Part:BBa_K3527000

PhoA Promoter

PhoA 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]

Contribution

The phoA promoter is repressed by high phosphate concentrations. Under phosphate limited conditions, phoA promoter (basic parts BBa_K3527000) is activated. There are the other two phoA promoter sequence (basic parts: (BBa_K1139200 and BBa_K737023) which are much shorter than that of BBa_K3527000, as indicated by the following figure 1.

Figure 1

Engineering Success

Regulation of phoA promoter by phosphate concentration The function of phoA promoter was evaluated by the regulation of transcription of the gene of enhanced green fluorescent protein (EGFP). Using this reporting system, we showed that compared with the control, the bacteria containing PhoA-EGFP showed a significant fluorescence intensity difference (Figure 1) in the absence of phosphate in the medium. When the phosphate concentration added into the culture, the fluorescence intensity decreased to a level similar to the control culture.

Figure 2

Different concentrations of phosphate were added to the culture medium for treatment, within 15 minutes, compared with the control group, the E. coli containing PhoA-GFP plasmid had a higher detectable fluorescence value in the 0-0.2mM concentration range.

According to the experiment results listed above, we consider that our phoA promoter fulfills our expected design.