4v1w
From Proteopedia
3D structure of horse spleen apoferritin determined by electron cryomicroscopy
Structural highlights
FunctionFRIL_HORSE Stores iron in a soluble, non-toxic, readily available form. Important for iron homeostasis. 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 PubMedDespite recent advances, the structures of many proteins cannot be determined by electron cryomicroscopy because the individual proteins move during irradiation. This blurs the images so that they cannot be aligned with each other to calculate a three-dimensional density. Much of this movement stems from instabilities in the carbon substrates used to support frozen samples in the microscope. Here we demonstrate a gold specimen support that nearly eliminates substrate motion during irradiation. This increases the subnanometer image contrast such that alpha helices of individual proteins are resolved. With this improvement, we determine the structure of apoferritin, a smooth octahedral shell of alpha-helical subunits that is particularly difficult to solve by electron microscopy. This advance in substrate design will enable the solution of currently intractable protein structures. Electron microscopy. Ultrastable gold substrates for electron cryomicroscopy.,Russo CJ, Passmore LA Science. 2014 Dec 12;346(6215):1377-80. doi: 10.1126/science.1259530. PMID:25504723[1] From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. See AlsoReferences
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