The bacterial insertion sequence IS10 uses antisense ...

Question

The bacterial insertion sequence IS10 uses antisense RNA to regulate translation of the mRNA that produces the enzyme transposase, which is required for insertion sequence transposition. Transcription of the antisense RNA gene is controlled by P_OUT, which is more than 10 times more efficient at transcription than the P_IN promoter, which controls transposase gene transcription.
If a mutation of P_IN eliminates its ability to function in transcription, what is the likely effect on the transposition of IS10?

If a mutation of P_IN eliminates its ability to function in transcription, what is the likely effect on the transposition of IS10?

Accepted Answer

Hey, everyone. Let's take a look at this question together. A strain of bacteria is grown in a medium rich in vitamin B nine and vitamin B 12. This leads to the methylation of a DNA sequence near the gene coding for the transposes enzyme. This enzyme is essential for transposition to take place in bacteria. How will this methylation affect its function? Is it answer choice. A inhibition of transcription of the transposes gene. Is it answer choice B increased frequency of transposition. Answer choice C increased frequency of translation of transposes gene or answer choice D the number of transposes enzymes will remain unchanged. Let's work this problem out together to try to figure out which of the following answer choices describes how methylation will affect the function of the gene. So first, let's recall what methylation is to try to figure out what the effect would be. And we note that methylation is that addition of a methyl group to the DNA sequence and the effect of methylation on the DNA DNA sequence can affect the binding of the transcription factors. Since methylation is the addition of a methyl group to the DNA sequence in its promoter regions or other regulatory elements. And in this case, it is near the gene that is coding for that transposes enzyme. So since those transcription factors cannot bind because of the methylation, that means that the transcription of that transposes gene will not occur. And as a result of the transcription of that transposes gene not occurring, it leads to decreased production of the transposes enzyme as well as decreased transposition frequency. And so looking at our answer choices, we can see that answer choice B says increased frequency of transposition which we know it will lead to a decrease in the frequency of transposition. And answer choice C says increased frequency of translation of transposes gene which we know that it will lead to a decreased frequency of transcription of that transposes gene. And then answer choice D says that the number of transposes enzymes will remain unchanged. However, we know that the number of transposes enzymes will decrease. So answer choice BC and D are all incorrect and answer choice. A inhibition of transcription of the transposes gene is the correct answer. Since we know that methylation will affect the function of the transpose gene by preventing those transcription factors from binding, leading to the transcription of the transposes gene not occurring. And as a result of transcription not occurring, it leads to that decreased production of the transposes enzyme as well as decreased transposition frequency. So answer choice A is the only correct answer. I hope you found this video to be helpful. Thank you and goodbye.

Key Concepts

Transposase Function

Antisense RNA Regulation

Promoter Function and Efficiency

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