- Polysome
Polyribosomes (or polysomes) are a cluster of ribosomes, bound to a
mRNA molecule, first discovered and characterized by Jonathan Warner, Paul Knopf, and Alex Rich in 1963.cite journal |author=Warner JR, Knopf PM, Rich A |title=A multiple ribosomal structure in protein synthesis |journal=Proc. Natl. Acad. Sci. U.S.A. |volume=49 |issue= |pages=122–9 |year=1963 |url=http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pubmed&pubmedid=13998950 |pmid=13998950 |doi=10.1073/pnas.49.1.122 [http://www.garfield.library.upenn.edu/classics1977/A1977DV63600002.pdf Summary] ] Polyribosomes read one strand of mRNA simultaneously, helping to synthesize the same protein at different spots on the mRNA, mRNA being the "messenger" in the process of protein synthesis. They may appear as clusters, linear arrays, or rosettes in routine: this is aided by the fact that mRNA is able to be twisted into a circular formation, creating a cycle of rapid ribosome recycling, and utilization of ribosomes. 5' 7-methylguanosine cap and 3'polyA tail aids in this process.cite book |author=Harvey Lodish et al. |title=Molecular cell biology |publisher=Scientific American Books |location=New York |year=1999 |isbn=0-7167-3136-3 |chapter=4.5. Stepwise Formation of Proteins on Ribosomes |chapterurl=http://www.ncbi.nlm.nih.gov/books/bv.fcgi?rid=mcb.section.901#914]Polyribosomes can be found in three forms: free, cytoskeletal bound and membrane bound.
External links
* [http://www.ncbi.nlm.nih.gov/books/bv.fcgi?rid=mboc4.figgrp.1090 Theoretical and experimental structure of polysome]
References
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