Cryo-EM – from niche method towards new era in structural biology

Venue: Gamma 2, conference room, SciLifeLab in Stockholm

Presenters: Marta Carroni and Alexey Amunts

Using the most recent advances in cryo-EM it is now possible to resolve protein complexes within a range of 170 kDa – 3 MDa to ~3 Å resolution or better. At this level, the obtained density maps allow de novo model building of atomic models, including water molecules, ions and even some post-translational modifications. The main advantages of the technique are: 1) relatively small amounts of material consumed (up to four orders of magnitude less then for X-ray crystallography); 2) no prior crystallization is required; 3) computational algorithms allowing separation of multiple protein conformations through in silico classification; 4) pure maps can be obtained for samples even with a degree of contamination. In the talk, this will be exemplified by the structures of yeast and human mitochondrial ribosomes that had been intractable for X-ray crystallography for decades, and resolved by cryo-EM.