Ribosome Recycling Factor

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mitochondrial ribosome recycling factor
Identifiers
Symbol MRRF
Entrez 92399
HUGO 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[edit]

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[edit]

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[edit]

Structure of RRF and Binding to Ribosomes[edit]

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[edit]

References[edit]

  1. ^ Hirashima A, Kaji A (November 1970). "Factor dependent breakdown of polysomes". Biochem. Biophys. Res. Commun. 41 (4): 877–83. PMID 4920474. doi:10.1016/0006-291X(70)90165-8. 
  2. ^ Hirashima A, Kaji A (March 1972). "Factor-dependent release of ribosomes from messenger RNA. Requirement for two heat-stable factors". J. Mol. Biol. 65 (1): 43–58. PMID 4553259. doi:10.1016/0022-2836(72)90490-1. 
  3. ^ Hirashima A, Kaji A (October 1972). "Purification and properties of ribosome-releasing factor". Biochemistry. 11 (22): 4037–44. PMID 4563926. doi:10.1021/bi00772a005. 
  4. ^ Hirashima A, Kaji A (November 1973). "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. PMID 4583357. 
  5. ^ Hirokawa G, Demeshkina N, Iwakura N, Kaji H, Kaji A (March 2006). "The ribosome-recycling step: Consensus or controversy?". Trends Biochem. Sci. 31 (3): 143–9. PMID 16487710. doi:10.1016/j.tibs.2006.01.007. 
  6. ^ Janosi L, Shimizu I, Kaji A (May 1994). "Ribosome recycling factor (ribosome releasing factor) is essential for bacterial growth". Proc. Natl. Acad. Sci. U.S.A. 91 (10): 4249–53. PMC 43762Freely accessible. PMID 8183897. doi:10.1073/pnas.91.10.4249. 
  7. ^ Teyssier E, Hirokawa G, Tretiakova A, Jameson B, Kaji A, Kaji H (July 2003). "Temperature-sensitive mutation in yeast mitochondrial ribosome recycling factor (RRF)". Nucleic Acids Res. 31 (14): 4218–26. PMC 165964Freely accessible. PMID 12853640. doi:10.1093/nar/gkg449. 
  8. ^ Selmer M, Al-Karadaghi S, Hirokawa G, Kaji A, Liljas A (December 1999). "Crystal structure of Thermotoga maritima ribosome recycling factor: a tRNA mimic". Science. 286 (5448): 2349–52. PMID 10600747. doi:10.1126/science.286.5448.2349. 
  9. ^ Agrawal RK, Sharma MR, Kiel MC, et al. (June 2004). "Visualization of ribosome-recycling factor on the Escherichia coli 70S ribosome: functional implications". Proc. Natl. Acad. Sci. U.S.A. 101 (24): 8900–5. PMC 428444Freely accessible. PMID 15178758. doi:10.1073/pnas.0401904101. 

External links[edit]