Cystovirus | |
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Virus classification | |
Group: | Group III (dsRNA) |
Family: | Cystoviridae |
Genus: | Cystovirus |
Type Species | |
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Cystovirus is a genus of viruses, in the family Cystoviridae. Pseudomonas syringae pathovar phaseolicola bacteria serve as natural hosts. There is currently only one species in this genus: the type species Pseudomonas phage φ6.
Group: dsRNA
Cystoviruses[1] are distinguished by their tripartite dsRNA genome, totaling ~14 kb in length and their protein and lipid outer layer. No other bacteriophage has any lipid in its outer coat, though the Tectiviridae and the Corticoviridae have lipids within their capsids.
Most identified cystoviruses infect Pseudomonas species, but this is likely biased due to the method of screening and enrichment. The type species is Pseudomonas phage phi6, but there are many other proposed members of this family. Pseudomonas phage φ7, φ8, φ9, φ10, φ11, φ12, and φ13 have been identified and named, but other cystovirus-like viruses have also been isolated. These seven putative relatives are classified as either close (φ7, φ9, φ10, φ11) or distant (φ8, φ12, φ13) relatives to φ6, with the distant relatives thought to infect via the LPS rather than the pili.
Members of the Cystoviridae appear to be most closely related to the Reoviridae, but also share homology with the Totiviridae. In particular, the structural genes of Cystoviruses are highly-similar to those used by a number of dsRNA viruses that infect eukaryotes.