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 POUT, which is more than 10 times more efficient at transcription than the PIN promoter, which controls transposase gene transcription. If a mutation of PIN eliminates its ability to function in transcription, what is the likely effect on the transposition of IS10?

Verified step by step guidance

1. Understand the role of transposase: Transposase is an enzyme required for the transposition of the insertion sequence IS10. It is produced from the mRNA transcribed by the PIN promoter.
2. Identify the effect of the PIN mutation: A mutation that eliminates the function of the PIN promoter will prevent the transcription of the transposase gene, leading to no production of transposase enzyme.
3. Consider the role of antisense RNA: Antisense RNA, transcribed from the POUT promoter, regulates the translation of transposase mRNA by binding to it and preventing its translation.
4. Analyze the impact on transposition: Without transposase, the insertion sequence IS10 cannot transpose, as the enzyme is essential for this process.
5. Conclude the effect: The mutation in the PIN promoter, by stopping transposase production, will likely result in the cessation of IS10 transposition.

Key Concepts

Transposase Function

Transposase is an enzyme that facilitates the movement of transposable elements, such as insertion sequences, within the genome. It recognizes specific DNA sequences at the ends of the transposable element and catalyzes the cut-and-paste mechanism, allowing the element to insert itself into new locations. The activity of transposase is crucial for the transposition process, making its regulation a key factor in the behavior of insertion sequences like IS10.

Antisense RNA Regulation

Antisense RNA is a strand of RNA that is complementary to a specific mRNA molecule, and it can bind to that mRNA to inhibit its translation. In the case of IS10, the antisense RNA regulates the translation of transposase by binding to its mRNA, thereby controlling the amount of transposase produced. This regulatory mechanism is essential for maintaining the balance of transposase levels and ensuring proper transposition activity.

Promoter Function and Efficiency

Promoters are DNA sequences that initiate transcription of a gene by providing a binding site for RNA polymerase. The efficiency of a promoter, such as POUT and PIN in the IS10 system, determines how effectively transcription occurs. If a mutation in the PIN promoter eliminates its function, the transcription of the transposase gene will cease, leading to a significant reduction in transposase production and, consequently, a likely decrease in the transposition activity of IS10.