Sinhaliviridae (taxid:2732891)

VIRION

Non enveloped virion, about 30 nm in diameter with a T=3 icosahedral symmetry (180 protein subunits) or T=4 icosahedral symmetry .

GENOME

Monopartite linear, ssRNA(+) genome of about 6kbb. Each genome segment 5' end is capped. The 3'end has no poly (A) tract.

GENE EXPRESSION

The virion RNA is infectious and serves as both the genome and viral messenger RNA.

ENZYMES

• RNA-dependent RNA polymerase [RdRp]
• Alphavirus-type capping?:
  • RNA TPase [RdRp]
  • N7 MTase [RdRp]
  • GTase [RdRp]
  • 2'O MTase ?

REPLICATION

CYTOPLASMIC

1. Virus penetrates into the host cell.
2. Uncoating, and release of the viral genomic RNA into the cytoplasm.
3. The viral RNA is translated to produce virus protein.
4. Replication takes place in cytoplasmic viral factories. A dsRNA genome is synthesized from the genomic ssRNA(+).
5. The dsRNA genome is transcribed/replicated thereby providing viral mRNAs/new ssRNA(+) genomes.
6. Virus assembly in the cytoplasm around genomic RNA1 and RNA2.
7. Release of infectious particles (lysis?).

Host-virus interaction

Suppression of RNA silencing

Nodamuravirus protein B2 and Flock house virus protein B2 act as suppressors of RNA silencing .