The specific Cryo-Electron Microscope (cryo EM) to be acquired is a FEI Talos Arctica that is a 200 kV Transmission Electron Microscope (TEM), with a Falcon 3EC direct electron detector, and a 12 position autoloader (AL). We are seeking to acquire the Arctica for vitrification-screening of samples to queue for data collection on the one year old Titan Krios, which is fully operational although overwhelmed with samples, most of which are not ready for data collection. To obtain 3-D structures from cryoEM data, single particle reconstructions rely on collecting different two dimensional views of the same object that are then reconstructed into a 3-D map. The subjects for visualization by the users of this acquisition grant range broadly. Included are many multi-protein complexes, enzymes, DNA-protein complexes, RNA structures, and virus- receptor and virus-antibody complexes. The diversity of these projects, each chosen because of the likelihood of success showcases the powerful application of cryo-electron microscopy techniques. We identify 6 major users, 3 minor users, and 3 other users making a total of 12 labs. The projects described are ready for cryo EM and absolutely depend on vitrification-screening to succeed and proceed to data collection and data processing using single particle reconstruction approaches.
The new Talos Arctica will bring much needed vitrification screening capabilities to Penn State, enabling the ongoing research of eleven established researchers. A camera upgrade and other minor additions will also allow data collection for micro-electron diffraction that will add versatility to Penn State structural biology. The requested cryo-electron microscope will be used to investigate many important aspects of viruses, proteins, protein complexes, polymerase modulation, RNA metabolism, DNA replication complex, cell wall synthesis, transcription activation, and structure-function studies of photosystem I.
