Activator

Definition

An activator is a protein that increases gene transcription by binding to an enhancer or promoter-proximal element. Activators facilitate the binding of RNA polymerase to the promoter, initiating transcription.

5 Must Know Facts For Your Next Test

1. Activators bind to specific DNA sequences known as enhancers or promoter-proximal elements.
2. They play a crucial role in positive regulation of gene expression.
3. The interaction between activators and RNA polymerase enhances the rate of transcription initiation.
4. Some activators require co-activators to function effectively.
5. Mutations in activator proteins can lead to dysregulation of gene expression and associated diseases.

Review Questions

• How do activators increase the rate of gene transcription?
• What are the specific DNA sequences called where activators bind?
• Why might some activators require co-activators?

Related terms

Repressor: A protein that inhibits gene transcription by binding to an operator or silencer region.

Operon: A cluster of genes under control of a single promoter and regulated together.

Enhancer: A DNA sequence that promotes transcription by serving as a binding site for activator proteins.