Part:BBa_K3989008

Engineered quorum sensing esaR promoter: PesaR-C

A promoter that can interact with EsaR protein and inhibit downstream gene transcription.

Basic information

This part represents a promoter(P_esa) variant with two esa box, which can be bound to EsaR protein(see figure 2). esa box is a 18bps period located at a specific position of the promoter. After binding to the box, the EsaR will repress the recruitment of the RNA polymerase and inhibit the downstream transcription. However, when there are AHL molecules(such as 3OC6HSL) existing in the environment, they will interact with the EsaR and release it from the promoter, thus the transcription can be started.(Figure 1) The transcription level is controlled by the concentration of the AHL molecules.

Figure 1. Mechanism of the EsaR being an repressor under the control of the original P_esaR. The red dots are the specific AHL molecule and in our project it is 3OC6HSL[1]

Below is the figure of the structure of the original promoter and the engineered one.

Figure 2. The structure of P_esaR-C and the original P_esaR.[2]

As we can see in figure 2, the original promoter: P_esaR has only one esa box located at position -10 and the P_esaR-C has an additional esa box which locates between position -10 and -35. Previous studies has shown that even with a same amount of AHL molecules and same type of the EsaR regulator, the gene expression level can still be different depending on the type of the promoter.(see figure 3)

//Figure 3.Gene expression controlled by AHL molecules, EsaR regulator and P_esaR promoter. On the left side, the test is based on the P_esaR promoter and on the right side, the test is based on the P_esaRC promoter. If one use 10nM 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 281
  Illegal XhoI site found at 1
  
• 23
  COMPATIBLE WITH RFC[23]
• 25
  COMPATIBLE WITH RFC[25]
• 1000
  COMPATIBLE WITH RFC[1000]