Question

Transcriptional activators promote elongation in what three ways?

a) RNA splicing, histone acetylation, enhancer looping
b) RNA processing, RNA cleavage, ribosome assembly
c) RNA modification, translation initiation, termination
d) RNA elongation, promoter clearance, enhancer looping

Answer 1

Transcriptional activators promote RNA elongation, facilitate promoter clearance, and contribute to enhancer looping, all of which are integral components of the transcription elongation process.

Step-by-step explanation:

Transcriptional activators promote elongation in RNA elongation, promoter clearance, and enhancer looping. During the initiation phase, RNA polymerase binds to the promoter, signaling DNA unwinding. Enhancers, binding sequences for transcription factors, facilitate the interaction between activators and the transcription initiation complex, including RNA polymerase. This interaction is vital for stabilizing the bent DNA structure that allows RNA polymerase II to begin the transcription process.

Binding of a transcription factor to an enhancer can lead to the initiation of the recruitment of RNA polymerase, and enhancers can also affect the efficiency of transcription but are not essential for the process to occur. Once RNA polymerase is bound to the DNA, elongation begins with the addition of nucleotides forming the mRNA strand. Ultimately, transcription is terminated as RNA polymerase transcribes a terminator sequence and detaches from the DNA.