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− | <div id="design" class="container"> | + | <div id="system" class="container"> |
− | <div id="design_header" class="container_header"> | + | <div id="system_header" class="container_header"> |
− | <h2><span>4. Scene & Design</span></h2> | + | <h2><span>3. Introduction of system forming the basis</span></h2> |
| </div><!-- /_header --> | | </div><!-- /_header --> |
− | <div id="design_contents" class="container_contents"> | + | <div id="system_contents" class="container_contents"> |
− | <p class="normal_text">Our project begins from the scene that the Magic Mirror answers the question of the Queen.<br> | + | <p class="normal_text"> Before introduction of our genetic circuit’s design, we will introduce a system that form the basis of our project.<br> |
− | We pick up 4 famous scenes and introduce them in order. <br><br> | + | They are TA system.<br> |
− | <a href="#sce1"> Scene1 : The Magic Mirror’s Answer</a><br> | + | <a href="#sys1"> What is TA system?</a><br> |
− | <a href="#sce2"> Scene2 : The Queen’s Trap</a><br> | + | <a href="#sys2"> The art of MazF / MazE</a><br> |
− | <a href="#sce3"> Scene3 : Snow White's Sleep</a><br>
| + | The expression of real beauty by MazE / MazF<br> |
− | <a href="#sce4"> Scene4 : The Prince’s Rescue</a><br>
| + | MazE / MazF expression of real beauty<br> |
− | </p><br><br>
| + | The creation of real beauty under magic MazE / MazF<br> |
− | <div id="sce1_header"> | + | The creation of real beauty enchanted by MazE / MazF<br> |
− | <h3><span>Scene1 : The Magic Mirror’s Answer</span></h3> | + | The creation of real beauty under the spell of MazE / MazF<br> |
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| + | </p><br><br> |
| + | <div id="sys1_header"> |
| + | <h3><span>3.1 What is TA system?</span></h3> |
| </div><!-- /_header --> | | </div><!-- /_header --> |
− | <div id="sce1"> | + | <div id="sys1"> |
− | <div id="sce1_contents"> | + | <div id="sys1_contents"> |
− | <div align="center"><img src="https://static.igem.org/mediawiki/2016/f/f5/T--Tokyo_Tech--koma1.png" height ="200"><br></div> | + | <div align="center"><p class="normal_text">Toxin-antitoxin system</p><br></div> |
− | <p class="normal_text"><span style="font-style : italic">“Magic mirror on the wall, who is the fairest one of all?”<br> | + | <p class="normal_text">A toxin-antitoxin system is composed of two or more cognate genes that encode toxins and antitoxins. Toxins are proteins, whereas antitoxins are either proteins or non-coding RNAs. [1] Many prokaryotes have toxin-antitoxin systems, and organisms often have them in multiple copies. [2][3] Changes in the physiological conditions, such as stress conditions or viral infection leads to the antitoxin degradation, and proteases degrade many antitoxins. Unleashed toxin proteins impede or alter cellular processes including translation, cell division, DNA replication, ATP synthesis, mRNA stability or cell wall synthesis and lead to dormancy. This dormant state probably enables the bacteria to survive in unfavorable conditions. |
− | The mirror answered,<br>
| + | In general, toxin is more stable than antitoxin, but antitoxin is expressed to a higher level.<br><br> |
− | “Snow White is the fairest one.” </span><br><br>
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− | The magic Mirror <span style="font-style: italic">coli</span> can produce RhlI protein under low temperature. Rhl protein production leads to production of the signaling molecule, C4HSL which tells the Queen that Snow White is the fairest, and the Queen <span style="font-style: italic">coli</span> receives this molecule.
