- Silent mutation
Silent mutations are
DNA mutation s that do not result in a change to theamino acid sequence of aprotein . They may occur in a non-coding region (outside of agene or within anintron ), or they may occur within anexon in a manner that does not alter the finalamino acid sequence. The phrase silent mutation is often used interchangeably with the phrasesynonymous mutation ; however, synonymous mutations are a subcategory of the former, occurring only within exons.Because silent mutations do not alter protein function they are often treated as though they are evolutionarily neutral. However, many organisms are known to exhibit
codon usage bias es, suggesting that there is selection for the use of particular codons due to translational stability. Silent mutations may also affect splicing, or transcriptional control.In molecular cloning experiments, it can be useful to introduce silent mutations into a gene of interest in order to create or remove recognition sites for restriction enzymes. An online tool that can analyse a sequence of interest for possible mutations to create restriction sites is given in the External Links section.
Recent results suggest that silent mutations can have an effect on subsequent protein structure and activity [ [http://www.sciencemag.org/cgi/content/full/315/5811/466 | Komar (2006) SNPs, Silent But Not Invisible] ] , [ [http://sciencenow.sciencemag.org/cgi/content/full/2006/1222/2 | Beckman (2006)The Sound of a Silent Mutation] ] .
References
*
* " [http://jmg.bmjjournals.com/cgi/content/full/38/12/863 Full text] "
* " [http://www.sciencemag.org/cgi/content/abstract/sci;315/5811/525 Abstract] " " [http://www.sciencemag.org/cgi/content/full/sci;315/5811/466 Summary] " " [http://www.sciencemag.org/cgi/content/full/sci;315/5811/525 Full Text] "ee also
*Degeneracy of the genetic code
*Genealogical DNA test External links
* [http://watcut.uwaterloo.ca/watcut/watcut/template.php An online tool for silent mutagenesis]
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