Reverse transcriptase

[Patrick O'Neil]

On Mon, 15 May 1995, Paul Schauble wrote:

> > 
> > Reverse transcriptase's whole purpose in life is to produce a dsDNA copy 
> > of a virus' RNA genome.  It has nothing to do with integration into host 
> > DNA.  It is also the primary source of mutation in viruses that use it - 
>
> But why is reverse transcriptase in the cell in the first place? What 
> function does it serve in a normal, healthy cell?

Reverse transcriptase is a virally encoded enzyme that is packaged with 
the viral genome.  When a budded virion encounters another cell and dumps 
its capsid into the cytosol, the RT becomes active.  Integrase is a 
separate virally encoded protein that incorporates the newly produced 
dsDNA genome into a host chromosome.  

Patrick