AcrIF9 tethers non-sequence specific dsDNA to the CRISPR RNA-guided surveillance complex

Nature Communications - Tập 11 Số 1
Marscha Hirschi1, Wangting Lu2, Andrew Santiago‐Frangos3, Royce A. Wilkinson3, Sarah Golden3, Alan R. Davidson2, Gabriel C. Lander1, Blake Wiedenheft3
1Department of Integrative Structural and Computational Biology, The Scripps Research Institute, 10550 North Torrey Pines Road, La Jolla, CA, 92121, USA
2Department of Molecular Genetics, and Department of Biochemistry, University of Toronto, 661 University Avenue, Room 1634, Toronto, ON, M5G 1M1, Canada
3Department of Microbiology and Immunology, Montana State University, 1156 South 11th Avenue, Bozeman, MT, 59717, USA

Tóm tắt

AbstractBacteria 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.

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Nature Communications

Tập 11 Số 1

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