Five prime untranslated region
The 5′ untranslated region is the region of a messenger RNA (mRNA) that is directly upstream from the initiation codon. This region is important for the regulation of translation of a transcript by differing mechanisms in viruses, prokaryotes and eukaryotes. While called untranslated, the 5′ UTR or a portion of it is sometimes translated into a protein product. This product can then regulate the translation of the main coding sequence of the mRNA. In many organisms, however, the 5′ UTR is completely untranslated, instead forming a complex secondary structure to regulate translation.
The binding of an IRP (iron regulatory protein) to and IRE (iron response element), which are hairpin loops, regulate translation.
In molecular biology, messenger ribonucleic acid (mRNA) is a single-stranded molecule of RNA that corresponds to the genetic sequence of a gene, and is read by a ribosome in the process of synthesizing a protein.
Universal structure of eukaryotic mRNA, showing the structure of the 5' and 3' UTRs.
mRNA circularisation and regulation
Overview of mRNA decay pathways in the different life domains.