Job Description

Project: Membrane Fusion on EM Grids

Current cryo-CLEM methods suffer from one functional weakness: they are based upon tagging a specific protein or membrane, but cannot discriminate between subgroups based on functions of interest. In the Fusion on EM Grids project, we adapted fusion assays to the conditions of cryo-CLEM in order to specifically target viruses undergoing fusion reactions. Using these assays, we can distinguish between a tight membrane apposition and hemifusion, which are not easily distinguished by electron microscopy alone.

Project: Organization of alpha-Carboxysomes

Alpha-carboxysomes are a bacterial microcompartment responsible for carbon fixation in some chemoautotrophs and cyanobacteria. They are critical for their hosts’ survival, but they can also be expressed and function in other bacteria and plant cells, and even function in vitro (outside of a cell). We have crystal structures of many of their proteins, but there are many unanswered questions about how the compartment is organized.

We performed cryo electron tomography with subtomogram averaging to look at the major enzyme cargo, Rubisco. We found that it polymerizes into long chains at high concentrations, and that those chains can arrange into a lattice. We did biophysical analyses on the data to look at binding partners, any conformational changes, interaction sites and more to understand how all of this works!