Difference between revisions of "Part:BBa K1642010"

 
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Based on PcpcG2 and halorhodopsin, we established a biodesalination system which relies on red and green light. The light colors in the three stages are red light, green light and white light respectively.
 
 
In the growth stage, red light is enough for photosynthesis of cyanobacteria, which has been proved to be feasible by a recent report(Abe, K. et al. 2014). To further confirm it, we determined the growth curve under red light. This growth rate is no slower than that of the stain under natural light as long as we adjust the light intensity.
 
 
In the induction stage, the green light induces the expression of HR. Additionally, green light can’t provide energy source for chlorophyll, thus creating a starvation condition. And the starvation can inhibit active export of sodium, which is essential for biodesalination in the working stage.
 
 
In the working stage, halorhodopsin absorbs light to drive chloride import. Addtionally, cyanobacteria will regain energy under natural light. The biodesalination process controlled by PcpcG2 is shown in Figure 2.
 
<center>{{ Template:SJTU-BioX-Shanghai/Figure
 
| figure = [[File:SJTUB biode(2).png| 410px | frameless ]]
 
| float = middle
 
| id = 1.4.2
 
| label = Biodesalination process controlled by PcpcG2.
 
| descr = In the growth stage, cyanobacteria absorb energy from red light and grow to a certain density; In the induction stage, green-light induces the expression of halorhodopsin, and additionally pushes cyano bacteria to starvation status; In the working stage, engineered cyanobacteria absorb sodium chloride under natural light and cyanobacteria regain energy.
 
}}</center>
 
 
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===Usage and Biology===
 
===Usage and Biology===

Latest revision as of 22:09, 18 September 2015

Expression of Halorhodopsin under the control of PcpcG2

PcpcG2-HR is a plasmid used to test whether the protein halorhodopsin works as we expect.

Up and Down are sequences used for homologous recombination.

PcpcG2 is the promoter of cpcG2. CcaS phosphorylates CcaR under green light, and phosphorylated CcaR binds to promoter of cpcG2 to induce expression of cpcG2.

RBS is the RNA binding site, which will hopefully increase the expression level of HR.

Halorhodopsin (HR) proteins are light-driven inward-directed chloride pumps from halobacteria. We use this as our biodesalination driver which confers cyanobacteria the ability to absorb chloride to a significant degree.

Terminator is the transcription terminator for the E.coli RNA polymerase.

PcpcB is a constitutive promoter in cyanobacteria, and Kana is gene sequence for kanamycin resistance, so that bacteria which are successfully transformed this plasmid can be screened on the plate.


Sequence and Features


Assembly Compatibility:
  • 10
    COMPATIBLE WITH RFC[10]
  • 12
    COMPATIBLE WITH RFC[12]
  • 21
    INCOMPATIBLE WITH RFC[21]
    Illegal BamHI site found at 3398
  • 23
    COMPATIBLE WITH RFC[23]
  • 25
    INCOMPATIBLE WITH RFC[25]
    Illegal NgoMIV site found at 481
    Illegal NgoMIV site found at 966
    Illegal NgoMIV site found at 1125
    Illegal NgoMIV site found at 1446
    Illegal AgeI site found at 1317
  • 1000
    COMPATIBLE WITH RFC[1000]