The diagram below shows a DNA duplex. The template stran...

Question

The diagram below shows a DNA duplex. The template strand is identified, as is the location of the nucleotide.

Assume this region contains a gene transcribed in a bacterium. Identify the location of promoter consensus sequences and of the transcription termination sequence. <>

Accepted Answer

Hi, everyone. Let's take a look at this practice problem together which of the following defines a prokaryotes, intrinsic termination signal. The answer options are a, a short R N A sequence found in the untranslated region of M R N A and prokaryotes. B A long sequence of adenine nucleotides that is added to the three prime end of a messenger R N A option C A G C rich sequence followed by a series of mini uracil residues in the nascent R N A and option D A poly A that is added to the three prime end of the R N A transcript. So right off the bat, there's two answers that we can immediately eliminate. Do you know which ones they are? So the two answers we can eliminate are options B and D. And this is because both reference A poly A tell and recall. That is a long string of A's that is at the end of the three prime R N A products. Now, while procaryotes may have poly A tails on some R N A molecules, it is not on every single molecule and it is not involved in the termination signal. So that is why we are eliminating, eliminating options B and D immediately. Now, intrinsic termination is one of two ways that procaryotes terminate transcription. It is done through DNA having certain repeated sequences. So for termination, there must be a repeated G C sequence and then a poly a sequence on the DNA. So I have a drawing of a DNA sequence that I am putting up on the screen. It shows that repeated G C sequence and a poly A tail at the three prime end. Now, during transcription, the M R N A is made and I am putting up a drawing of that M R N A now and it would have the complimentary C G sequence and then a poly U sequence. Now what happens is due to complementary base pairing between the cytosine and guanine in these repeated sequences is a hairpin structure. And I am putting on the screen now a picture that demonstrates that hairpin structure. You can see that the guanine and cytosine are pairing and this makes it so that R N A polymerase is no longer able to continue transcription. Thus, the correct answer is option C A G C rich sequence followed by a series of mini uracil residues in the nascent R N A. OK. Everyone I hope you found this helpful and I'll see you soon for the next practice problem.

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The diagram below shows a DNA duplex. The template strand is identified, as is the location of the nucleotide.

Assume this region contains a gene transcribed in a bacterium. Identify the location of promoter consensus sequences and of the transcription termination sequence. <>

My Courses

Chemistry

Biology

Math

Physics

Business

Social Sciences

Programming

Product & Marketing

The diagram below shows a DNA duplex. The template strand is identified, as is the location of the nucleotide.Assume this region contains a gene transcribed in a bacterium. Identify the location of promoter consensus sequences and of the transcription termination sequence. <>

The diagram below shows a DNA duplex. The template strand is identified, as is the location of the nucleotide.

Assume this region contains a gene transcribed in a bacterium. Identify the location of promoter consensus sequences and of the transcription termination sequence. <>