6WHI

Cryo-electron microscopy structure of the type I-F CRISPR RNA-guided surveillance complex bound to the anti-CRISPR AcrIF9

Summary for 6WHI

• Entry DOI: 10.2210/pdb6whi/pdb
• EMDB information: 21516 21517
• Descriptor: CRISPR-associated protein Csy1, Type I-F CRISPR-associated protein Csy2, CRISPR-associated protein Csy3, ... (8 entities in total)
• Functional Keywords: type i-f crispr rna-guided surveillance complex, csy complex, immune system-dna-rna complex, immune system/dna/rna
• Biological source: Pseudomonas aeruginosa; More
• Total number of polymer chains: 16
• Total formula weight: 475499.26

Authors

Hirschi, M.,Santiago-Frangos, A.,Wilkinson, R.,Golden, S.M.,Wiedenheft, B.,Lander, G. (deposition date: 2020-04-08, release date: 2020-05-13, Last modification date: 2024-03-06)

Primary citation

Hirschi, M.,Lu, W.T.,Santiago-Frangos, A.,Wilkinson, R.,Golden, S.M.,Davidson, A.R.,Lander, G.C.,Wiedenheft, B.
AcrIF9 tethers non-sequence specific dsDNA to the CRISPR RNA-guided surveillance complex.
Nat Commun, 11:2730-2730, 2020

PubMed Abstract: Bacteria have evolved sophisticated adaptive immune systems, called CRISPR-Cas, that provide sequence-specific protection against phage infection. In turn, phages have evolved a broad spectrum of anti-CRISPRs that suppress these immune systems. Here we report structures of anti-CRISPR protein IF9 (AcrIF9) in complex with the type I-F CRISPR RNA-guided surveillance complex (Csy). In addition to sterically blocking the hybridization of complementary dsDNA to the CRISPR RNA, our results show that AcrIF9 binding also promotes non-sequence-specific engagement with dsDNA, potentially sequestering the complex from target DNA. These findings highlight the versatility of anti-CRISPR mechanisms utilized by phages to suppress CRISPR-mediated immune systems.

PubMed: 32483187
DOI: 10.1038/s41467-020-16512-1

Experimental method

ELECTRON MICROSCOPY (4.2 Å)