VIRION
Enveloped, 30-35 nm in diameter. Each segment can be packaged separately, in a multicomponent viral system. 
GENOME
Segmented linear ssRNA(+) genome with a total length of approximately 7.8 kb. The 5' RNA may be capped, as the virus encodes an MTase similar to a flavivirus.
GENE EXPRESSION
Virion RNAs are infectious and serve as both genomes and viral messenger RNAs.
ENZYMES
REPLICATION
- Attachement of the viral envelope protein E to host receptors mediates internalization into the host cell.
- Fusion of virus membrane with host membrane. RNA genome is released into the cytoplasm.
- The positive-sense genomic ssRNA are translated.
- Replication takes place presumably in cytoplasmic viral factories. dsRNA segments are synthesized from the genomic ssRNA(+).
- The dsRNA segments are transcribed/replicated thereby providing viral mRNAs and new ssRNA(+) genomes.
- Virus assembly: The virion buds and exits the cell.