Alphasatellitidae

Satellite virus: Replicated and packaged by helper Geminivirus (Begomoviruses or Mastrevirus ) or Nanoviruses

GENOME

Circular, single-stranded DNA genome from 1100 to 1380 nucleotides that is similar to DNA-R component of nanoviruses. Contains an adenine rich region, and a satellite conserved region (SCR).

GENE EXPRESSION

The genome encodes for a Rep protein.



h4. REPLICATION

NUCLEAR

  1. Virus penetrates into the host cell.
  2. Uncoating, the viral ssDNA genome penetrates into the nucleus.
  3. The ssDNA is converted into dsDNA with the participation of cellular factors.
  4. bidirectional dsDNA transcription from the IR promoter produces viral mRNAs and translation of viral proteins.
  5. Replication is initiated by cleavage of the(+)strand by REP, and occurs by rolling circle producing ssDNA genomes.
  6. These newly synthesized ssDNA can either
    a) be converted to dsDNA and serve as a template for transcription/replication
    b) be encapsidated by CP and form virions released from the cell by budding
    c) be transported outside the nucleus, to a neighboring cell through plasmodesmata (cell-cell movement) with the help of viral movement proteins.