Details

Autor(en) / Beteiligte

• Zhang, Xiaojing
• Li, Shanshan
• Pintilie, Grigore
• Palo, Michael Z
• Zhang, Kaiming

Titel

Snapshots of the first-step self-splicing of Tetrahymena ribozyme revealed by cryo-EM

Ist Teil von

• Nucleic acids research, 2023-02, Vol.51 (3), p.1317-1325

Ort / Verlag

England

Erscheinungsjahr

2023

Quelle

MEDLINE

Beschreibungen/Notizen

• Tetrahymena ribozyme is a group I intron, whose self-splicing is the result of two sequential ester-transfer reactions. To understand how it facilitates catalysis in the first self-splicing reaction, we used cryogenic electron microscopy (cryo-EM) to resolve the structures of L-16 Tetrahymena ribozyme complexed with a 11-nucleotide 5'-splice site analog substrate. Four conformations were achieved to 4.14, 3.18, 3.09 and 2.98 Å resolutions, respectively, corresponding to different splicing intermediates during the first enzymatic reaction. Comparison of these structures reveals structural alterations, including large conformational changes in IGS/IGSext (P1-P1ext duplex) and J5/4, as well as subtle local rearrangements in the G-binding site. These structural changes are required for the enzymatic activity of the Tetrahymena ribozyme. Our study demonstrates the ability of cryo-EM to capture dynamic RNA structural changes, ushering in a new era in the analysis of RNA structure-function by cryo-EM.