5.8S ribosomal RNA

In molecular biology, the 5.8S ribosomal RNA (5.8S rRNA) is a non-coding RNA component of the large subunit of the eukaryotic ribosome and so plays an important role in protein translation. It is transcribed by RNA polymerase I as part of the 45S precursor that also contains 18S and 28S rRNA. Its function is thought to be in ribosome translocation.^[1] It is also known to form covalent linkage to the p53 tumour suppressor protein.^[2] 5.8S rRNA can be used as a reference gene for miRNA detection.^[3] The 5.8S ribosomal RNA is used to better understand other rRNA processes and pathways in the cell.^[4]

5.8S ribosomal RNA
Predicted secondary structure and sequence conservation of 5.8S ribosomal RNA
Identifiers
Symbol	5_8S_rRNA
Rfam	RF00002
Other data
RNA type	Gene; rRNA
Domain(s)	Eukaryota; Archaea[citation needed]
GO	GO:0003735 GO:0005840
SO	SO:0000375
PDB structures	PDBe

The 5.8S rRNA is homologous to the 5' end of non-eukaryotic LSU rRNA. In eukaryotes, the insertion of ITS2 breaks LSU rRNA into 5.8S and 28S rRNAs.^[5] Some flies have their 5.8 rRNA further split into two pieces.^[6]

Structure

L567.5 rRNA structure is approximately 150 nucleotides in size and it consists of plenty of folded strands, some of which are presumed to be single stranded.^[7] This ribosomal RNA, along with the 28S and 5S rRNA as well as 46 ribosomal proteins, forms the ribosomal large subunit (LSU).^[7] The 5.8S rRNA is initially transcribed along with the 18S and 28S rRNA in the 45S preribosomal RNA, along with the ITS 1 and ITS 2 (Internal transcribed spacer) and a 5’ and 3’ ETS (External transcribed spacer).^[8] The 5.8S rRNA is located between the two ITS regions, with ITS1 separating it from the 18S rRNA in the 5' direction, and ITS2 separating it from the 28S rRNA in the 3' direction. The ITS and ETS are cleaved away during rRNA maturation. This is accomplished through a continuous cleavage pathway performed by both endonuclease and exonuclease enzymes, cutting the spacers at specific locations.^[8]

References

1. Abou Elela S, Nazar RN (May 1997). "Role of the 5.8S rRNA in ribosome translocation". Nucleic Acids Research. 25 (9): 1788–1794. doi:10.1093/nar/25.9.1788. PMC 146658. PMID 9108162.
2. Fontoura BM, Atienza CA, Sorokina EA, Morimoto T, Carroll RB (June 1997). "Cytoplasmic p53 polypeptide is associated with ribosomes". Molecular and Cellular Biology. 17 (6): 3146–3154. doi:10.1128/MCB.17.6.3146. PMC 232167. PMID 9154813.
3. Shi R, Chiang VL (October 2005). "Facile means for quantifying microRNA expression by real-time PCR". BioTechniques. 39 (4): 519–525. doi:10.2144/000112010. PMID 16235564.
4. Nazar RN (June 1984). "The ribosomal 5.8S RNA: eukaryotic adaptation or processing variant?". Canadian Journal of Biochemistry and Cell Biology. 62 (6): 311–320. doi:10.1139/o84-044. PMID 6380683.
5. Lafontaine, D. L. J.; Tollervey, D. (2001). "The function and synthesis of ribosomes". Nature Reviews Molecular Cell Biology. 2 (7): 514–520. doi:10.1038/35080045. hdl:1842/729. PMID 11433365. S2CID 2637106.
6. Shimada, T. (August 1992). "Distribution of split 5.8S ribosomal RNA in Diptera". Insect Molecular Biology. 1 (1): 45–48. doi:10.1111/j.1365-2583.1993.tb00076.x. PMID 1343775. S2CID 46570307.
7. Walker TA, Pace NR (June 1983). "5.8S ribosomal RNA". Cell. 33 (2): 320–322. doi:10.1016/0092-8674(83)90413-0. PMID 6861202.
8. Henras AK, Plisson-Chastang C, O'Donohue MF, Chakraborty A, Gleizes PE (27 Oct 2014). "An overview of pre-ribosomal RNA processing in eukaryotes". Wiley Interdisciplinary Reviews: RNA. 6 (2): 225–242. doi:10.1002/wrna.1269. PMC 4361047. PMID 25346433.

External links

• Page for 5.8S ribosomal RNA at Rfam
• Arabidopsis 5.8S rRNA sequence
• Rice 5.8S rRNA sequence