Frontiers in Cryo Electron Microscopy of Complex Macromolecular Assemblies.

Area of Science:

• Structural Biology
• Biophysics
• Cell Biology

Background:

• Cryo electron microscopy (cryo-EM) has undergone significant technological advancements.
• Improvements in instrumentation, detectors, specimen preparation, and software have enhanced cryo-EM capabilities.

Purpose of the Study:

• To review recent progress in cryo-EM methods and their applications.
• To highlight the potential of cryo-EM for solving complex structural biology challenges.

Main Methods:

• Single-particle cryo-EM for high-resolution protein structure determination.
• Electron tomography combined with subvolume averaging for visualizing macromolecular complexes in situ.

Main Results:

• Achieved resolutions of ~2 Å for proteins smaller than 100 kDa using single-particle cryo-EM.
• Enabled visualization of macromolecular complexes in native environments with unprecedented detail via electron tomography.

Conclusions:

• Cryo-EM is overcoming previous limitations in structural and cell biology.
• The technology facilitates the study of dynamic protein complexes and protein aggregates, with recent examples including G protein-coupled receptors, spliceosomes, and fibrillar specimens.