-31, Last modification date: 2025-05-28)

Primary citation

Zhou, Y.,Bravo, J.P.K.,Taylor, H.N.,Steens, J.A.,Jackson, R.N.,Staals, R.H.J.,Taylor, D.W.
Structure of a type IV CRISPR-Cas ribonucleoprotein complex.
Iscience, 24:102201-102201, 2021

PubMed Abstract: We reveal the cryo-electron microscopy structure of a type IV-B CRISPR ribonucleoprotein (RNP) complex (Csf) at 3.9-Å resolution. The complex best resembles the type III-A CRISPR Csm effector complex, consisting of a Cas7-like (Csf2) filament intertwined with a small subunit (Cas11) filament, but the complex lacks subunits for RNA processing and target DNA cleavage. Surprisingly, instead of assembling around a CRISPR-derived RNA (crRNA), the complex assembles upon heterogeneous RNA of a regular length arranged in a pseudo-A-form configuration. These findings provide a high-resolution glimpse into the assembly and function of enigmatic type IV CRISPR systems, expanding our understanding of class I CRISPR-Cas system architecture, and suggesting a function for type IV-B RNPs that may be distinct from other class 1 CRISPR-associated systems.

PubMed: 33733066
DOI: 10.1016/j.isci.2021.102201

Experimental method

ELECTRON MICROSCOPY (3.9 Å)