I chose to research a relatively new virus discovered in the past year. I chose the family Circoviridae particularly because of its very small genome size (between 1 and 2 Kilobases). It amazes me that a virus so small, coding for only two proteins, a replication and capsid protein can be sustained. Of course in this line toward efficiency I wanted to also investigate prions but held back for the moment at Yasser’s request.
The Dragonfly Cyclovirus is a circular ssDNA (single stranded) virus and was discovered reccently in dragonflies (Odonata: Anisoptera) in Tonga.
It is described in detail in this paper published this year (2011):
Rosario, K., Marinov, M., Stainton, D., Kraberger, S., Wiltshire, E. J., Collings, D. A., . . . Varsani, A. (2011). Dragonfly cyclovirus, a novel single-stranded DNA virus discovered in dragonflies (odonata: Anisoptera). The Journal of General Virology, 92(Pt 6), 1302-8. doi:10.1099/vir.0.030338-0
The Dragonfly Cyclovirus is the first known report of a circular ssDNA virus infecting insects. The paper suggests that this may help explain some evolutionary links between cycloviruses and circoviruses.
This virus was discovered using a “Shotgun sequencing” method from samples taken from three species of dragonflies on the Kingdom of Tonga.
While I was not able to find a complete genome with genome length, a similar virus, Cyclovirus Bat/USA, with a genome size of 1.7 Kb will have to serve as a reference point.
I was able to find an identified replication associated protein on uniprot.org:
>tr|F1CZT7|F1CZT7_9CIRC Replication associated protein
OS=Dragonfly cyclovirus PE=4 SV=1
MREATGINAGTRANALVLIRVEPVTRMRRMNITIRRFVFTWNNYTTSDFETCITFLDNFC
KYGIIGKEKCPTTQTPHIQGFCNLSKPMRFNNIKKHLHHTIHIEKANGSDEQNKIYCSKS
GEFFEKGHPDKQGKRNDLDAVVLTIQNGTNTISNVAKLHPISFIKYHKGIKEYINHVNPI
RPRHYKSEVYYYWGPPGTGKSKTALEKATAYNTDSIYYKPRGLWWDGYQQQTSVIIDDFY
GWIKYDELLKICDRYPYKVQIKGGFEEFTSKYIFITSNVDTCDLYKFRNYNTDAIERRIT
EKIHFKNIF
After doing a BLAST search in NCBI I came up with some interesting similarities:
Bat circovirus ZS/China/2011, Cyclovirus PK5006, Cyclovirus PK5034
Similarities to viruses found in other species:
Illustration from the aforementioned paper.