A mutation in E. coli results in a molecule known as a "super-repressor" because the operon is permanently repressed. Which of the following describes the most likely effect of the mutation on the repressor protein?
A) It cannot bind to the operator.
B) It cannot make a functional repressor.
C) It cannot bind to the inducer.
D) It makes a repressor that binds CAP.

Question

Quizplus · Accepted Answer

The mutation likely alters the repressor protein in a way that it cannot bind to the inducer. Normally, the inducer would bind to the repressor, causing it to change shape and release from the operator, allowing transcription. If the repressor cannot bind the inducer, it remains bound to the operator, continuously repressing the operon.

A Mutation in E