7R6M

Post-2S intermediate of the Tetrahymena group I intron, symmetry-expanded monomer from a synthetic dimeric construct

Summary for 7R6M

• Entry DOI: 10.2210/pdb7r6m/pdb
• EMDB information: 24282
• Descriptor: Group I intron, Ligated exon mimic of the Group I intron, MAGNESIUM ION (3 entities in total)
• Functional Keywords: ribozyme, group i intron, catalytic rna, rna
• Biological source: Tetrahymena thermophila; More
• Total number of polymer chains: 2
• Total formula weight: 132684.18

Authors

Thelot, F.,Liu, D.,Liao, M.,Yin, P. (deposition date: 2021-06-22, release date: 2022-05-04, Last modification date: 2024-06-05)

Primary citation

Liu, D.,Thelot, F.A.,Piccirilli, J.A.,Liao, M.,Yin, P.
Sub-3- angstrom cryo-EM structure of RNA enabled by engineered homomeric self-assembly.
Nat.Methods, 19:576-585, 2022

PubMed Abstract: High-resolution structural studies are essential for understanding the folding and function of diverse RNAs. Herein, we present a nanoarchitectural engineering strategy for efficient structural determination of RNA-only structures using single-particle cryogenic electron microscopy (cryo-EM). This strategy-ROCK (RNA oligomerization-enabled cryo-EM via installing kissing loops)-involves installing kissing-loop sequences onto the functionally nonessential stems of RNAs for homomeric self-assembly into closed rings with multiplied molecular weights and mitigated structural flexibility. ROCK enables cryo-EM reconstruction of the Tetrahymena group I intron at 2.98-Å resolution overall (2.85 Å for the core), allowing de novo model building of the complete RNA, including the previously unknown peripheral domains. ROCK is further applied to two smaller RNAs-the Azoarcus group I intron and the FMN riboswitch, revealing the conformational change of the former and the bound ligand in the latter. ROCK holds promise to greatly facilitate the use of cryo-EM in RNA structural studies.

PubMed: 35501384
DOI: 10.1038/s41592-022-01455-w

Experimental method

ELECTRON MICROSCOPY (3.68 Å)