Reverse transcriptase

[Patrick O'Neil]

On 24 May 1995, Ed Rybicki wrote:

> > You are correct, it would be ridiculous for the cell to have reverse 
> > transcriptase around-
> 
> Really?  Funny, that - E coli strains and a number of other related 
> bacteria (as well as some Archaea) have reverse transcriptases as 
> part of VERY strange little retrotranspoable elements.  And 
> retroposons, etc - which are not very retrovirus-like - also have 
> reverse transcriptases.

Except that most retroelements ARE very retrovirus-like, some encoding
gag, pol and other genes in the same order as they are in full
retroviruses.  The retroelements are considered old, defective viral
units, in any case.  They would then not be part of the original bacterial
genome, but riders that came along later and now, with the loss of ability
(or need) to encode capsid and bud (or lyse) the cell, can now be
considered a permanent fixture within the bacterial genome...hence, they
have become natural parts of the bacterial genome. 


Patrick
Patrick at corona.med.utah.edu