Application of genome sequence information in potyvirus taxonomy: an overview
The application of protein and nucleic acid sequence analysis in evolutionary and phylogenetic studies is well established. Available sequence information for the 5′ untranslated region of potyviruses including the fungus-transmitted barley yellow mosaic virus (BaYMV) RNA-1 suggests that a 12-nucleotide conserved sequence, the “potybox” is unique to this group. Various non-structural proteins of potyviruses share considerable “signature” sequence homology across a broad spectrum of unrelated viruses, which makes their value limited to “supergroup” or “superfamily” identity. However, in potyviruses, the coat-protein N-terminal sequences and 3′ noncoding regions are variable among viruses, but similar among strains of the same virus. This suggests that these sequences may be an accurate marker of genetic related-ness. Until complete genome sequences from a large number of potyviruses become available and their value in systematics is tested, coat protein and 3′ noncoding regions remain as the choice of taxonomic indicators. The reason being, that cloning and sequencing of the coat-protein gene and 3′ noncoding regions are less complicated and time consuming and the sequences show significant differences among the virus species within the family Potyviridae.
KeywordsCoat Protein Tobacco Etch Virus Cylindrical Inclusion Wheat Streak Mosaic Virus Helper Component
Unable to display preview. Download preview PDF.
- 15.Gorbalenya AE, Blinov VM, Donchenko AP, Koonin EV (1988) An NTP-binding motif is the most conserved sequence in a highly divergent monophyletic group of proteins involved in positive strand RNA viral replication. J Mol Evol 28: 258–268.Google Scholar
- 25.Matthews REF (1982) Classification and nomenclature of viruses. Fourth report of the International Committee on Taxonomy of Viruses. Intervirology 17: 1–199.Google Scholar
- 27.Salomon R, Raccah B (1990) The role of the N terminus of potyvirus coat protein in aphid transmission. In: VIIIth International Congress for Virology, Berlin, August 26–31, 1990, Abstract P 83–7.Google Scholar