Repressor vs. Corepressor

Repressornoun

Anything that represses.

Repressornoun

(genetics) Any protein that binds to DNA and thus regulates the expression of genes by decreasing the rate of transcription.

Repressornoun

an agent that represses

Repressor

In molecular 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 silencers. A DNA-binding repressor blocks the attachment of RNA polymerase to the promoter, thus preventing transcription of the genes into messenger RNA. An RNA-binding repressor binds to the mRNA and prevents translation of the mRNA into protein.

Corepressornoun

(genetics) Any substance that reacts with a genetic repressor in order to activate it and decrease gene expression

Corepressor

In the field of molecular biology, a corepressor is a molecule that represses the expression of genes. In prokaryotes, corepressors are small molecules whereas in eukaryotes, corepressors are proteins.