Notes on Family: Avsunviroidae
Viroids are small circular ssRNA molecules, which cause virus-like diseases of plants. There are two families and this one contains those (few) viroids that lack a central conserved region (CCR) and which have the ability to self-cleave in vitro
and very probably in vivo
, through hammerhead structures.
There are no virions.
Circular, ssRNA, consisting of 240-340 nucleotides. Secondary structure predictions suggest that they exist either as rod-shaped molecules with regions of base-pairing, interspersed with hairpin loops or adopt branched configurations. No peptides are encoded by the genome.
Genera in the Family
- Avsunviroid (rod-shaped, unstable hammerhead ribozymes and 38% G+C)
- Elaviroid (rod-shaped, stable hammerhead ribozymes and >50% G+C)
- Pelamoviroid (branched, stable hammerhead ribozymes and >50% G+C)