Repressor: meaning, definitions and examples

genetics

A repressor is a DNA- or RNA-binding protein that inhibits the expression of one or more genes by binding to the operator or associated silencer region.

blocker, inhibitor, suppressor.

Which Synonym Should You Choose?

Word	Description / Examples
repressor	Often used in molecular biology to describe a protein that inhibits gene expression. The repressor binds to the operator region, preventing transcription
inhibitor	Frequently used in chemistry, biochemistry, and pharmacology to describe a substance that slows down or prevents a chemical reaction or other processes. ACE inhibitors are commonly used to treat high blood pressure and heart conditions
suppressor	Used in various fields to describe a factor or substance that restrains or reduces the activity of another element. In genetics, it refers to a gene that suppresses the effect of another gene. Tumor suppressor genes help prevent the uncontrolled growth of cells
blocker	Commonly used in everyday language and medicine to describe something that blocks or obstructs a process or pathway. The doctor prescribed a beta-blocker to manage her high blood pressure

Examples of usage

• The lac repressor binds to the operator in the absence of lactose.

• When the repressor is bound to the operator, RNA polymerase is blocked from transcribing the genes.

• The trp repressor prevents the transcription of the tryptophan biosynthesis genes.

• The binding of the repressor to the operator is sensitive to the concentration of the specific metabolite.

• In the presence of the inducer, the repressor undergoes a conformational change and releases the operator.