What is the protein product of the lac I gene of the lac operon?
1 Answer
Oct 2, 2016
The LacI gene codes for the repressor of the lac operon.
Explanation:
It can be somewhat confusing, but the LacI gene is not part of the Lac operon itself.
The Lac operon itself contains the genes for three enzymes:
- LacZ codes for
- LacY codes for
- LacA codes for
The LacI gene is a regulatory gene that codes for the lactose-inducible lac operon transcriptional repressor. In other words, it codes for the respressor of te Lac-operon.
LacI is always transcribed. When the repressor binds to the operator, the Lac genes can't be transcribed. For transcription to happen, the repressor first has to be inactivated.
