Tungrovirus

VIRION

Non enveloped, bacilliform particles of 130 x 30 nm. The capsid is presumably based on a T=3 icosahedral symmetry.

GENOME

Circular double stranded DNA of about 8000 base pairs with discontinuities in both strands: one in the transcribed strand and one to three in the non-transcribed strand.

GENE EXPRESSION

ORF2 and ORF3 are expressed by leaky scanning of genomic RNA.

REPLICATION

CYTOPLASMIC NUCLEAR

1. Attachment of the viral proteins to host receptors mediates its entry into the host cell.
2. The viral dsDNA is released into the nucleus where it is transcribed by host RNA polymerase II
3. RNA translation produces viral proteins.
4. Genomic RNA is retrotranscribed in the cytoplasm into new dsDNA genomes
5. Genomes are encapsidated with capsid protein, releasing new virions.