Written by the Fiveable Content Team • Last updated September 2025
Verified for the 2026 exam
Verified for the 2026 exam•Written by the Fiveable Content Team • Last updated September 2025
Definition
Repressors are proteins that suppress the transcription of a gene. They bind to specific DNA sequences, preventing RNA polymerase from initiating transcription and thus inhibiting gene expression.
Related terms
Operator: A segment of DNA to which a repressor binds. It's like the specific spot where our traffic cop stands.
Inducible Operon: A set of genes transcribed under control of an operator gene; however, transcription happens only in presence of some substances. This is like having a special event that allows cars to pass even when the light is red.
Lac Repressor: A DNA-binding protein which inhibits the expression of genes coding for proteins involved in lactose metabolism in bacteria. It's like a specialized traffic cop who only stops trucks carrying milk products.