Institute of Science and Technology Austria, Am Campus 1, A-3400 Klosterneuburg, Austria.
Curr Opin Struct Biol. 2019 Oct;58:1-9. doi: 10.1016/j.sbi.2019.03.018. Epub 2019 Apr 18.
Cryo-electron tomography (cryo-ET) provides unprecedented insights into the molecular constituents of biological environments. In combination with an image processing method called subtomogram averaging (STA), detailed 3D structures of biological molecules can be obtained in large, irregular macromolecular assemblies or in situ, without the need for purification. The contextual meta-information these methods also provide, such as a protein's location within its native environment, can then be combined with functional data. This allows the derivation of a detailed view on the physiological or pathological roles of proteins from the molecular to cellular level. Despite their tremendous potential in in situ structural biology, cryo-ET and STA have been restricted by methodological limitations, such as the low obtainable resolution. Exciting progress now allows one to reach unprecedented resolutions in situ, ranging in optimal cases beyond the nanometer barrier. Here, I review current frontiers and future challenges in routinely determining high-resolution structures in in situ environments using cryo-ET and STA.
低温电子断层扫描（cryo-ET）为生物环境中的分子成分提供了前所未有的见解。与一种称为亚断层平均（subtomogram averaging，STA）的图像处理方法结合使用，可以在不进行纯化的情况下，在大型不规则的大分子组装体或原位获得生物分子的详细 3D 结构。这些方法提供的上下文元信息，例如蛋白质在其天然环境中的位置，然后可以与功能数据结合使用。这使得可以从分子水平到细胞水平详细了解蛋白质的生理或病理作用。尽管 cryo-ET 和 STA 在原位结构生物学中具有巨大的潜力，但它们受到方法学限制的限制，例如可获得的分辨率低。现在令人兴奋的进展允许人们在原位达到前所未有的分辨率，在最佳情况下，分辨率超过纳米级障碍。在这里，我回顾了使用 cryo-ET 和 STA 常规确定原位环境中高分辨率结构的当前前沿和未来挑战。