| + | <div align="center"><p class="normal_text">一つ目のtoxin-anti-toxin : MazF / MazE</p><br></div> |
| + | <p class="normal_text">MazF is a toxin protein, and MazE is its cognate antitoxin protein. MazF is a ribosome-independent endoribonuclease. This endoribonuclease activity leads to bacterial growth arrest. MazE and MazF form homodimers, and MazF dimer cleaves mRNAs at ACA sites. [4] One MazE dimer binds to two MazF dimers, thereby inactivates endoribonuclease activity of MazF dimer. [5] MazE is labile, subjected to degradation by ClpAP protease, whereas MazF is more stable. [6]<br><br> |
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| </p> | | </p> |
− | </div>
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− | </div>
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− | <div id="sce2_header">
| + | <div align="center"><p class="normal_text">二つ目のtoxin-anti-toxin : YafO / YafN</p><br></div> |
− | <h3><span>Scene2 : The Queen’s Trap</span></h3>
| + | <p class="normal_text">YafO is a toxin protein, and YafN is its cognate antitoxin protein. [7] YafO is a ribosome-associated mRNA interferase that cleaves mRNAs’ downstream 11-13 bases of the translation initiation sites. When 70S ribosome is dissociated, YafO associates with 50S ribosome subunit and gets endoribonuclease activity. YafO and YafN forms a complex Via binding with YafN, YafO is neutralized. [8] YafN is labile, subjected to degradation by Lon protease, whereas YafO is more stable [9].<br><br> |
− | </div><!-- /_header -->
| + | |
− | <div id="sce2">
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− | <div id="sce2_contents">
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− | <div align="center"><img src="https://static.igem.org/mediawiki/2016/8/8e/T--Tokyo_Tech--koma2.png" height ="200"><br></div>
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− | <p class="normal_text"><span style="font-style : italic">The Queen prepared a poisoned apple.<br>
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− | She decided to transform into a Witch and give the apple to Snow White.</span><br><br>
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− | The Queen, which has received C4HSL, produces LasI and MazF.<br>
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− | LasI produces signaling molecule, 3OC12HSL which represents the Poisoned Apple.<br>
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− | Additionally, produced MazF stops the translation in the Queen <span style="font-style : italic">coli</span>. MazE is incorporated into the genetic circuit so that MazE expression does not stop translation immediately. If the translation stops the moment MazF is expressed, sufficient amount of LasI will not be produced, and neither will 3OC12HSL. Then the Queen will fail the assassination of Snow White.
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| </p> | | </p> |
− | </div>
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− | </div>
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− | <div id="sce3_header">
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− | <h3><span>Scene3 : Snow White's Sleep</span></h3>
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− | </div><!-- /_header -->
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− | <div id="sce3">
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− | <div id="sce3_contents">
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− | <div align="center"><img src="https://static.igem.org/mediawiki/2016/6/6f/T--Tokyo_Tech--koma3.png" height ="200"><br></div>
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− | <p class="normal_text"><span style="font-style : italic">Snow White, who always takes people at their word, bit the apple, then sank into unconsciousness soon.</span><br><br>
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− | The basic design of Snow White <span style="font-style : italic">coli</span>’s genetic circuit is almost the same as the Queen <span style="font-style : italic">coli’</span> s.<br>
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− | Snow White <span style="font-style : italic">coli</span>, which has received the C12HSL: the Poisoned Apple, expresses RhlI and MazF.<br>
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− | Produced RhlI produces a signaling molecule: C4HSL. As was described in the introduction of the Queen in the previous section , it can receive C4HSL and monitor Snow White <span style="font-style: italic">coli</span> through this.<br>
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− | In addition, expressed MazF stops the translation in the Snow White <span style="font-style : italic">coli</span>.
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− | </p>
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| </div> | | </div> |
| </div> | | </div> |
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− | <div id="sce4_header"> | + | <div id="sys2_header"> |
− | <h3><span>Scene4 : The Prince’s Rescue</span></h3> | + | <h3><span>The art of MazF / MazE </span></h3> |
| </div><!-- /_header --> | | </div><!-- /_header --> |
− | <div id="sce4"> | + | <div id="sys2"> |
− | <div id="sce4_contents"> | + | <div id="sys2_contents"> |
− | <div align="center"><img src="https://static.igem.org/mediawiki/2016/4/40/T--Tokyo_Tech--koma4.png" height ="200"><br></div>
| + | <p class="normal_text">In our project, mazF and mazE are incorporated as a toxin and an antitoxin, respectively. Functioning of these two proteins makes it possible to evaluate the beauty of Snow White with GFP and RFP. <br> |
− | <p class="normal_text"><span style="font-style : italic">Although he knew her death, he couldn’t help lifting her up because of her beauty.<br> | + | We will give you an example for a better understanding. Imagine that RFP is expressed little by little in E. coli.<br> |
− | Then, she opened her eyes!
| + | When MazF expression is induced, the mRNA of GFP is cut, and GFP cannot be translated. Additionally, when MazE is induced, MazE and MazF forms a complex. MazF loses its function, which restarts GFP translation.<br><br> |
− | </span><br><br>
| + | In this way, we can control protein translation. That’s why we decided to represent Snow White story.<br><br> |
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− | The Prince <span style="font-style: italic">coli</span> has received 3OC12HSL expresses AmiE. In general, it is said that AmiE degrades HSL with C8 or more. This leads to degradation of the Poisoned Apple that is 3OC12HSL.<br>
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− | When the poison apple is degraded, MazF expression stops in Snow White, and gradually its function is canceled by MazE. Then, translation restarts in Snow White <span style="font-style: italic">coli</span>.
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| </p> | | </p> |
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− | </div><!-- /design_contents --> | + | </div><!-- /system_contents --> |
− | </div><!-- /design --> | + | </div><!-- /system --> |
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| <div id="function" class="container"> | | <div id="function" class="container"> |