We apologize for Proteopedia being slow to respond. For the past two years, a new implementation of Proteopedia has been being built. Soon, it will replace this 18-year old system. All existing content will be moved to the new system at a date that will be announced here.

8hhs

From Proteopedia

Jump to: navigation, search

Structure of human apoferritin embedded in crystalline ice

Structural highlights

8hhs is a 24 chain structure with sequence from Homo sapiens. Full crystallographic information is available from OCA. For a guided tour on the structure components use FirstGlance.
Method:	Electron Microscopy, Resolution 2.4Å
Resources:	FirstGlance, OCA, PDBe, RCSB, PDBsum, ProSAT

Function

FRIH_HUMAN Stores iron in a soluble, non-toxic, readily available form. Important for iron homeostasis. Has ferroxidase activity. Iron is taken up in the ferrous form and deposited as ferric hydroxides after oxidation. Also plays a role in delivery of iron to cells. Mediates iron uptake in capsule cells of the developing kidney (By similarity).

Publication Abstract from PubMed

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.

Addressing compressive deformation of proteins embedded in crystalline ice.,Shi H, Wu C, Zhang X Structure. 2023 Feb 2;31(2):213-220.e3. doi: 10.1016/j.str.2022.12.001. Epub 2022 , Dec 30. PMID:36586403^[1]

From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.

References

↑ Shi H, Wu C, Zhang X. Addressing compressive deformation of proteins embedded in crystalline ice. Structure. 2022 Dec 14:S0969-2126(22)00487-7. doi: 10.1016/j.str.2022.12.001. PMID:36586403 doi:http://dx.doi.org/10.1016/j.str.2022.12.001