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-Structure paper
Title | Structure of a type IV CRISPR-Cas ribonucleoprotein complex. |
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Journal, issue, pages | iScience, Vol. 24, Issue 3, Page 102201, Year 2021 |
Publish date | Mar 19, 2021 |
Authors | Yi Zhou / Jack P K Bravo / Hannah N Taylor / Jurre A Steens / Ryan N Jackson / Raymond H J Staals / David W Taylor / |
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 ...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. |
External links | iScience / PubMed:33733066 / PubMed Central |
Methods | EM (single particle) |
Resolution | 3.9 Å |
Structure data | EMDB-22340, PDB-7jhy: |
Source |
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Keywords | IMMUNE SYSTEM/RNA / CRISPR Complex / IMMUNE SYSTEM-RNA complex |