Five prime untranslated region

The five prime untranslated region (5' UTR) is a particular section of messenger RNA (mRNA).

A mRNA codes for a protein through translation. The mRNA also contains regions that are not translated: in eukaryotes, the 5' untranslated region, 3' untranslated region, cap and polyA tail.

In prokaryotic mRNA the 5' UTR is normally short. Some viruses and cellular genes have unusual long structured 5'UTRs which may have roles in gene expression.

mRNA structure, approximately to scale for a human mRNA, where the median length of the 5'UTR is 170 nucleotides

Several regulatory sequences may be found in the 5' UTR:

• Binding sites for proteins, that may effect the mRNAs stability or translation, for example iron responsive elements, which occur in the 5' UTRs (and 3' UTRs) of a small number of eukaryotic mRNAs that regulate gene expression in response to iron.
• Sequences that promote the initiation of translation.

References

[1] The implications of structured 5' untranslated regions on translation and disease. Semin Cell Dev Biol 2005, 16:39-47

External links

[2] UTResource