Authors: Xiao Fan, Jia Wang, Xing Zhang, Zi Yang, Jin-Can Zhang, Lingyun Zhao, Hai-Lin Peng, Jianlin Lei, Hong-Wei Wang
Published: 2019-06-03
DOI: 10.1038/s41467-019-10368-w
Source: Full article
AbstractThe 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.