What would be the result if the U-rich sequence after the fourth stem loop in the trp operon was replaced by a UG-rich sequence?
A) Attenuation would occur if tryptophan was high
B) Attenuation would occur if tryptophan is low
C) Attenuation would not occur if tryptophan was high

Question

Quizplus · Accepted Answer

The U-rich sequence after the fourth stem loop in the trp operon is crucial for the formation of a transcription termination loop (attenuator) when tryptophan levels are high, allowing RNA polymerase to disassociate from the DNA. Replacing this sequence with a UG-rich sequence would likely disrupt this mechanism, preventing proper termination of transcription under high tryptophan conditions, hence attenuation would not occur if tryptophan was high.

What Would Be the Result If the U-Rich Sequence After