Book of Abstracts: Albany 2009

category image Albany 2009
Conversation 16
June 16-20 2009
© Adenine Press (2008)

Electron Cryo-microscopy of Molecular Nanomachines and Cells

Electron cryomicroscopy (cryo-EM) is an emerging biophysical tool that can be used to determine structures of molecular nanomachines in fully solvated conformations at subnanometer resolutions (<1 nm). Such cryo-EM maps can reveal long α-helices and large β-sheets. In the highest resolution cryo-EM density maps, it is possible to see side- chains and trace the Cα backbone of protein subunits within a multi-component nanomachine. Electron cryo-tomography (cryo-ET) is equally powerful because of the unique cellular context in which it can capture and reveal cellular nanomachines. Despite reaching only 4-10 nm resolution, cryo-ET reconstructions are capable of imaging whole cells and distinguishing their molecular components. Both of these methods are complementary to conventional methods of structure determination, including X-ray crystallography and NMR spectroscopy. Hybrid methods that combine these structural techniques with cryo-EM and cryo-ET result in a complete view of nanomachines from atomic detail to their spatial and temporal location within a cell. I will describe the experimental and computational pipeline in cryo-EM and cryo-ET and illustrate their effectiveness with biological examples. Research has been supported by grants from NIH and NSF.

Wah Chiu

National Ctr for Macromolecular Imaging
Verna and Marrs McLean Dept
of Biochemistry and Molecular Biology
Baylor College of Medicine
Houston, TX 77030