8HHS

Structure of human apoferritin embedded in crystalline ice

Summary for 8HHS

• Entry DOI: 10.2210/pdb8hhs/pdb
• EMDB information: 32703
• Descriptor: Ferritin heavy chain (1 entity in total)
• Functional Keywords: metal binding protein
• Biological source: Homo sapiens (human)
• Total number of polymer chains: 24
• Total formula weight: 482797.13

Authors

Shi, H.,Wu, C.,Zhang, X. (deposition date: 2022-11-17, release date: 2023-02-15, Last modification date: 2024-07-03)

Primary citation

Shi, H.,Wu, C.,Zhang, X.
Addressing compressive deformation of proteins embedded in crystalline ice.
Structure, 31:213-220.e3, 2023

PubMed Abstract: For cryoelectron microscopy (cryo-EM), high cooling rates have been required for preparation of protein samples to vitrify the surrounding water and avoid formation of damaging crystalline ice. Whether and how crystalline ice affects single-particle cryo-EM is still unclear. Here, single-particle cryo-EM was used to analyze three-dimensional structures of various proteins and viruses embedded in crystalline ice formed at various cooling rates. Low cooling rates led to shrinkage deformation and density distortions on samples having loose structures. Higher cooling rates reduced deformations. Deformation-free proteins in crystalline ice were obtained by modifying the freezing conditions, and reconstructions from these samples revealed a marked improvement over vitreous ice. This procedure also increased the efficiency of cryo-EM structure determinations and was essential for high-resolution reconstructions.

PubMed: 36586403
DOI: 10.1016/j.str.2022.12.001

Experimental method

ELECTRON MICROSCOPY (2.4 Å)