The

Barley yellow dwarf virus Barley yellow dwarf (BYD) is a plant disease caused by the ''barley yellow dwarf virus'' (BYDV), and is the most widely distributed viral disease of cereals. It affects the economically important crop species barley, oats, wheat, maize, tritical ...

-like cap-independent translation element (BTE) is an RNA element found in the

3' UTR In molecular genetics, the three prime untranslated region (3′-UTR) is the section of messenger RNA (mRNA) that immediately follows the translation termination codon. The 3′-UTR often contains regulatory regions that post-transcriptionally ...

of some

luteovirus ''Luteovirus'' is a genus of viruses, in the family ''Tombusviridae''. There are 13 species in this genus. Plants serve as natural hosts. The geographical distribution of Luteoviruses is widespread, with the virus primarily infecting plants via ...

es. This element mediates

translation Translation is the communication of the Meaning (linguistic), meaning of a #Source and target languages, source-language text by means of an Dynamic and formal equivalence, equivalent #Source and target languages, target-language text. The ...

of genomic RNA and subgenomic RNA1 (sgRNA1). BTEs have a consensus sequence, GGAUCCUGGGAAACAGG, embedded in series of three to six stem-loops that radiate from a central hub. BTE has been found to bind to

eIF4G Eukaryotic translation initiation factor 4 G (eIF4G) is a protein involved in eukaryotic translation initiation and is a component of the eIF4F cap-binding complex. Orthologs of eIF4G have been studied in multiple species, including humans, yeast ...

and weakly to

eIF4E Eukaryotic translation initiation factor 4E, also known as eIF4E, is a protein that in humans is encoded by the ''EIF4E'' gene. Structure and function Most eukaryotic cellular mRNAs are blocked at their 5'-ends with the 7-methyl-guanosine fi ...

(proteins involved in translation initiation). BTE allows translation initiation of an

mRNA 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 Protein biosynthesis, synthesizing a protein. mRNA is ...

without a 7mG cap (required for

in most

eukaryotic Eukaryotes () are organisms whose cells have a nucleus. All animals, plants, fungi, and many unicellular organisms, are Eukaryotes. They belong to the group of organisms Eukaryota or Eukarya, which is one of the three domains of life. Bacte ...

mRNA). Other forms of

cap-independent translation element In molecular biology, a cap-independent translation element (CITE or 3'CITE) is an RNA sequence found in the 3'UTR of many RNA plant viruses. Eukaryotic mRNAs contain a 5' cap structure which is required for efficient binding of translation ini ...

s (CITE) exist (primarily in plant viruses from the Luteovirus, Necrovirus, Dianthovirus and Umbravirus genera of plant

viruses A virus is a submicroscopic infectious agent that replicates only inside the living cells of an organism. Viruses infect all life forms, from animals and plants to microorganisms, including bacteria and archaea. Since Dmitri Ivanovsky's 1 ...

, but also in some host mRNA; notably many

heat shock The heat shock response (HSR) is a cell stress response that increases the number of molecular chaperones to combat the negative effects on proteins caused by stressors such as increased temperatures, oxidative stress, and heavy metals. In a normal ...

mRNA lack a 7mG cap but are still translated). The general purpose of BTE and these other CITE's is to get the

ribosome Ribosomes ( ) are macromolecular machines, found within all cells, that perform biological protein synthesis (mRNA translation). Ribosomes link amino acids together in the order specified by the codons of messenger RNA (mRNA) molecules to ...

to begin translation without the 7mG cap. In the case of BTE it "tricks"

eIF4F Eukaryotic initiation factor 4F (eIF4F) is a heterotrimeric protein complex that binds the 5' cap of messenger RNAs (mRNAs) to promote eukaryotic translation initiation. The eIF4F complex is composed of three non-identical subunits: the DEAD- ...

(eIF4E, eIF4G are parts of eIF4F) into "telling" the ribosome that a 7mG cap is present.

References

External links

* Cis-regulatory RNA elements {{molecular-cell-biology-stub