Non-enveloped, slightly flexuous, filamentous, 640 nm or more long and 12 nm in diameter.
Linear ssRNA(+) genome of 6.5 kb in size. The 3' terminus is polyadenylated. Encodes 3 proteins.
The virion RNA is infectious and serves as both the genome and viral messenger RNA. Replication-related proteins are translated directly from the genomic RNA (ORF1). ORF2 and ORF3 are transcribed presumably as subgenomic mRNAs (sgRNAs) and respectively code for the movement and capsid protein.
- Virus penetrates into the host cell.
- Uncoating, and release of the viral genomic RNA into the cytoplasm.
- The viral RNA is translated as a monocistronic mRNA to produce the RdRp (encoded by the 5'-proximal ORF).
- Replication occurs in viral factories. A dsRNA genome is synthesized from the genomic ssRNA(+).
- The dsRNA genome is transcribed/replicated thereby providing viral mRNAs/new ssRNA(+) genomes.
- Internal subgenomic promoters are used to transcribe the sgRNAs. Traduction of these sgRNAs yields the capsid and movement proteins.
- Assembly of new virus particles.
- Movement protein allows cell-to-cell and long-distance movement.