text: Barley yellow dwarf virus 5' UTR is a non-coding RNA element containing structural elements required for translation of the genome of the plant disease pathogen Barley yellow dwarf virus.
  Unlike eukaryotic mRNA, this virus lacks a 5 cap and a poly(A) tail but still circularises its mRNA through base pairing between two stem loops, one located in the 5 untranslated region (UTR) and the other within the 3 UTR. The structure within the 3 UTR has been previously characterised as the 3 cap-independent translation element (3 TE element) and the 5 UTR of barley yellow dwarf virus has been predicted to contain 4 stem loop structures. Mutagenesis showed that stem loop 4 is essential for base pairing with 3TE and only 5 bases are needed to base pair for mRNA circularization to occur.