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Title | Cryo-EM structures of full-length Tetrahymena ribozyme at 3.1 Å resolution. |
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Journal, issue, pages | Nature, Vol. 596, Issue 7873, Page 603-607, Year 2021 |
Publish date | Aug 11, 2021 |
Authors | Zhaoming Su / Kaiming Zhang / Kalli Kappel / Shanshan Li / Michael Z Palo / Grigore D Pintilie / Ramya Rangan / Bingnan Luo / Yuquan Wei / Rhiju Das / Wah Chiu / |
PubMed Abstract | Single-particle cryogenic electron microscopy (cryo-EM) has become a standard technique for determining protein structures at atomic resolution. However, cryo-EM studies of protein-free RNA are in ...Single-particle cryogenic electron microscopy (cryo-EM) has become a standard technique for determining protein structures at atomic resolution. However, cryo-EM studies of protein-free RNA are in their early days. The Tetrahymena thermophila group I self-splicing intron was the first ribozyme to be discovered and has been a prominent model system for the study of RNA catalysis and structure-function relationships, but its full structure remains unknown. Here we report cryo-EM structures of the full-length Tetrahymena ribozyme in substrate-free and bound states at a resolution of 3.1 Å. Newly resolved peripheral regions form two coaxially stacked helices; these are interconnected by two kissing loop pseudoknots that wrap around the catalytic core and include two previously unforeseen (to our knowledge) tertiary interactions. The global architecture is nearly identical in both states; only the internal guide sequence and guanosine binding site undergo a large conformational change and a localized shift, respectively, upon binding of RNA substrates. These results provide a long-sought structural view of a paradigmatic RNA enzyme and signal a new era for the cryo-EM-based study of structure-function relationships in ribozymes. |
External links | Nature / PubMed:34381213 / PubMed Central |
Methods | EM (single particle) |
Resolution | 3.05 - 3.14 Å |
Structure data | EMDB-31385, PDB-7ez0: EMDB-31386, PDB-7ez2: |
Chemicals | ChemComp-MG: |
Source |
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Keywords | RNA / RNA structure / Tetrahymena ribozyme |