5' UTR

Definition

The 5' Untranslated Region (5' UTR) is a segment of mRNA located upstream of the start codon. It plays a crucial role in the regulation of translation efficiency and stability of the mRNA.

5 Must Know Facts For Your Next Test

1. 1. The 5' UTR contains regulatory elements that can influence ribosome binding and translation initiation.
2. 2. It does not code for proteins but can contain upstream open reading frames (uORFs) that regulate downstream translation.
3. 3. Secondary structures within the 5' UTR, such as hairpins, can affect mRNA stability and translation efficiency.
4. 4. The length and sequence composition of the 5' UTR can vary significantly between different genes and organisms.
5. 5. Mutations in the 5' UTR can lead to diseases by disrupting normal gene expression regulation.

Review Questions

• 1. What is the primary function of the 5' UTR in mRNA?
• 2. How can secondary structures within the 5' UTR affect gene expression?
• 3. Why might mutations in the 5' UTR lead to diseases?

Related terms

mRNA:

Messenger RNA, which carries genetic information from DNA to ribosomes for protein synthesis

Translation Initiation: The process by which ribosomes assemble on an mRNA molecule to begin protein synthesis

Upstream Open Reading Frame (uORF): A sequence within the 5' UTR that can regulate downstream gene expression