Department of Molecular Structural Biology, Institute of Microbiology & Genetics, GZMB, Georg-August-University Göttingen, Justus-von-Liebig-Weg 11, 37077 Göttingen, Germany.
Department of Molecular Structural Biology, Institute of Microbiology & Genetics, GZMB, Georg-August-University Göttingen, Justus-von-Liebig-Weg 11, 37077 Göttingen, Germany.
Structure. 2018 May 1;26(5):785-795.e4. doi: 10.1016/j.str.2018.03.004. Epub 2018 Mar 29.
Recent advances in instrumentation and image-processing software have resulted in a resolution revolution in cryo-electron microscopy (cryo-EM) and a surge in the popularity of this technique. However, despite technical progress and hundreds of structures determined so far, development of standards assessing the agreement between the cryo-EM map and the respective model has fallen behind. Here we establish a validation procedure evaluating this agreement and applied it to a set of 565 cryo-EM structures. Analysis of the results revealed that three-quarters of the validated structures exhibit moderate or low agreement between the map and the corresponding model, mostly due to limited structural features possessed by these maps. Model re-refinement significantly improved the agreement for only one-fifth of the structures, reaffirming the necessity to re-evaluate map resolution. The presented procedure provides an approach to re-estimate the resolution of cryo-EM map areas interpreted by the model.
近年来，仪器设备和图像处理软件的进步使得低温电子显微镜（cryo-EM）的分辨率发生了革命性的变化，该技术也因此得到了广泛的应用。然而，尽管取得了技术上的进步，并解析了数百个结构，但是用于评估低温电镜重构图和相应模型之间一致性的标准的发展却相对滞后。在这里，我们建立了一个验证程序来评估这种一致性，并将其应用于一组 565 个 cryo-EM 结构。对结果的分析表明，在经过验证的结构中，有四分之三的结构在重构图和相应模型之间表现出中等或低的一致性，这主要是由于这些重构图的结构特征有限。只有五分之一的结构通过重新调整模型能够显著提高一致性，这再次证实了重新评估重构图分辨率的必要性。本文提出的方法为重新估计模型解释的 cryo-EM 重构图区域的分辨率提供了一种途径。
