Abstract：
The determination of the atomic resolution structure of biomacromolecules is essential for understanding details of their function. Traditionally, such a structure determination has been performed with crystallographic or nuclear resonance methods, but during the last decade, cryogenic transmission electron microscopy (cryo-TEM) has become an equally important tool. As the blotting and flash-freezing of the samples can induce conformational changes, external validation tools are required to ensure that the vitrified samples are representative of the solution. Although many validation tools have already been developed, most of them rely on fully resolved atomic models, which prevents early screening of the cryo-TEM maps. Here, a novel and automated method for performing such a validation utilizing small-angle X-ray scattering measurements, publicly available through the new software package AUSAXS, is introduced and implemented. The method has been tested on both simulated and experimental data, where it was shown to work remarkably well as a validation tool. The method provides a dummy atomic model derived from the EM map which best represents the solution structure.
摘要：
确定生物大分子的原子分辨率结构对于了解其功能的细节至关重要。传统上,这样的结构确定已经用晶体学或核磁共振方法进行，但是在过去的十年里，低温透射电子显微镜（cryo-TEM）已经成为一个同样重要的工具。由于样品的印迹和快速冷冻可以引起构象变化，需要使用外部验证工具来确保玻璃化样品代表溶液。尽管已经开发了许多验证工具，它们中的大多数依赖于完全解析的原子模型，这阻止了低温TEM图的早期筛查。这里,一种利用小角度X射线散射测量来执行这种验证的新颖且自动化的方法，通过新的AUSAXS软件包公开可用，介绍并实施。该方法已经在模拟和实验数据上进行了测试，在那里，它被证明作为一个验证工具非常好地工作。该方法提供了从EM图导出的虚拟原子模型，该模型最好地表示了解决方案结构。
