Advances in methods for native expression and purification of RNA for structural studies.

Many RNAs present unique challenges in obtaining material suitable for structural or biophysical characterization. These issues include synthesis of chemically and conformationally homogeneous RNAs, refolding RNA purified using denaturing preparation techniques, and avoiding chemical damage. To address these challenges, new methodologies in RNA expression and purification have been developed seeking to emulate those commonly used for proteins. In this review, recent developments in the preparation of high-quality RNA for structural biology and biophysical applications are discussed, with an emphasis on native methods.