title: Small-angle X-ray scattering: a bridge between RNA secondary structures and three-dimensional topological structures.
abstract: Whereas the structures of small to medium-sized well folded RNA molecules often can be determined by either X-ray crystallography or NMR spectroscopy, obtaining structural information for large RNAs using experimental, computational, or combined approaches remains a major interest and challenge. RNA is very sensitive to small-angle X-ray scattering (SAXS) due to high electron density along phosphate-sugar backbones, whose scattering contribution dominates SAXS intensity. For this reason, SAXS is particularly useful in obtaining global RNA structural information that outlines backbone topologies and, therefore, molecular envelopes. Such information is extremely valuable in bridging the gap between the secondary structures and three-dimensional topological structures of RNA molecules, particularly those that have proven difficult to study using other structure-determination methods. Here we review published results of RNA topological structures derived from SAXS data or in combination with other experimental data, as well as details on RNA sample preparation for SAXS experiments.
authors.affiliation: NCI Small Angle X-ray Scattering Core Facility, Structural Biophysics Laboratory, National Cancer Institute, National Institutes of Health, United States.
authors.forename: Xianyang
authors.initials: X
authors.lastname: Fang
authors.affiliation: Protein-Nucleic Acid Interaction Section, Structural Biophysics Laboratory, National Cancer Institute, National Institutes of Health, United States.
authors.forename: Jason R
authors.initials: JR
authors.lastname: Stagno
authors.affiliation: Protein-Nucleic Acid Interaction Section, Structural Biophysics Laboratory, National Cancer Institute, National Institutes of Health, United States.
authors.forename: Yuba R
authors.initials: YR
authors.lastname: Bhandari
authors.affiliation: Advanced Photon Source, Argonne National Laboratory, Argonne, IL 60439, United States.
authors.forename: Xiaobing
authors.initials: X
authors.lastname: Zuo
authors.affiliation: NCI Small Angle X-ray Scattering Core Facility, Structural Biophysics Laboratory, National Cancer Institute, National Institutes of Health, United States; Protein-Nucleic Acid Interaction Section, Structural Biophysics Laboratory, National Cancer Institute, National Institutes of Health, United States. Electronic address: wangyunx@mail.nih.gov.
authors.forename: Yun-Xing
authors.initials: YX
authors.lastname: Wang
mesh_terms: D020029:Base Pairing; D019295:Computational Biology / Q000379:methods*; D008958:Models, Molecular; D009690:Nucleic Acid Conformation; D012313:RNA / Q000737:chemistry* / Q000235:genetics; D053838:Scattering, Small Angle; D012984:Software; D013329:Structure-Activity Relationship; D014961:X-Ray Diffraction
chemical_list: D012313:RNA