Challenges in Cryo-Tomography
Structural biologists have made great progress in unraveling the structures of individual proteins and protein complexes. Much of these recent results have been made using Single Particle Analysis (SPA), which has turned 3D reconstructions of protein (complexes) into an almost routine technique.
While SPA solves the structure of highly
purified proteins, Cryo-ET opens windows into cells, allowing a molecular view
of proteins in their native environment.
The ultimate goal for these structural and cell biologists is to derive the structures of molecular machineries of all living systems within their natural, functional contexts, where their interactions with other components can be observed.
Cryo-TEM advantages:
- Allow for nanometer-scale 3D models of biological structures in their native, cellular context
Visualization of the nuclear periphery of a HeLa cell revealed by cryo‐electron tomography. The interphase HeLa cellwas thinned by cryo‐focused ion beam (cryo‐FIB) milling. The 3D segmentation of the tomographic data shows microtubules (orange), actin
filaments (yellow), endoplasmic reticulum (green), nuclear pore complexes (light blue),large (dark blue) and small (brown) ribosomal subunits.
Data courtesy of Dr. J. Mahamid, Department of Molecular Structural Biology, Max Planck Institute for Biochemistry,Martinsried, Germany.