What does the lac repressor do?

1 Answer
Feb 20, 2018

Lac repressor /Lac I is the tetramer DNA binding protein and lactose(an inducer) allosterically bind with Lac I.

Explanation:

Wherever bacterial cell has very less amount or no lactose, lac mRNA is repressed because lac repressor /lac I bind with operator site and block the binding of RNA Polymerase so that lac mRNA will not be synthesized and lac operon will be turned off.In this way, cellular energy will not be wasted to synthesize the enzymes when cell does not need of them.This is called negative control.