General
Description
Characteristics
of the Virion
The variola virion has one of the longest genomes of any virus, with 187,000
nucleotides and 200 genes. The complexity of the virus is apparent in comparing
it to the AIDS virus, which only has ten genes. The smallpox virus contains
200 distinct proteins. (15:32) (15:33)
The virion is approximately 0.2 - 0.3 microns (19:4) with
a brick-shaped exterior structure that has a diameter of about 200nm and a
crinkly, knobby surface that some experts call the mulberry of pox. (15:32) At
the center of the virion is a dumbbell-shaped core which contains the double-stranded
DNA genome.
Poxviruses are unique among DNA viruses in that they replicate in the cytoplasm
of the cell rather than in the nucleus (19:4) This is
facilitated by a variety of viral proteins produced in the host cell cytoplasm.
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