The structure of the bacteriophage PRD1 spike sheds light on the evolution of viral capsid architecture.
Merckel, M.C., Huiskonen, J.T., Bamford, D.H., Goldman, A., Tuma, R.(2005) Mol Cell 18: 161-170
- PubMed: 15837420 
- DOI: https://doi.org/10.1016/j.molcel.2005.03.019
- Primary Citation of Related Structures:  
1YQ5, 1YQ6, 1YQ8 - PubMed Abstract: 
Comparisons of bacteriophage PRD1 and adenovirus protein structures and virion architectures have been instrumental in unraveling an evolutionary relationship and have led to a proposal of a phylogeny-based virus classification. The structure of the PRD1 spike protein P5 provides further insight into the evolution of viral proteins. The crystallized P5 fragment comprises two structural domains: a globular knob and a fibrous shaft. The head folds into a ten-stranded jelly roll beta barrel, which is structurally related to the tumor necrosis factor (TNF) and the PRD1 coat protein domains. The shaft domain is a structural counterpart to the adenovirus spike shaft. The structural relationships between PRD1, TNF, and adenovirus proteins suggest that the vertex proteins may have originated from an ancestral TNF-like jelly roll coat protein via a combination of gene duplication and deletion.
Organizational Affiliation: 
Programme on Structural Biology and Biophysics, Institute of Biotechnology, University of Helsinki, P.O. Box 65, Viikinkaari 1 00014, Finland.