Selective pressure causes an RNA virus to trade reproductive fitness for increased structural and thermal stability of a viral enzyme.
Dessau, M., Goldhill, D., McBride, R., McBride, R.L., Turner, P.E., Modis, Y.(2012) PLoS Genet 8: e1003102-e1003102
- PubMed: 23209446 
- DOI: 10.1371/journal.pgen.1003102
- Primary Citation of Related Structures:  
4DQ5, 4DQ7, 4DQJ - PubMed Abstract: 
The modulation of fitness by single mutational substitutions during environmental change is the most fundamental consequence of natural selection. The antagonistic tradeoffs of pleiotropic mutations that can be selected under changing environments therefore lie at the foundation of evolutionary biology ...