Part:BBa_K592003

PcpcG2 promoter, ccaR-regulated

PcpcG2 is the green-light activated promoter from the genome of Synechocystis PCC6803. This 238 bp sequence is used by Jeffrey Tabor in pJT122 plasmid and contains the entire region upstream of cpcG2 and downstream of ccaR (Tabor et al. 2011). PcpcG2 is regulated by the light-activation of ccaS/ccaR. The gene downstream to this promoter is transcribed upon activation by ccaS/ccaR, via green light.

References:

Hirose Y, Shimada T, Narikawa R, Katayama M, Ikeuchi M (2008) Cyanobacteriochrome CcaS is the green light receptor that induces the expression of phycobilisome linker protein. Proc Natl Acad Sci U S A 105: 9528-9533.

Tabor, J. J., Levskaya, A., and Voigt, C. A. (2011). Multichromatic control of gene expression in Escherichia coli. J. Mol. Biol. 405, 2, 315–324.

Experience

 

Promoter cpcG2 is a 238bp green-light activated promoter from the genome of Synechocystis PCC6803. We tested the efficiency of the promoter by measuring the fluorescence of output sfGFP when bacteria are illuminated with green, red or no light. (For more detail, please view our wiki: http://2016.igem.org/Team:HZAU-China/Experiments)

 

Fig.1 Mean sfGFP fluorescence of CcaS-CcaR system under green light, red light and darkness.

 

As is shown in the figure, in E.coli strain JT2, PcpcG2 produces 266.0 ± 19.3 and 509.0 ± 55.4 au of sfGFP in red and green light, corresponding to 1.91 ± 0.34-fold activation, demonstrating that PcpcG2 is functionally regulated by light, green-activated and red-repressed.

 

However, the figure also shows that that leaked expression is severe in dark surroundings. To better respond to red and green light, we optimized the promoter by refactoring it and created an innovative promoter, PcpcG2-172, with the truncation of a constitutive promoter within the cpcG2 promoter (BBa_K2012015. For more detail, please view our wiki: http://2016.igem.org/Team:HZAU-China/Experiments).

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]