Constitutive mutation in operator gene If a constitutive mutation happens in the operator of an inducible operon, does that mean that repressors won't be able to bind them ? Or does it mean that even if repressors are bound, they will not have any effect on the gene ? I am specifically talking about lac operon.

For the lac operon there are two possibilities for constitutive expression mutations:

1. The operator is never closed.



Reason: Mutation of the repressor, so its not present, doesn't bind or binds only with very low affinity for the operon.

1. The repressor can not bind.



Reason: The binding site for the repressor is mutated.

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