5' end of gene

Brian Smith-White smithwhi at students.msu.edu
Sun Mar 13 18:29:00 EST 1994


In Article <2lvarq$1f4 at tamuts.tamu.edu> "sac5001 at tamuts.tamu.edu (Scott Alexander Coonrod)" says:
> I have a simple question that no one to date has been able
> answer adequately. When one talks about the 5' end of a gene
> they are referring to the end at which the promoter and other
> regulatory regions are located. It is the starting point for
> transcription. When you look at any freshman biology book it
> clearly shows that both DNA and RNa polymerases can only 
> bind to the 3' end and move in the 5' direction on the template.
> It therefore makes a transcript in the 5' ---> 3' direction. 
> Why then do we not refer to the front of the gene as the
> 3'end because thats where transcription starts. Im sure
> there must be a simple answer to this question but I havent
> found it yet. Any help would be appreciated.
> 				Regards, Scott C
> 
The nomenclature of landmarks for genes is in relation to the mRNA (cDNA in
modern vocabulary). The gene proceeds from the 5' end of the message to the 
3' end. Therefore the promoter is upstream of the 5' end of the message. This
sentence is reduced in laboratory jargon to "the 5' end of the gene". If you 
get confused about this, what will happen when you encounter the problem of
two meanings for "sense strand"?
Regards,		Brian



More information about the Bioforum mailing list