Department of Chemistry and Biochemistry, UCLA-DOE Institute, University of California, Los Angeles, Los Angeles, CA, USA.
Department of Biological Chemistry and Department of Chemistry and Biochemistry, University of California Los Angeles (UCLA), Howard Hughes Medical Institute (HHMI), UCLA-DOE Institute for Genomics and Proteomics, Los Angeles, CA 90095, USA.
Curr Opin Struct Biol. 2017 Oct;46:79-86. doi: 10.1016/j.sbi.2017.06.004. Epub 2017 Jun 22.
It is now possible to routinely determine atomic resolution structures by electron cryo-microscopy (cryoEM), facilitated in part by the method known as micro electron-diffraction (MicroED). Since its initial demonstration in 2013, MicroED has helped determine a variety of protein structures ranging in molecular weight from a few hundred Daltons to several hundred thousand Daltons. Some of these structures were novel while others were previously known. The resolutions of structures obtained thus far by MicroED range from 3.2Å to 1.0Å, with most better than 2.5Å. Crystals of various sizes and shapes, with different space group symmetries, and with a range of solvent content have all been studied by MicroED. The wide range of crystals explored to date presents the community with a landscape of opportunity for structure determination from nano crystals. Here we summarize the lessons we have learned during the first few years of MicroED, and from our attempts at the first ab initio structure determined by the method. We re-evaluate theoretical considerations in choosing the appropriate crystals for MicroED and for extracting the most meaning out of measured data. With more laboratories worldwide adopting the technique, we speculate what the first decade might hold for MicroED.
现在可以通过电子晶体学显微镜（cryoEM）常规地确定原子分辨率结构，这在一定程度上得益于称为微电子衍射（MicroED）的方法。自 2013 年首次演示以来，MicroED 已帮助确定了各种分子量从几百道尔顿到几十万道尔顿的蛋白质结构。其中一些结构是新颖的，而另一些则是先前已知的。迄今为止，通过 MicroED 获得的结构分辨率范围为 3.2Å 至 1.0Å，大多数优于 2.5Å。MicroED 研究了各种大小和形状的晶体，具有不同的空间群对称性，并且具有不同的溶剂含量。迄今为止探索的广泛晶体为纳米晶体的结构测定提供了机会。在这里，我们总结了在 MicroED 的最初几年中以及在我们首次尝试通过该方法确定从头结构中所学到的经验教训。我们重新评估了在选择适合 MicroED 的晶体以及从测量数据中提取最有意义信息方面的理论考虑。随着全球更多的实验室采用该技术，我们推测 MicroED 的第一个十年可能会是什么样子。
