Modes of inhibition used by phage anti-CRISPRs to evade type I-C Cascade
O’Brien RE, Bravo JPK, Ramos D, Hibshman GN, Wright JT, Taylor DW. 2022. Modes of inhibition used by phage anti-CRISPRs to evade type I-C Cascade. bioRxiv, 10.1101/2022.06.15.496202.
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https://doi.org/10.1101/2022.06.15.496202
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Author
O’Brien, Roisin E.;
Bravo, JackISTA ;
Ramos, Delisa;
Hibshman, Grace N.;
Wright, Jacquelyn T.;
Taylor, David W.
Abstract
Cascades are RNA-guided multi-subunit CRISPR-Cas surveillances complexes that target foreign nucleic acids for destruction. Here, we present a 2.9-Å resolution cryo-electron (cryo-EM) structure of the <jats:italic>D. vulgaris</jats:italic> type I-C Cascade bound to a double-stranded (ds)DNA target. Our data shows how the 5’-TTC-3’ protospacer adjacent motif (PAM) sequence is recognized, and provides a unique mechanism through which the displaced, single-stranded non-target strand (NTS) is stabilized via stacking interactions with protein subunits in order to favor R-loop formation and prevent dsDNA re-annealing. Additionally, we provide structural insights into how diverse anti-CRISPR (Acr) proteins utilize distinct strategies to achieve a shared mechanism of type I-C Cascade inhibition by blocking initial DNA binding. These observations provide a structural basis for directional R-loop formation and reveal how divergent Acr proteins have converged upon common molecular mechanisms to efficiently shut down CRISPR immunity.
Publishing Year
Date Published
2022-06-15
Journal Title
bioRxiv
Publisher
Cold Spring Harbor Laboratory
IST-REx-ID
Cite this
O’Brien RE, Bravo JPK, Ramos D, Hibshman GN, Wright JT, Taylor DW. Modes of inhibition used by phage anti-CRISPRs to evade type I-C Cascade. bioRxiv. 2022. doi:10.1101/2022.06.15.496202
O’Brien, R. E., Bravo, J. P. K., Ramos, D., Hibshman, G. N., Wright, J. T., & Taylor, D. W. (2022). Modes of inhibition used by phage anti-CRISPRs to evade type I-C Cascade. bioRxiv. Cold Spring Harbor Laboratory. https://doi.org/10.1101/2022.06.15.496202
O’Brien, Roisin E., Jack Peter Kelly Bravo, Delisa Ramos, Grace N. Hibshman, Jacquelyn T. Wright, and David W. Taylor. “Modes of Inhibition Used by Phage Anti-CRISPRs to Evade Type I-C Cascade.” BioRxiv. Cold Spring Harbor Laboratory, 2022. https://doi.org/10.1101/2022.06.15.496202.
R. E. O’Brien, J. P. K. Bravo, D. Ramos, G. N. Hibshman, J. T. Wright, and D. W. Taylor, “Modes of inhibition used by phage anti-CRISPRs to evade type I-C Cascade,” bioRxiv. Cold Spring Harbor Laboratory, 2022.
O’Brien RE, Bravo JPK, Ramos D, Hibshman GN, Wright JT, Taylor DW. 2022. Modes of inhibition used by phage anti-CRISPRs to evade type I-C Cascade. bioRxiv, 10.1101/2022.06.15.496202.
O’Brien, Roisin E., et al. “Modes of Inhibition Used by Phage Anti-CRISPRs to Evade Type I-C Cascade.” BioRxiv, Cold Spring Harbor Laboratory, 2022, doi:10.1101/2022.06.15.496202.
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