Author
Home > Science > What is the Difference Between Repressor and Corepressor?

Guilherme Mazui

•3 minutes to read

What is the Difference Between Repressor and Corepressor?

🆚 Go to Comparative Table 🆚

The main difference between a repressor and a corepressor lies in their mode of action in regulating gene expression. Here are the key differences between the two:

  1. Direct DNA binding: Repressors are proteins that directly bind to the operator sequence of a gene, blocking the binding of RNA polymerase and preventing transcription. In contrast, corepressors do not directly bind to DNA but instead bind to repressors and activate them to block gene expression.
  2. Activation: Repressors are activated by corepressors, which are proteins that bind to the repressor protein and help regulate gene expression indirectly. Corepressors themselves are not activated by other molecules.
  3. Function: Repressors prevent RNA polymerase from attaching to the promoter of the gene, thus inhibiting gene expression. Corepressors, on the other hand, compete with coactivators to bind transcription factors, indirectly controlling gene expression.

In summary, repressors are proteins that directly bind to DNA and block gene expression, while corepressors are proteins that bind to repressors and activate them to block gene expression indirectly.

On this page
  • What is the Difference Between Repressor and Corepressor?
  • Comparative Table: Repressor vs Corepressor

    • Comparative Table: Repressor vs Corepressor

    Here is a table summarizing the differences between a repressor and a corepressor:

    Feature Repressor Corepressor
    Definition A protein that directly binds to the operator sequence of a gene and blocks the attachment of RNA polymerase, preventing gene expression. A protein that does not directly bind to DNA but binds to the repressor protein, activating it and helping to block gene expression.
    Function Inhibits gene expression by blocking the binding of RNA polymerase to the promoter of the gene. Helps in gene regulation by binding to the repressor protein and activating it, indirectly controlling gene expression.
    DNA Binding Binds directly to the operator sequence of the gene. Cannot directly bind to the operator DNA sequence, but binds to the repressor protein.
    RNA Polymerase Binding Prevents RNA polymerase from attaching to the promoter. Competed with coactivators to bind transcription factors.
    Activation Can be activated by corepressors. Are proteins themselves that bind to repressor proteins.

    In summary, a repressor directly binds to the operator sequence of a gene and blocks the attachment of RNA polymerase, while a corepressor binds to the repressor protein and helps to block gene expression indirectly.

    Read more:

    Guilherme Mazui

    Guilherme Mazui is graduated in journalism from the Federal University of Minas Gerais (UFMG) and a master's degree in Communication from the University of São Paulo (USP). In addition, he has experience in advertising writing and has worked as a content editor in several companies.