Notes on Genus: TNsatV-like satellite viruses


Type member: Tobacco necrosis satellite virus


General Description

This is the only plant infecting subgroup of the ssRNA satellite viruses. The characteristic of a satellite virus (as opposed to satellite nucleic acids) is that is encapsidated in self-encoded protein structures. The satellite viruses are associated with a taxonomically diverse group of viruses and are dependent upon them for replication. With icosahedral particles of about 17 nm diameter, these are the smallest known plant viruses.


Virions isometric (icosahedral), not enveloped, about 17 nm in diameter, consisting of 60 copies of a single protein.


Monopartite, single-stranded, positive sense RNA, 800-1250 nucleotides long. The sequences of the 3'- and 5'-termini are unrelated.

Genus Genomic Organization

The genome encodes the coat protein (17-24 kDa) and sometimes (in tobacco mosaic virus satellite) has a second open reading frame.

Type Member Genomic Organization

The RNA, about 1240 nucleotides long, has a single open reading frame that encodes the coat protein (21.7 kDa).