Additionally, genes can have regulatory regions many kilobases upstream or downstream of the open reading frame. These act by binding to transcription factors which then cause the DNA to loop so that the regulatory sequence (and bound transcription factor) become close to the RNA polymerase binding site. For example, enhancers increase transcription by binding an activator protein which then helps to recruit the RNA polymerase to the promoter; conversely silencers bind repressor proteins and make the DNA less available for RNA polymerase. COUNT 5
QSN1 How do regulatory regions act? ANS1 by binding to transcription factors QSN2 What happens when a regulatory region binds to transcription factors? ANS2 the DNA to loop QSN3 How do enhancers increase transcription? ANS3 by binding an activator protein QSN4 What happens after an enhancer binds an activator protein? ANS4 helps to recruit the RNA polymerase to the promoter QSN5 What causes DNA to be less available for RNA polymerase? ANS5 silencers bind repressor proteins