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Single particle cryo-EM reconstruction of 52?kDa streptavidin at 3.2 Angstrom resolution.

ABSTRACT: 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.

SUBMITTER: Fan X

PROVIDER: S-EPMC6546690 | biostudies-literature | 2019 Jun

REPOSITORIES: biostudies-literature

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