In this chapter, we focused on how eukaryotic genes are regulated at the transcriptional level. Along the way, we found many opportunities to consider the methods and reasoning by which much of this information was acquired. From the explanations given in the chapter, How do we know that eukaryotic transcription factors bind to DNA sequences at or near promoter regions?

Video transcript

Hi, everyone. Let's take a look at this practice problem together in humans. What is the precursor protein before the RN A polymerase can bind to the promoter region? So we're talking about transcription in this problem. And RN A polymerase usually binds the promoter region. Let's take a look at some DNA. So here's the double strand of DNA and typically you have a promoter area where the RN A prelimerase binds in the transcription area. So you would have this RN A polymerase come and bind to the promoter area. However, in order for the RN a polymerase to bind there, it would need a precursor protein to bind to it first. So our question is asking us, what is that precursor protein? So let's take a look at our options. We've got activators, enhancers, basal transcription factors or repressors. Well, if we take a look at enhancers, recall that they are CS regulatory elements, they are, are part of that and CS regulatory elements and thus an enhancer is a DNA sequence. It's not a protein. So B cannot be correct. Now, activators repressors and basal transcription factors are all transcription factors. So our options left are all proteins. However, what gives away the answer is the word basil. And so basil here means the forming of a foundation to form a foundation or a base. And so a basal transcription factor would be the foundation or the precursor protein before the RN A polymerase here could bind to the promoter region. So our answer is c basal transcription factors. All right, everyone. I hope you found this helpful and I'll see you soon for the next practice problem.