Application of Synchrotron Radiation Circular Dichroism for Structural Analysis of RNAs.

Circular dichroism (CD) spectroscopy is a rapid and straightforward technique that provides valuable insights into the conformation of nucleic acids and proteins. As a highly sensitive electronic absorption method, CD can detect even subtle structural changes in asymmetric chiral-molecules. While numerous reviews focus on analyzing the structure of deoxyribonucleic acid (DNA) using CD, studies on ribonucleic acid (RNA) remain relatively limited, despite RNA's critical roles in various cellular processes. This chapter highlights the application of Synchrotron Radiation Circular Dichroism (SRCD) in RNA analysis. Compared to conventional CD, SRCD extends the spectral range down to 170 nm, significantly enhancing the ability to study RNA structure. SRCD thus enables the precise examination of helical parameters, base pairing and stacking, alternative RNA structures, temperature-induced changes, thermodynamic parameters, and ribonucleoprotein complexes. Furthermore, we discuss how SRCD can be employed to investigate protein-induced structural changes in RNA, such as stabilization or alterations in structural parameters.