Crystallization of RNA

Even as the number of RNA structures determined and under study multiplies, the critical step in X-ray diffraction analysis, growth of single well-ord ered crystals, remains at the boundary between art and science. Recent adva nces in methods of RNA synthesis, purification, and characterization, as we ll as empirical and technical improvements in crystallization techniques, t he development of cryo-crystallography, and the wider availability of brigh t, tunable, X-rays from synchrotron sources are improving the chances of ob taining RNA crystals suitable for X-ray structural analysis. In this review , we summarize the current status of the design, preparation, purification, and analysis of RNA for crystallization and describe the latest approaches to obtaining diffraction-quality crystals.