You have isolated a piece of DNA that you believe contains an interesting gene.Using a mix of RNA polymerase and ribonucleotides,you perform in vitro transcription.However,even though all of your controls work,no mRNA is created from your DNA fragment.Working backward,you note that your DNA preparation removed approximately 250 base pairs from the 5' end of the gene.The most likely explanation is that during DNA preparation
A)the termination signal was removed.
B)the RNA polymerase became inactivated.
C)the 5' methyl guanosine cap was removed.
D)the promoter was removed.
E)None of these explains the negative results.

Question

Quizplus · Accepted Answer

The promoter region, typically located at the 5' end of a gene, is essential for the initiation of transcription by RNA polymerase. Removing approximately 250 base pairs from the 5' end likely removed the promoter, preventing RNA polymerase from binding and initiating transcription, thus explaining the lack of mRNA production.

You Have Isolated a Piece of DNA That You Believe