Imaging Technique Reveals RNA's Dynamic Folding Process

A new study led by researchers from Lawrence Berkeley National Laboratory and Aarhus University has shed light on the intricate folding process of RNA molecules, overcoming long-standing challenges in capturing their dynamic structures. The team employed Individual-Particle cryo-Electron Tomography (IPET) to observe the 3D shapes of single RNA origami molecules without averaging.

Traditional methods like cryo-electron microscopy (cryo-EM) single-particle averaging (SPA) analysis have limitations in studying flexible RNA structures due to their reliance on averaging thousands of molecules. IPET, however, allows for the visualization of individual molecules in various folding stages, providing a more comprehensive view of RNA's structural landscape.

The study, published in Nature Communications, focused on RNA origami—artificially engineered RNA molecules designed to fold into specific nanoscale shapes. By capturing snapshots of these molecules at different folding stages, researchers were able to observe a folding trap and the transition to a more compact form.

"The IPET technique provides us with a more dynamic view of the molecular world," explains Ebbe Andersen, co-lead researcher. "It is our hope that this insight will enable us to engineer the folding of more effective RNA vaccines and dynamic sensors for molecular medicine." 

The researchers created a video demonstrating the IPET process, showcasing the analysis of 120 particles and illustrating the dynamic folding of RNA origami. This new approach offers a promising avenue for understanding and potentially manipulating RNA structures, with implications for vaccine development and molecular medicine.