PROFILE.


This blog is proudly run by two girls :

- Nur Rashilah &
- Tan Him Gee

of MB0801, Nanyang Polytechnic ;
School of Chemical & Life Sciences
:)


CONTENTS.

- Formal Welcome
- First Scoop To Virology
- Viral Replication Strategies
- Viral Replication Animation
- Viral Genetics
- Viroids & Prions
- Virusoids
- Baltimore Classification


 CREDITS.

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Virusoids.


Virusoids are satellite, viroid-like molecules, somewhat larger than viroids (e.g. approximately 1000nt) which are dependent on the presence of virus replication for multiplication (hence 'satellite'), they are packaged into virus capsids as passengers.


  • Five virusoids are known.

  • RNA genomes are 220-338 nucleotides long, circular, single stranded and possess a ribozyme activity.

  • They can replicate in the cytoplasm using an RNAdependent RNA polymerase. This enzymatic activity is common in plants but not found in animal cells.

  • They depend on a helper virus for replication. This helper virus also encapsidates them.

  • The helper viruses for these are all members of the Sobemovirus family. An example of a "helper" virus is the subterranean clover mottle virus, which has an associated virusoid.


  • Virus enzymes may aid replication of the virusoid RNA. The virusoid is incorporated into the virus particle and transmitted as a "satellite," a separate nucleic acid not part of the viral chromosome. Replication of the helper virus is independent of the virusoid.

http://www.microbiologybytes.com/virology/Viroids.html


Satellite RNAs


- Virusoids belong to a larger group of infectious agents called satellite RNAs, found in bacteria, plants, fungi, invertebrates and vertebrates.

-Satellite genomes encode proteins, satellite viruses encode capsid proteins but are still dependent upon a helper virus for replication.

-Virusoids do not interfere with the replication of their helper virus.

-These agents (virusoids) may modify the symptoms of infection by their helper virus. They do not interfere with the replication of their helper virus and are therefore differentiated from defective interfering particles that are associated with many viral infections.

Next up will be the Baltimore Classification of viruses.

See you guys!