Satellite virus: The virus needs a helper virus for viral replication. Infection requires host cell to be co-infected with a virus from the genus Tobamovirus.
VIRION
Non-enveloped, spherical, T=1 icosahedral capsid, about 17 nm in diameter. Sixty copies of the capsid protein form the capsid.
GENOME
Linear, ssRNA(+) genome of about 1 kb, which lacks a cap structure and a poly(A)tail.
GENE EXPRESSION
The virion RNA is infectious and serves as both the genome and viral messenger RNA. Encodes one capsid protein and an unknown ORF.
ENZYMES
- None
REPLICATION
CYTOPLASMIC
- Virus penetrates into the host cell.
- Uncoating, and release of the viral genomic RNA into the cytoplasm.
- The viral RNA is translated to produce the capsid protein.
- Replication takes place in cytoplasmic viral factories. A dsRNA genome is synthesized from the genomic ssRNA(+).
- The dsRNA genome is transcribed/replicated thereby providing viral mRNAs/new ssRNA(+) genomes.
- Virus assembly.
- Virus release.