Notes on Genus: Nanoviridae alphasatellites
no particles of their own
Type member:
Contents
General Description
Alphasatellites were first discovered in association with begomoviruses (where they were initially described as DNA-1 molecules and are classified here as
Begomovirus alphasatellites). They encode a rolling-circle replication initiator protein (Rep) and are capable of self-replication in an appropriate host but depend upon the helper virus for encapsidation and movement between plants. The related molecules described here are additional satellite components associated with viruses in the family
Nanoviridae.
Morphology
There are no distinctive virions, because the satellite DNA is encapsidated by the helper virus.
Genome
Monopartite, circular, ssDNA of 1000-1130nt.
Genus Genomic Organization
The DNA encodes a single replication initiator protein of 32-37 kDa in the virion (positive) sense. They are not officially classified by ICTV, but are here organised into "species-like" clusters within which the sequences are closely related (usually >80% nt identity) to one another.
Type Member Genomic Organization
There is no formal type member