300 keV FEG Electron Cryo Microscope for Single Particle Analyses

Deutsche Forschungsgemeinschaft (DFG) - Projektnummer 342246990

Single particle electron cryo microscopy (cryoEM) enables structural analyses of the macromolecular building blocks of cells. Probing structure-function relationships is essential for understanding basic molecular mechanisms in biology. We here aim to analyse in detail macromolecules and their dynamic changes in the course of infections – a major research focus in Hamburg. The technical advancements and break troughs of the recent years have moved the technology to a state allowing to achieve routinely three-dimensional structures in a resolution range between 2.5 und 6Å for stable protein complexes. This ‚revolution’ is based on the following factors: (1) development of robust 300keV high-resolution electron cryo microscopes with parallel illumination and robotic sample handling, (2) introduction of direct electron detectors, (3) automated data acquisition software, (4) more robust and versatile analysis software packages and (5) better computing hardware. Together these developments have moved single particle cryoEM to an efficient and crystallisation independent alternative for high-resolution structural analyses of biological macromolecules. In particular for larger more flexible macromolecular complexes with various functional conformations single particle cryoEM in combination with robust classification algorithms provides a highly attractive approach in structural biology. Demand for respective cryoEM access has risen immensely and includes now communities beyond ‘classical’ structural biologists, like biochemist and cell biologists (cf. the broad user base of the instrument).