Biology:Ribosome Recycling Factor
| mitochondrial ribosome recycling factor | |
|---|---|
| Identifiers | |
| Symbol | MRRF |
| NCBI gene | 92399 |
| HGNC | 7234 |
| OMIM | 604602 |
| RefSeq | NM_138777 |
| UniProt | Q96E11 |
| Other data | |
| Locus | Chr. 9 q32-q34.1 |
Ribosome Recycling Factor (RRF) is a protein found in bacterial cells as well as eukaryotic organelles, specifically mitochondria and chloroplasts. It functions to recycle ribosomes after completion of protein synthesis.
Discovery
The ribosome recycling factor was discovered in the early 1970s by the work of Akira Kaji and Akikazu Hiroshima at the University of Pennsylvania.[1][2][3][4] Their work described the requirement for two protein factors to release ribosomes from mRNA. These two factors were identified as RRF, an unknown protein until then, and Elongation Factor G (EF-G), a protein already identified and known to function in protein synthesis. RRF was originally called Ribosome Releasing Factor but is now called Ribosome Recycling Factor.
Function
Recent evidence suggests RRF may accomplish the recycling of ribosomes by splitting ribosomes into subunits, thereby releasing the bound mRNA.[5]
Loss of RRF function
- In Bacteria (specifically Escherichia coli), loss of the gene encoding RRF is deleterious.[6] This makes RRF a possible target for new antibacterial drugs.
- Yeast mitochondrial RRF (mtRRF) is encoded by a gene in the cell nucleus. Loss of function of this gene leads to mitochondrial genome instability and respiratory incompetence.[7]
Structure and binding to ribosomes
The crystal structure of RRF was first determined by X-ray diffraction in 1999.[8] The most striking revelation was that RRF is a near-perfect structural mimic of tRNA, in both size and dimensions. One view of RRF can be seen here.
Despite the tRNA-mimicry, RRF binds to ribosomes quite differently from the way tRNA does.[9] It has been suggested that ribosomes bind proteins (or protein domain) of similar shape and size to tRNA, and this, rather than function, explains the observed structural mimicry.
See also
- Prokaryotic translation
- Ribosome
- Translation (genetics)
References
- ↑ "Factor dependent breakdown of polysomes". Biochem. Biophys. Res. Commun. 41 (4): 877–83. November 1970. doi:10.1016/0006-291X(70)90165-8. PMID 4920474. http://linkinghub.elsevier.com/retrieve/pii/0006-291X(70)90165-8.
- ↑ "Factor-dependent release of ribosomes from messenger RNA. Requirement for two heat-stable factors". J. Mol. Biol. 65 (1): 43–58. March 1972. doi:10.1016/0022-2836(72)90490-1. PMID 4553259. http://linkinghub.elsevier.com/retrieve/pii/0022-2836(72)90490-1.
- ↑ "Purification and properties of ribosome-releasing factor". Biochemistry 11 (22): 4037–44. October 1972. doi:10.1021/bi00772a005. PMID 4563926.
- ↑ "Role of elongation factor G and a protein factor on the release of ribosomes from messenger ribonucleic acid". J. Biol. Chem. 248 (21): 7580–7. November 1973. PMID 4583357. http://www.jbc.org/cgi/pmidlookup?view=long&pmid=4583357.
- ↑ "The ribosome-recycling step: Consensus or controversy?". Trends Biochem. Sci. 31 (3): 143–9. March 2006. doi:10.1016/j.tibs.2006.01.007. PMID 16487710. http://linkinghub.elsevier.com/retrieve/pii/S0968-0004(06)00033-8.
- ↑ "Ribosome recycling factor (ribosome releasing factor) is essential for bacterial growth". Proc. Natl. Acad. Sci. U.S.A. 91 (10): 4249–53. May 1994. doi:10.1073/pnas.91.10.4249. PMID 8183897. PMC 43762. http://www.pnas.org/cgi/pmidlookup?view=long&pmid=8183897.
- ↑ "Temperature-sensitive mutation in yeast mitochondrial ribosome recycling factor (RRF)". Nucleic Acids Res. 31 (14): 4218–26. July 2003. doi:10.1093/nar/gkg449. PMID 12853640. PMC 165964. http://nar.oxfordjournals.org/cgi/pmidlookup?view=long&pmid=12853640.
- ↑ "Crystal structure of Thermotoga maritima ribosome recycling factor: a tRNA mimic". Science 286 (5448): 2349–52. December 1999. doi:10.1126/science.286.5448.2349. PMID 10600747. http://www.sciencemag.org/cgi/pmidlookup?view=long&pmid=10600747.
- ↑ "Visualization of ribosome-recycling factor on the Escherichia coli 70S ribosome: functional implications". Proc. Natl. Acad. Sci. U.S.A. 101 (24): 8900–5. June 2004. doi:10.1073/pnas.0401904101. PMID 15178758. PMC 428444. http://www.pnas.org/cgi/pmidlookup?view=long&pmid=15178758.
External links
- ribosome+releasing+factor at the US National Library of Medicine Medical Subject Headings (MeSH)
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