Molecular Biology/Genetics USMLE Step 1 Practice Question
A prokaryotic operon codes for 2 enzymes and 1 regulatory protein. The operon is expressed only in the presence of a particular sugar. Initial mapping of the operon has differentiated the nontranscribed sequences from the transcribed sequences. Deletion of 10 nucleotides from one of the nontranscribed sequences results in transcription of the operon in both the presence and absence of the sugar. Which of the following sequences was most likely affected?
Answer choices
- AOperatorCorrect answer
- BActivator binding site
- CActivator gene
- DRepressor gene
- EPromoter
- FSilencer
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