VIRION
Non-enveloped, T=1 icosahedral symmetry, with a diameter of about 30-32nm.
GENOME
Circular ssDNA genome (-) genome of about 3.8 kb.
The genome is replicated through double-stranded intermediates.
It may encode for 4 proteins: ORF1 (Rep protein?), ORF2, ORF3 and ORF4.
GENE EXPRESSION
The proteins are expressed by alternative splicing of pre-mRNA.
REPLICATION
NUCLEAR
- Virus penetrates into the host cell.
- Uncoating, the viral ssDNA genome penetrates into the nucleus.
- The ssDNA is converted into dsDNA with the participation of cellular factors. dsDNA transcription gives rise to viral mRNAs.
- viral mRNAs are transcribed and translated to produce viral proteins.
- Replication may be mediated by a "Rep-like" protein, and would occur by rolling circle producing ssDNA genomes.
- These newly synthesized ssDNA can either
a) be converted to dsDNA and serve as a template for transcription/replication
b) be encapsidated by capsid protein and form virions released by cell lysis.
