RNA structures and dynamics with Å resolution revealed by x-ray free-electron lasers

Area of Science:

• Biochemistry and Molecular Biology
• Structural Biology
• Biophysics

Background:

• RNA molecules fold into complex structures crucial for their biological functions.
• Determining RNA structures is challenging due to their high charge and dynamic nature.

Purpose of the Study:

• To introduce a novel approach for revealing angstrom-scale features in RNA structures.
• To observe the dynamic process of RNA folding with millisecond time resolution.

Main Methods:

• Utilizing the high brilliance of X-ray free-electron laser (XFEL) sources.
• Employing wide-angle solution scattering experiments.
• Time-resolved structural analysis.

Main Results:

• Identified previously unrecognized structural signatures in RNA secondary and tertiary structures.
• Observed RNA folding from a single strand through a base-paired intermediate to a triple-helix conformation.
• Demonstrated that the RNA backbone orchestrates folding, while base stacking locks the final structure.

Conclusions:

• The developed method enables rapid characterization and identification of structural elements in both structured and unstructured RNAs.
• This approach is applicable to both equilibrium and time-resolved experiments.
• The findings advance our understanding of RNA folding dynamics and structural determination.