Mutations Affecting lac Operon Expression

Mutations Affecting lac Operon Expression - lacO + ) to...

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Mutations Affecting lac Operon Expression Wild Type lacI + lacO + lacZ + Inducible Enzymes produced only when lactose present; no lactose = no enzymes lacI + lacO + lacZ + Inducible Diploid lacI + lacO + lacZ + Mutation in the Repressor ( lacI ) Gene lacI - lacO + lacZ + Constitutive Enzymes produced at all times Mutant repressor ( lacI - ) can’t bind to operator ( lacO + ) lacI - lacO + lacZ + Inducible Wild Type repressor ( lacI + ) binds to both lacI + lacO + lacZ + operators ( lacO + ) to prevent transcription lacI S lacO + lacZ + Never Induced Enzymes never produced Mutant repressor ( lacI S ) can’t bind lactose, so always able to bind operator ( lacO + ) lacI S lacO + lacZ + Never Induced Mutant repressor ( lacI S ) binds to both lacI + lacO + lacZ + operators (
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Unformatted text preview: lacO + ) to prevent transcription, even with lactose trans-dominant Mutation in the Operator ( lacO ) Gene lacI + lacO C lacZ + Constitutive Operator ( lacO C ) sequence changed so wild type repressor ( lacI + ) cannot bind lacI + lacO C lacZ + Constitutive Wild type repressors ( lacI + ) cannot bind to lacI + lacO + lacZ + mutant operator sequence ( lacO C ) lacI + lacO C lacZ-Inducible Mutant operator sequence ( lacO C ) next to lacI + lacO + lacZ + mutant lacZ-= no enzymes and cannot prevent repressor binding at other operator ( lacO + ) cis-dominant...
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