STRUCTURAL STUDIES OF VIRUSES BY ELECTRON CRYOMICROSCOPY

Electron cryomicroscopy is a unique biophysical technique for studying molecular structures of viruses which are difficult to analyze by x-r ay diffraction. The structural information derived from the low resolu tion reconstructions of viruses has so far been useful to understand v arious functional properties of the viruses such as antibody neutraliz ation, receptor binding and assembly. Electron cryomicroscopy has enab led the visualization of the four core alpha helices of the coat prote in in tobacco mosaic virus. This represents the highest resolution det ail of a virus studied by electron cryomicroscopy. The prospects of at taining similar resolution beyond 10 Angstrom for spherical viruses as well are encouraging, with newly available instrumentation, data coll ection and processing procedures.