Question

What are prions, viroids and viroins? How do virusoids differ from satellite viruses?

Answer 1

Prions are the proteinaceous infective particles that lack any nucleic acid & that can fold in multiple, structurally abstract ways, at least one of which is transmissible to other prion proteins. They are not considered viruses because they do not have any DNA or RNA.

Viroids are extremely smallest infective pathogens & they are circular pieces of infections RNA. they are only pathogenic in plants.

Virion is entire virus particle. Its an extracellular virus consisting of a protein coat (capsid) surrounding a nucleic acid core, (DNA or RNA), together known as a nucleocapsid called an envelope.

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Virusoids are single-stranded RNAs which are circular, dependent on plant viruses for replication and encapsidation

Satellite viruses are particles that contain nucleic acid genomes encoding a structural protein that encapsidates the satellite genome

The virusoids genome consist of several hundred nucleotides and does not code for any proteins. Satellite genome do not encode capsid protein, but are packaged by a protein encoded in the helper virus genome.

Viroids are autonomous & can replicate by itself; satellites require a helper virus.

Viroids has circular RNA genome; satellites do not have it.