[khurrum (OP)]

Hi people....
can anyone tell me that how the transcription bubble remain open durng the whole process 
though i undrstnd it is becase of RNA polymerase but m not nfrmed    [:-[]about it so plz guide me....

[DrN]

Think of it as a zipper - the bubble is held open by the bit that you pull, but it moves down the entire length of the zip as you pull it along.

In the same way, the transcription bubble does appear to stay open as it moves down the DNA, but in fact it is continuously reforming throughout the entire length of the transcribed DNA. The transcriptional machinery - the protein 'blob' keeping the DNA strands apart - unwinds the DNA in front of it (like a zipper separates the teeth of a zip), allowing it to move forward, and simultaneously re-winds the DNA behind it again (like the teeth of the zipper becoming interlocked again). 

Look at the 'elongation' section of the wikipedia entry

http://en.wikipedia.org/wiki/Transcription_(genetics)

[khurrum (OP)]

ok thnkx  []
but can i got ths point as "RNA polymerase has not major role in keepng the transcrptn buble remain open" ??
and u write protein "blob" wht kind of protn it z???
   
      khurrum