A new cryo-electron microscopy method to solve the structure of protein complexes in situ and its applications

Abstract 

Combining the cryo-electron tomography and sub-tomogram averaging, the state of art method is able to directly solve ribosome, a gold standard sample to a resolution beyond 4 Å in cellular environment. Although, the abundancy of ribosome is extremely high in cell, the data collection for a tomographic dataset lasted for couple of days. During to the lack of particles, after 3D classification, an average resolution of 6~7 Å was achieved in different conformations of ribosome. We have developed a new cryo-EM method to solve protein structures in cell with high throughput and high resolution. Using this method, we have determined PBS-PSI-PSII-LHCII supercomplexes and ribosome at 3.2 Å and 2.9 Å, respectively. For ribosome, we calculated 20 conformations with an averaged resolution beyond 4 Å. This talk will be also about the fundamental theory and the application range of the new method.

About the speaker 

Xinzheng Zhang, Institute of Biophysics, Chinese Academic of Science, Principal Investigator. Xinzheng got his Ph.D degree in Physics on 2008, supervised by Prof. Dapeng Yu. He went to Purdue University, United of States on 2009 as a post-doc to study the 3D structure of viruses with Prof. Michael G Rossmann. Xinzheng returned back to China on 2014 and started to lead an independent research group in Institute of Biophysics. He focused on developing of cryo-EM technologies, including single particle reconstruction method, cryo-EM sample freezing methods and cryo-EM method to solve the protein structure in vivo. In the recent years, Xinzheng published his works on journals such as Nature, Science, Cell, Cell Research and Nature Communications as a corresponding or co-corresponding author.