Download MendeleyScaffold-enabled high-resolution cryo-EM structure determination of RNA.
Haack, D.B., Rudolfs, B., Jin, S., Weeks, K.M., Toor, N.(2024) bioRxiv
- PubMed: 38915706
- DOI: https://doi.org/10.1101/2024.06.10.598011
- Primary Citation of Related Structures:
9C6I, 9C6J, 9C6K - PubMed Abstract:
Cryo-EM structure determination of protein-free RNAs has remained difficult with most attempts yielding low to moderate resolution and lacking nucleotide-level detail. These difficulties are compounded for small RNAs as cryo-EM is inherently more difficult for lower molecular weight macromolecules. Here we present a strategy for fusing small RNAs to a group II intron that yields high resolution structures of the appended RNA, which we demonstrate with the 86-nucleotide thiamine pyrophosphate (TPP) riboswitch, and visualizing the riboswitch ligand binding pocket at 2.5 Å resolution. We also determined the structure of the ligand-free apo state and observe that the aptamer domain of the riboswitch undergoes a large-scale conformational change upon ligand binding, illustrating how small molecule binding to an RNA can induce large effects on gene expression. This study both sets a new standard for cryo-EM riboswitch visualization and offers a versatile strategy applicable to a broad range of small to moderate-sized RNAs, which were previously intractable for high-resolution cryo-EM studies.
Organizational Affiliation:
Department of Chemistry and Biochemistry, University of California, San Diego, La Jolla, CA.
