Which strand does T7 RNA pol transcribe from?

Gordon Munro g_munro at globalnet.co.uk
Mon Mar 10 05:46:12 EST 1997

A simple enough question,  but one which is causing me some bother! 

 I have a double stranded DNA molecule about 150 bases in length.
The problem is that the two strands are only complimentary for the
first 60 or so bases.   At the 5' end of the sense strand I have a T7
RNA Pol promoter sequence.  My question is: upon introduction of T7
RNA Pol which strand is the template for the RNA Pol - the strand
containing the promoter sequence or the strand containing the
complement of the promoter sequence? 

 My understanding of the situation is that the RNA pol uses the
antisense strand as the template (i.e. the strand with the sequence
complimentary to the promoter sequence). Therefore the rna generated
will  be the compliment of the antisense strand.   Therefore when the
sequences are no longer complimentary (after about 60 bases) the rna
generated will continue to be the compliement of the antisense strand
and will include the sequence unique to the antisense strand.

Am i correct?

Any help is appreciated.


Gordon Munro            email:  g_munro at globalnet.co.uk
Cytocell Ltd

visit our website:  http://www.cytocell.co.uk

Opinions expressed are my own and not necessarily those of Cytocell Ltd.

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