Question

How is the DNA-binding behavior of polymerase similar to that of the lac repressor?

Answer 1

Answer:

The lac repressor is a protein that inhibits the transcription of the lac operon. It does this by binding to the operator, which partially overlaps with the promoter. When bound, the lac repressor gets in RNA polymerase's way and keeps it from transcribing the operon. whareas, un avaibility of lactose in the cell, the lac repressor binds tightly to the operator, preventing transcription by RNA polymerase. Therefore, when lactose is present, the lac repressor loses its ability to bind DNA. It floats off the operator, clearing the way for RNA polymerase to transcribe the operon. So, from the above figure clear that the binding behaviour of Polymerase are simliar in fasion as Lac repressor in presence of lactose.