The Advanced Cryo-Electron Microscopy Technology Group explores emerging imaging platforms and develops methodologies, focusing on projects with the potential to make cryo-EM a more widely accessible technique. The team focuses on single-particle analysis and cryo-electron tomography. 

Pushing resolution limits 

Our group aims to push resolution limits on our 200 kV CryoARM microscope to compare its performance to the more popular 300 kV microscopes. Our structure-determination methods are initially developed on standard cryo-EM specimens, such as beta-galactosidase, and later applied to more biologically relevant samples, especially where high-resolution information is needed to provide mechanistic insights. Ultimately, the goal is to sufficiently streamline the process to efficiently obtain high-resolution cryo-EM structures for a broad range of targets.

We work with the National Cryo-Electron Microscopy Facility to improve its services and support provided to the research community. 

 

Structure-guided drug design

Cryo-EM approaches atomic resolution

Structure of Escherichia coli β-galactosidase determined at a resolution of ∼1.8 Å.
Implications for RAS cancers

Untangling the complex genetics of neurofibromatosis

Neurofibromatosis linked to destabilization of NF1 protein dimers.

Development and application of cryo-EM methods 

We push the resolution and size limits of the cryo-EM technique and optimize the workflows, so they are suitable for challenging, medically important specimens.  

Imaging protein complexes 

In a collaboration with an external partner, we develop optimized data collection procedures for the CryoARM microscope. These procedures were used to obtain a 1.8Å structure of beta-glactosidase, which was published in the journal IUCrJ in 2020.  Further improvements to the process produced a 1.6Å structure of the same sample.  

1.6 Å cryo-EM structure of b-galactosidase obtained using CryoARM200 equipped with a K3 camera. 

Our capabilities and specializations

Regulation of gene expression 

Apply single-particle cryo-EM to explore the structural determinants of the regulation of gene expression. 

  • Transcription-factor specificity  

  • Cis-acting regulatory elements  

  • Effects of chemical modifications 

Molecular mechanisms of signaling 

Combine information from cryo-electron tomography and single-particle analysis to gain insights into molecular mechanisms of signaling. 

  • Protein-protein interactions  

  • Transmembrane signal transduction  

  • Cell-cell communication 

Chemistry and dynamics of enzyme catalysis 

Use high-resolution structures and emerging computational methods for analyzing conformational heterogeneity to study the chemistry and dynamics of enzyme catalysis. 

  • Roles of metals in enzyme activity  

  • Conformational landscapes of enzymes  

  • Allosteric regulation 

Human ribosome seen at atomic level
Viewing DNA

Human ribosome seen at atomic level

This snapshot captures a detailed view of Watson-Crick base pairing between adenine and thymine nucleotides within a 1.7Å cryo-EM map of the human ribosome. This map was obtained using the CryoARM200 microscope. The green mesh highlights positive difference map peaks, revealing the presence of hydrogen atoms.
1.8 Å resolution cryo-EM map of a 145 kDa cancer-related protein
High resolution

Protein structural biology revealed

A wealth of structural information is visible in a 1.8 Å resolution cryo-EM map of a 145 kDa cancer-related protein. Hydrogen atoms are depicted in the difference map (highlighted in green mesh).