GENE EXPRESSIONThe virion RNA is infectious and serves as both the genome and viral messenger RNA. ORF 1 encodes the nonstructural proteins, it is not clear whether this polyprotein is cleaved or not; ORF 2 encodes the capsid protein; ORF 3 encodes a small immunogenic protein. ORF2 is translated by leaky scanning from the bicistronic ORF3-2 subgenomic RNA.