A mutation in the lacI gene results in an active repressor protein that can no longer bind allolactose.Which would be true of the phenotype of the mutant strain?

Question

Quizplus · Accepted Answer

The lacI gene codes for the lac repressor, which inhibits the expression of the lac operon genes (including lacZ, which encodes β-galactosidase) in the absence of lactose. If a mutation in lacI results in a repressor that cannot bind allolactose (the inducer, a derivative of lactose), the repressor will not be inactivated by the presence of lactose. Therefore, the lac operon will remain repressed even when lactose is available, leading to repression of β-galactosidase expression in the presence of lactose.

A Mutation in the LacI Gene Results in an Active