Riboswitch

Definition

A riboswitch is a regulatory segment of mRNA that binds a small target molecule, resulting in a change in the mRNA's activity. It plays a crucial role in gene expression by directly sensing cellular metabolites.

5 Must Know Facts For Your Next Test

1. Riboswitches can regulate gene expression at the level of transcription, translation, or mRNA stability.
2. They typically consist of two parts: an aptamer domain that binds the metabolite and an expression platform that changes conformation upon binding.
3. Common metabolites bound by riboswitches include vitamins, amino acids, and nucleotides.
4. The discovery of riboswitches has provided insight into how cells can control gene expression without protein intermediates.
5. Riboswitches are primarily found in bacteria, but examples have also been identified in plants and fungi.

Related terms

Operon:

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

Transcription Factor: A protein that binds to specific DNA sequences to regulate transcription.

mRNA Stability: The lifespan of mRNA molecules in the cell, influencing how long they are available for translation.