Difference between revisions of "Antiswitches"
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Antiswitches are made of an aptamer and two stems: the aptamer stem and the antisense stem. (insert picture of antiswitch) | Antiswitches are made of an aptamer and two stems: the aptamer stem and the antisense stem. (insert picture of antiswitch) | ||
| − | The aptamer is the sequence that binds the ligand and causes a conformational (shape) change of the antiswitch molecule. While Smolke and Bayer used the aptamer for the ligand theophylline, aptamers for many other molecules are now being generated using rational design. The large number of possible aptamers provides versatility in what will control gene expression. | + | The aptamer is the sequence that binds the ligand and causes a conformational (shape) change of the antiswitch molecule. Aptamers can be highly specific for their particular molecules. The theophylline aptamer used by Smolke and Bayer can distinguish between caffeine and theophylline, which differ by a single methyl. |
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| + | While Smolke and Bayer used the aptamer for the ligand theophylline, aptamers for many other molecules are now being generated using rational design. The large number of possible aptamers provides versatility in what will control gene expression. | ||
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| + | The antisense stem contains a sequence that matches a targeted RNA transcript and a second sequence that sequesters this complementary sequence to keep it from binding the transcript. When the antisense stem is not duplexed with itself, it prevents translation by binding to the complementary mRNA. | ||
Revision as of 01:34, 12 November 2007
Antiswitches, trans-RNA molecules that regulate translation of mRNA based on ligands, were first developed by Smolke and Bayer (2005) in Saccharomyces cerevisiae. Two types of antiswitches were engineered: on-switches and off-switches. On-switches turn on gene expression in the presence of the ligand while off-switches turn off gene expression in the presence of ligand.
Design
Antiswitches are made of an aptamer and two stems: the aptamer stem and the antisense stem. (insert picture of antiswitch)
The aptamer is the sequence that binds the ligand and causes a conformational (shape) change of the antiswitch molecule. Aptamers can be highly specific for their particular molecules. The theophylline aptamer used by Smolke and Bayer can distinguish between caffeine and theophylline, which differ by a single methyl.
While Smolke and Bayer used the aptamer for the ligand theophylline, aptamers for many other molecules are now being generated using rational design. The large number of possible aptamers provides versatility in what will control gene expression.
The antisense stem contains a sequence that matches a targeted RNA transcript and a second sequence that sequesters this complementary sequence to keep it from binding the transcript. When the antisense stem is not duplexed with itself, it prevents translation by binding to the complementary mRNA.
