Burke Jordan E, Butcher Samuel E
Department of Biochemistry, University of Wisconsin, Madison, Wisconsin, USA.
Curr Protoc Nucleic Acid Chem. 2012 Dec;Chapter 7:Unit7.18. doi: 10.1002/0471142700.nc0718s51.
Small angle X-ray scattering (SAXS) is a powerful method for investigating macromolecular structure in solution. SAXS data provide information about the size and shape of a molecule with a resolution of ∼2 to 3 nm. SAXS is particularly useful for the investigation of nucleic acids, which scatter X-rays strongly due to the electron-rich phosphate backbone. Therefore, SAXS has become an increasingly popular method for modeling nucleic acid structures, an endeavor made tractable by the highly regular helical nature of nucleic acid secondary structures. Recently, SAXS was used in combination with NMR to filter and refine all-atom models of a U2/U6 small nuclear RNA complex. In this unit, general protocols for sample preparation, data acquisition, and data analysis and processing are given. Additionally, examples of correctly and incorrectly processed SAXS data and expected results are provided.
小角X射线散射（SAXS）是研究溶液中大分子结构的一种强大方法。SAXS数据提供了有关分子大小和形状的信息，分辨率约为2至3纳米。SAXS对于研究核酸特别有用，由于富含电子的磷酸骨架，核酸能强烈散射X射线。因此，SAXS已成为构建核酸结构模型越来越常用的方法，核酸二级结构高度规则的螺旋性质使得这项工作变得可行。最近，SAXS与核磁共振（NMR）结合使用，对U2/U6小核RNA复合体的全原子模型进行筛选和优化。本单元给出了样品制备、数据采集以及数据分析和处理的一般方案。此外，还提供了正确和错误处理的SAXS数据示例以及预期结果。
