R2 RNA element

R2 RNA element
Predicted secondary structure and sequence conservation of R2_retro_el
Identifiers
Symbol R2_retro_el
Rfam RF00524
Other data
RNA type Cis-reg
Domain(s) Eukaryota
SO 0000233

The R2 RNA element is a non-long terminal repeat (non-LTR) retrotransposable element that inserts at a specific site in the 28S ribosomal RNA (rRNA) genes of most insect genomes.[1] In order to insert itself into the genome, retrotransposon encoded protein (R2) protein makes a specific nick in one of the DNA strands at the insertion site and uses the 3′ hydroxyl group exposed by this nick to prime the reverse transcription process termed target primed reverse transcription (TPRT), where the RNA genome is transcribed into DNA.[2]

Contents

3' UTR element

The R2 element 3' UTR RNA is a cis-acting element identified in R2 retrotransposons which is involved in priming the reverse transcription process (an essential part of retrotransposon insertion into the host genome).[3] An RNA fragment found in the R2 3' untranslated region (3'UTR), has been shown to interact with one copy of R2 protein during TPRT. This fragment has been shown to possess conserved secondary structure within Drosophila and silk moths, and also between the two groups.[3]

5' UTR ribozyme

The 5' UTR of R2 RNA is thought to be capable of acting as a ribozyme and performs self-splicing.[4] This ribozyme has been found to have high sequence similarity to the HDV ribozyme but they are not homologous; the two sequences are thought to have undergone convergent evolution.[4]

References

  1. ^ Luan DD, Korman MH, Jakubczak JL, Eickbush TH (1993). "Reverse transcription of R2Bm RNA is primed by a nick at the chromosomal target site: a mechanism for non-LTR retrotransposition". Cell 72 (4): 595–605. doi:10.1016/0092-8674(93)90078-5. PMID 7679954. 
  2. ^ Christensen, SM; Ye, J, Eickbush, TH (2006). "RNA from the 5′ end of the R2 retrotransposon controls R2 protein binding to and cleavage of its DNA target site". Proceedings of the National Academy of Sciences of the United States of America 103 (47): 17602–7. doi:10.1073/pnas.0605476103. PMC 1693793. PMID 17105809. http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=1693793. 
  3. ^ a b Ruschak AM, Mathews DH, Bibillo A et al. (2004). "Secondary structure models of the 3′ untranslated regions of diverse R2 RNAs". RNA 10 (6): 978–87. doi:10.1261/rna.5216204. PMC 1370589. PMID 15146081. http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=1370589. 
  4. ^ a b Eickbush, DG; Eickbush, TH (2010 Jul). "R2 Retrotransposons Encode a Self-Cleaving Ribozyme for Processing from an rRNA Cotranscript". Molecular and cellular biology 30 (13): 3142–50. doi:10.1128/MCB.00300-10. PMC 2897577. PMID 20421411. http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=2897577. 

External links