Cryo-electron tomography: A tool for in situ structural analysis of macromolecular complexes

Conventional techniques for structural analysis have intrinsic limitations, including damage or distortion of the functional conformation of a protein complex during purification steps. Recently, a promising electron microscopy technique, cryo-electron tomography (cryo-ET), has been used to obtain insights regarding the molecular assemblies that drive cellular processes. This review focuses on the introduction of the cryo-ET and its recent improvement of resolution, in combination with the development of hardware and software such as direct electron detectors and sub-tomogram averaging techniques. Although cryo-ET still has several challenges, it can provide a glimpse into the interaction and function of macromolecules in their native environment.