Cryo-electron microscopy reveals the functional organization of an enveloped virus, Semliki Forest virus

Mol Cell. 2000 Feb;5(2):255-66. doi: 10.1016/s1097-2765(00)80421-9.


Semliki Forest virus serves as a paradigm for membrane fusion and assembly. Our icosahedral reconstruction combined 5276 particle images from 48 cryo-electron micrographs and determined the virion structure to 9 A resolution. The improved resolution of this map reveals an N-terminal arm linking capsid subunits and defines the spike-capsid interaction sites. It illustrates the paired helical nature of the transmembrane segments and the elongated structures connecting them to the spike projecting domains. A 10 A diameter density in the fusion protein lines the cavity at the center of the spike. These clearly visible features combine with the variation in order between the layers to provide a framework for understanding the structural changes during the life cycle of an enveloped virus.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Cryoelectron Microscopy
  • Image Processing, Computer-Assisted
  • Models, Molecular
  • Models, Structural
  • Nucleocapsid / ultrastructure*
  • Semliki forest virus / ultrastructure*

Associated data

  • PDB/1DYL