Part:BBa_K3386002

A promoter driving expression of the 2′-phosphotransferase Mph(A)

Biology

The pMphR drives expression of the 2′-phosphotransferase Mph(A), if there is no erythromycin present, it remains bound by MphR repressor protein [1]. pMphR can be used in a system with MphR repressor protein, which upon binding of erythromycin releases the promoter and thus activates expression of selected gene.

Characterization

In this system pMphR was driving the expression of egfp and MphR was driven by a constitutive promoter (Fig. 1). Escherichia coli TOP10 strain was transformed with this system and the cells were grown for 20 h in LB with various erythromycin concentrations. Additionally, cells transformed with a construct lacking mphr gene were also grown in order to see how much fluorescence can be produced in absence of the repressor. There seemed to be a correlation between the amount of erythromycin present and the promoter activation, which suggests pMphR is functional (Fig. 2).

Figure 1. Genetic circuit designed to assess the functionality of pMphR.

Figure 2. Optical density (OD) normalized fluorescence values in different erythromycin (ERY) concentrations (0, 0.1, 0.5, 1, 10, 50, 100 µg/ml). The graph includes data from three repeats.

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]