Ministry of Education Key Laboratory of Protein Sciences, Beijing Advanced Innovation Center for Structural Biology, Beijing Frontier Research Center of Biological Structures, School of Life Sciences, Tsinghua University, Beijing, 100084, China.
Tsinghua-Peking Joint Center for Life Sciences, Tsinghua University, Beijing, 100084, China.
Nat Commun. 2019 Jun 3;10(1):2386. doi: 10.1038/s41467-019-10368-w.
The fast development of single-particle cryogenic electron microscopy (cryo-EM) has made it more feasible to obtain the 3D structure of well-behaved macromolecules with a molecular weight higher than 300 kDa at ~3 Å resolution. However, it remains a challenge to obtain the high-resolution structures of molecules smaller than 200 kDa using single-particle cryo-EM. In this work, we apply the Cs-corrector-VPP-coupled cryo-EM to study the 52 kDa streptavidin (SA) protein supported on a thin layer of graphene and embedded in vitreous ice. We are able to solve both the apo-SA and biotin-bound SA structures at near-atomic resolution using single-particle cryo-EM. We demonstrate that the method has the potential to determine the structures of molecules as small as 39 kDa.
单颗粒低温电子显微镜（cryo-EM）的快速发展使得在~3Å分辨率下获得分子量高于 300 kDa 的良好 behaved 大分子的 3D 结构变得更加可行。然而，使用单颗粒 cryo-EM 获得小于 200 kDa 的分子的高分辨率结构仍然是一个挑战。在这项工作中，我们应用 Cs 校正器-VPP 耦合 cryo-EM 来研究在薄石墨烯层上支撑并嵌入玻璃态冰中的 52 kDa 链霉亲和素（SA）蛋白。我们能够使用单颗粒 cryo-EM 解决 apo-SA 和生物素结合的 SA 结构的近原子分辨率。我们证明该方法有可能确定小至 39 kDa 的分子的结构。
