Difference between revisions of "Part:BBa K2012015"
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PcpcG2 promoter is a 238bp green-light activated promoter in Synechocystis PCC 6803(Part:BBa_K592003). The full length promoter is comprised of a G-box region, a CcaR-P activated promoter, and a constitutive promoter, which contributes to the leakiness under red light and low dynamic range. Therefore, we constructed PcpcG2-172, a 172bp truncated cpcG2 promoter deleted for the constitutive promoter.(For more detail, please  view our wiki: ["http://2016.igem.org/Team:HZAU-China/Experiments" ])
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PcpcG2 promoter is a 238bp green-light activated promoter in Synechocystis PCC 6803(Part:BBa_K592003). The full length promoter is comprised of a G-box region, a CcaR-P activated promoter, and a constitutive promoter, which contributes to the leakiness under red light and low dynamic range. Therefore, we constructed PcpcG2-172, a 172bp truncated cpcG2 promoter deleted for the constitutive promoter.(For more detail, please  view our wiki: "http://2016.igem.org/Team:HZAU-China/Experiments" )
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<html><img alt="00.1" src="https://static.igem.org/mediawiki/parts/7/71/T--HZAU--China--CcaS-CcaR.jpg" style="float:none;width:400px;height:240px"></html>
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<div style="text-align:left"><img alt="00.1" src="https://static.igem.org/mediawiki/parts/7/71/T--HZAU--China--CcaS-CcaR.jpg" style="float:none;width:400px;height:240px" ><br/>
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</span><strong>Figure 1. Mechanism of CcaS-CcaR system<span>.</span></strong><span><span>&nbsp;<br/>
 
</span><strong>Figure 1. Mechanism of CcaS-CcaR system<span>.</span></strong><span><span>&nbsp;<br/>
 
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<span>&nbsp;</span></span></span></span><span>CcaS is produced in a green-absorbing ground state, termed Pg. Absorption of green light flips CcaS to a kinase-active red-absorbing state (Pr) that phosphorylates the response regulator CcaR, which then binds to the G-box operator within cpcG2 promoter and activates transcription. Absorption of red light switches CcaS Pr back to Pg, which dephosphorylates P-CcaR, deactivating transcription.</span></div>
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<span>&nbsp;</span></span></span></span><span>CcaS is produced in a green-absorbing ground state, termed Pg. Absorption of green light flips CcaS to a kinase-active red-absorbing state (Pr) that phosphorylates the response regulator CcaR, which then binds to the G-box operator within cpcG2 promoter and activates transcription. Absorption of red light switches CcaS Pr back to Pg, which dephosphorylates P-CcaR, deactivating transcription.</span>
  
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<div style="text-align:left"><img alt="00.1" height="293" src="https://static.igem.org/mediawiki/parts/d/db/Hzau-china_cpcg2.jpg" style="float:none" width="480"></div>
 
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<p><span style="font-weight:bold">Figure 2. Mean fluorescence output in CcaS-CcaR system</span><strong>.</strong></p>
 
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Revision as of 11:02, 17 October 2016


PcpcG2-172, a modified PcpcG2 promoter

PcpcG2 promoter is a 238bp green-light activated promoter in Synechocystis PCC 6803(Part:BBa_K592003). The full length promoter is comprised of a G-box region, a CcaR-P activated promoter, and a constitutive promoter, which contributes to the leakiness under red light and low dynamic range. Therefore, we constructed PcpcG2-172, a 172bp truncated cpcG2 promoter deleted for the constitutive promoter.(For more detail, please view our wiki: "http://2016.igem.org/Team:HZAU-China/Experiments" ) <p/> 00.1  
Figure 1. Mechanism of CcaS-CcaR system. 

 
 CcaS is produced in a green-absorbing ground state, termed Pg. Absorption of green light flips CcaS to a kinase-active red-absorbing state (Pr) that phosphorylates the response regulator CcaR, which then binds to the G-box operator within cpcG2 promoter and activates transcription. Absorption of red light switches CcaS Pr back to Pg, which dephosphorylates P-CcaR, deactivating transcription.

 

Fluorescence assay of CcaS-CcaR system with PcpcG2-172 (BBa_K2012015) in CL1 (△EnvZ), and PCB (△CcaS) as chromophore.

Fluorescence under green light is 1.81-folds of red light, proving that green light activates output expression, the device works well. PcpcG2-172 shows high efficiency.

More importantly, leaked expression in darkness significantly reduced after truncation of the constitutive promoter.

 

Sequence and Features

Assembly Compatibility:
  • 10
    COMPATIBLE WITH RFC[10]
  • 12
    COMPATIBLE WITH RFC[12]
  • 21
    COMPATIBLE WITH RFC[21]
  • 23
    COMPATIBLE WITH RFC[23]
  • 25
    COMPATIBLE WITH RFC[25]
  • 1000
    COMPATIBLE WITH RFC[1000]