Imaging Biopolymers In Vivo Directly with Cryo-ET: Trim5 Nets and IRE-1 Helices

Abstract

In the last ten years electron cryotomography (cryo-ET) has made it possible to visualize large macromolecular assemblies inside intact cells in a near-native, “frozen-hydrated” state in 3-D to a few nanometers resolution. increasingly, atomic models of individual proteins and smaller complexes obtained by X-ray crystallography, NMR spectroscopy, or other methods can be fit into cryotomograms to reveal how the various pieces work together inside cells. A few good pictures is therefore sometimes all that is really needed to distinguish between competing models.