Friday, January 2, 2015
“3Cryo-EM for Structural Biology and DNA Nanotechnology”
Tong Wang, Brookhaven National Laboratory
I will give two examples to demonstrate the application of single particle cryo-EM in structural biology and DNA nanotechnology. The first example will be a cryo-EM investigation of the prokaryotic proteasomal activation by a novel cofactor in an ATP-independent manner. At an intermediate resolution, I showed that the cofactor enlarges the substrate entrance of prokaryotic proteasome core particles. Additionally, I identified the cofactor-binding site on the proteasomes. The second example will be a visualization of 3D architectures inside inorganic metal nanoparticle clusters that are organized by a robust designer DNA frame. DNA-templated self-assembly is an efficient way to achieve programmable spatial arrangement of nanostructured clusters, such as nanoparticles. However self-assembled 3D architectures are difficult to characterize; I show that cryo-EM is an ideal tool to address this challenge, because it is capable of obtaining high-resolution 3D structures with minimal structural disturbance. By adapting the existing computational image processing methods, I found that cryo-EM should be a very useful tool for characterizing 3D bio-hybrid systems in the future.