Download MendeleyStructural basis for broad anti-phage immunity by DISARM.
Bravo, J.P.K., Aparicio-Maldonado, C., Nobrega, F.L., Brouns, S.J.J., Taylor, D.W.(2022) Nat Commun 13: 2987-2987
- PubMed: 35624106
- DOI: https://doi.org/10.1038/s41467-022-30673-1
- Primary Citation of Related Structures:
7S9V, 7S9W - PubMed Abstract:
In the evolutionary arms race against phage, bacteria have assembled a diverse arsenal of antiviral immune strategies. While the recently discovered DISARM (Defense Island System Associated with Restriction-Modification) systems can provide protection against a wide range of phage, the molecular mechanisms that underpin broad antiviral targeting but avoiding autoimmunity remain enigmatic. Here, we report cryo-EM structures of the core DISARM complex, DrmAB, both alone and in complex with an unmethylated phage DNA mimetic. These structures reveal that DrmAB core complex is autoinhibited by a trigger loop (TL) within DrmA and binding to DNA substrates containing a 5' overhang dislodges the TL, initiating a long-range structural rearrangement for DrmAB activation. Together with structure-guided in vivo studies, our work provides insights into the mechanism of phage DNA recognition and specific activation of this widespread antiviral defense system.
Organizational Affiliation:
Department of Molecular Biosciences, University of Texas at Austin, Austin, TX, 78712, USA.
