What does the lac repressor protein bind to when the lac operon is turned off what does the lac repressor protein bind to when the lac operon is turned on?
The other region is the OPERATOR (O) e coli cells contains several copies of a DNA binding proteins known as the lac repressor, which can be bind to the O region
your answer: Operator
When the lac repressor binds to the O region, RNA polymerase is prevented from beginning the process of transcription. In effect, the binding of the repressor protein turns the operon "off" by...