Virus evolution: how does an enveloped virus make a regular structure?

摘要: The evolution of viruses has been an exciting area study, albeit that is fraught with difficulties be- cause the lack a fossil record and because rapid sequence divergence exhibited by viruses. All in collections available for study laboratory have isolated within last 70 years. Studies rate over this period time, all which focused on RNA viruses, given estimates 10^2 to 10^4 changes per nucleotide year (Takeda et al., 1994; Weaver 1997). Although these rates fixation mutations necessity assay only most variable positions viral genome, there are clearly change much more slowly, it nonetheless clear difficult establish relationships between two had common ancestor, example, million years ago, based solely relation- ships. Furthermore, become increasingly decades extensive recombination ages complicated evolutionary among belonging different families (Strauss 1996). To ascertain distant structural studies increasing importance, structure protein less rapidly than does amino acid forms (Rossmann 1974).