Treatment of the RNA polymerase/DNA complex with DNase in vitro is a DNA footprinting technique.Which of the following is the technique used for?
A)to identify the termination sequence for transcription
B)to locate the start site for transcription
C)to locate the promoter site
D)to identify the position of enhancer sequences

Question

Quizplus · Accepted Answer

DNA footprinting is used to locate the promoter site in this context. By treating the RNA polymerase/DNA complex with DNase, the enzyme will only cut the unprotected regions of DNA which are not bound to the RNA polymerase. This leaves a "footprint" of the DNA protected by the polymerase, which can be visualized by gel electrophoresis. By comparing the DNase-treated DNA to untreated DNA, the location of the RNA polymerase can be determined and therefore the location of the promoter site can be inferred.

Treatment of the RNA Polymerase/DNA Complex with DNase in Vitro