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Title | Molecular basis of RADAR anti-phage supramolecular assemblies. |
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Journal, issue, pages | Cell, Vol. 186, Issue 5, Page 999-1012.e20, Year 2023 |
Publish date | Mar 2, 2023 |
Authors | Yina Gao / Xiu Luo / Peipei Li / Zhaolong Li / Feng Ye / Songqing Liu / Pu Gao / |
PubMed Abstract | Adenosine-to-inosine RNA editing has been proposed to be involved in a bacterial anti-phage defense system called RADAR. RADAR contains an adenosine triphosphatase (RdrA) and an adenosine deaminase ...Adenosine-to-inosine RNA editing has been proposed to be involved in a bacterial anti-phage defense system called RADAR. RADAR contains an adenosine triphosphatase (RdrA) and an adenosine deaminase (RdrB). Here, we report cryo-EM structures of RdrA, RdrB, and currently identified RdrA-RdrB complexes in the presence or absence of RNA and ATP. RdrB assembles into a dodecameric cage with catalytic pockets facing outward, while RdrA adopts both autoinhibited tetradecameric and activation-competent heptameric rings. Structural and functional data suggest a model in which RNA is loaded through the bottom section of the RdrA ring and translocated along its inner channel, a process likely coupled with ATP-binding status. Intriguingly, up to twelve RdrA rings can dock one RdrB cage with precise alignments between deaminase catalytic pockets and RNA-translocation channels, indicative of enzymatic coupling of RNA translocation and deamination. Our data uncover an interesting mechanism of enzymatic coupling and anti-phage defense through supramolecular assemblies. |
External links | Cell / PubMed:36764292 |
Methods | EM (single particle) |
Resolution | 2.58 - 7.03 Å |
Structure data | EMDB-34962, PDB-8hr7: EMDB-34963, PDB-8hr8: EMDB-34964, PDB-8hr9: EMDB-34965, PDB-8hra: EMDB-34966, PDB-8hrb: EMDB-34967, PDB-8hrc: EMDB-34969: Cryo-EM map of the RdrA-RdrB complex in 2:1 ratio EMDB-34970: Cryo-EM map of the RdrA-RdrB complex in 3:1 ratio EMDB-34971: Cryo-EM map of the RdrA-RdrB complex in 5:1 ratio |
Chemicals | ChemComp-ATP: |
Source |
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Keywords | IMMUNE SYSTEM / Cryoelectron microscopy / adenosine triphosphatase / adenosine deaminase |