Can Taq use RNA as a template?

[KIM]

Greg Appleyard <greg.appleyard at usask.ca> wrote:
: In article <7rb5fb$det$1 at nnrp1.deja.com>, 
: nicholas_theodorakis at urmc.rochester.edu says...

[omitted stuff]

: Tim Fitwater of NeXstar Pharmaceuticals (Gilead Sciences)
: wrote an Email reply with this reference:

: M. D. Jones and N. S. Foulkes, 1989.  Reverse Transcription of mRNA by 
: Thermus aquaticus DNA polymerase. Nucleic Acids Res. 17(20):  8387-8388.


Ok, I looked at this reference.  The claim is made that Taq polymerase can
reverse transcribe at a temperature of 68 C for 30 minutes, and the
optimal Mg++ concentration is 2 - 3 mM.

So, why don't we all use thermostable polymerases as reverse
transcriptases?  Are they not processive enough or something?

Daniel Kim
dkim at nmsu.edu