If the operator region of the trp operon in Escherichia coli were moved to a different section of the chromosome, but was otherwise unchanged, the most likely result would be that
A) the presence of tryptophan in the cell would no longer repress expression of the trp operon.
B) the tryptophan-trp repressor complex would still bind to the operator region.
C) the trp repressor protein would always bind to the operator region.
D) the presence of tryptophan in the cell would no longer repress expression of the trp operon and the tryptophan-trp repressor complex would still bind to the operator region.
E) the tryptophan-trp repressor complex would still bind to the operator region and the trp repressor protein would always bind to the operator region.

Question

Quizplus · Accepted Answer

The operator region is the site where the repressor protein binds to prevent transcription of the operon. If the operator region were moved to a different section of the chromosome, the repressor protein would still be able to bind to it and prevent transcription. However, the presence of tryptophan in the cell would no longer repress expression of the trp operon because the repressor protein would not be able to bind to the operator region in the presence of tryptophan.

If the Operator Region of the Trp Operon in Escherichia