The protein produced by Huntington’s disease (huntingtin) interferes with general transcription factor (called CBP) and prevents it from binding the promoter. CBP activates genes involved in cell survival.

i) Which step in gene expression is huntingtin preventing?

ii) In the presence of huntingtin, are the genes activated by CBP expressed? Explain.

iii) Could this effect be produced in a prokaryote, why?