Editor's Summary

2 February 2006

Spherical virus structure

Structural determinations of spherical viruses have so far been limited to the capsid shell with icosahedral symmetry. Now for the first time an entire spherical virus structure has been determined without imposing icosahedral symmetry, a strategy that was necessary to simplify image reconstruction calculations. The virus in question is epsilon15 phage, which infects the human pathogen Salmonella anatum so is a potential therapeutic agent for salmonellosis. Single-particle cryo-electron microscopy shows the icosahedral protein shell to consist of 60 hexamers and 11 pentamers. Non-icosahedral components cluster at one of the twelve capsid vertices, through which DNA is packaged and released. The genome is packed in coaxial coils and a previously unidentified protein core wraps around the terminal end of the DNA. The shell resembles those of other dsDNA viruses including herpesvirus, suggesting a common ancestor.

Letter: Structure of epsilon15 bacteriophage reveals genome organization and DNA packaging/injection apparatus

Wen Jiang, Juan Chang, Joanita Jakana, Peter Weigele, Jonathan King and Wah Chiu

doi:10.1038/nature04487

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