Chapter 58 - Biology and Pathogenesis of Satellite Viruses

Abstract

Satellite viruses (SVs) are subviral pathogens that are entirely dependent upon the replication machinery of their helper viruses. There are only four known plant SVs: satellite tobacco necrosis virus, satellite tobacco mosaic virus, satellite panicum mosaic virus, and satellite maize white line mosaic virus. These SVs have positive-sense single-stranded RNA genomes of 800–1400nt that are encapsidated within ~17-nmT=1 icosahedral virions. SVs, in contrast to satellite-RNA or -DNA, encode a capsid protein for independent genome packaging of the cognate SV RNA. The unusually small and compact nature of these subviral agents has resulted in their use as models for fundamental virology studies, including gene expression, genome packaging, and virion structure.