Viroids
I. What is viroids?
- Viroids are plant-restricted parasites that represent a remarkable model system to
analyze many aspects of host-pathogen interactions at the genomic level.
- As the smallest known agents of infectious
- Structural features:
Consists of single-stranded, circular RNA
Low molecular weight RNA
Do not possess a protein or membrane shell
Their complex secondary structure they have unusual properties such as
resistance to ribonuclease digestion and denaturation
Viroids do not encode any protein
Use host end-coded polymerase for replication
Cause certain plant and human diseases and “classical” viroids have been
found only in plants.
More than 40 viroid species and many variants have been characterized
- Classification:
Pospiviroidae family (most viroids) is an acronym derived from potato
spindle tuber viroid, the representative species type. Viroids that belong to
this family adopt a quasi-rod or rod-like secondary structure, with dsRNA
regions separated by unpaired internal single-chain loops, in which five
structural domains can be distinguished.
I. What is viroids?
- Viroids are plant-restricted parasites that represent a remarkable model system to
analyze many aspects of host-pathogen interactions at the genomic level.
- As the smallest known agents of infectious
- Structural features:
Consists of single-stranded, circular RNA
Low molecular weight RNA
Do not possess a protein or membrane shell
Their complex secondary structure they have unusual properties such as
resistance to ribonuclease digestion and denaturation
Viroids do not encode any protein
Use host end-coded polymerase for replication
Cause certain plant and human diseases and “classical” viroids have been
found only in plants.
More than 40 viroid species and many variants have been characterized
- Classification:
Pospiviroidae family (most viroids) is an acronym derived from potato
spindle tuber viroid, the representative species type. Viroids that belong to
this family adopt a quasi-rod or rod-like secondary structure, with dsRNA
regions separated by unpaired internal single-chain loops, in which five
structural domains can be distinguished.
