Positive regulators

Definition

Positive regulators are proteins that enhance the transcription of specific genes by binding to DNA and facilitating RNA polymerase action. They play a crucial role in upregulating gene expression in prokaryotic cells.

5 Must Know Facts For Your Next Test

1. Positive regulators often bind to promoter or enhancer regions on DNA, increasing the likelihood that RNA polymerase will transcribe the associated gene.
2. They are essential for the precise regulation of metabolic pathways, allowing cells to adapt quickly to environmental changes.
3. Examples of positive regulators include activators like CAP (catabolite activator protein) in bacteria, which helps initiate transcription in the presence of cAMP.
4. The activity of positive regulators can be influenced by small molecules or other environmental signals, which either activate or inhibit their function.
5. Mutations affecting positive regulators can lead to dysregulated gene expression, impacting cell function and survival.

Review Questions

Related terms

Promoter:

A region of DNA where RNA polymerase binds to start transcription.

Activator: A protein that increases gene transcription by binding to an enhancer or promoter-proximal element.

cAMP:

A secondary messenger important for intracellular signal transduction, often involved in activating certain regulatory proteins like CAP.