Part:BBa_K3278002

pDawn with modified tac promoter

pDawn is a blue light control system which can start the expression of target gene under the inducement of blue light. More information in BBa_K1075044 added by iGEM13_Bonn.

However, expression leakage and delay are the two main problems of pdawn system. Leakage refers to the expression of target protein without light. According to our measurement, samples strictly kept away from light still had significant expression of GFP after being cultured for one night. Therefore, we carefully studied the gene circuits of pdawn system [2] [3] and hypothesized that enhancing the strength of the promoter of YF1 may enhance the repression of protein expression in the dark, thus solving the leakage problem.

In this part, we use the modified tac promoter(abbreviated as mtac promoter) to substitute the lacIq promoter in front of YF1 and Fixk2, largely reducing the leakage while maintain reasonable expression under blue light.

pDawn with T7 promoter is abbreviated as T7c below. pDawn with tac promoter is abbreviated as tac below. pDawn with modified tac promoter is abbreviated as mtac below. pDawn with J23119 promoter is abbreviated as 119 below. pDawn with J23100 promoter is abbreviated as 100 below.

Fig1. pDawn-tac-0 hour

Fig2. pDawn-tac-6 hour

Fig3. pDawn-tac-12 hour

Fig4. Dark to light-12 hour

Fig5. pDawn-tac-24 hour

Fig6. Dark to light-24 hour

Fig7. pDawn-tac-30 hour

Fig8. Dark to light-30 hour

Fig9. pDawn-tac-36 hour

Fig10. Dark to light-36 hour

To see more changes on pDawn, go to the websites below.

pDawn-mEGFP: <a href="https://parts.igem.org/Part:BBa_K3278000"> BBa_3278000</a>

pDawn with T7 promoter: <a href="https://parts.igem.org/Part:BBa_K3278001"> BBa_3278001</a>

pDawn with mtac promoter: <a href="https://parts.igem.org/Part:BBa_K3278002"> BBa_3278002</a> (good)

pdawn with tac promoter: <a href="https://parts.igem.org/Part:BBa_K3278005"> BBa_3278005</a>

pDawn with YF2: <a href="https://parts.igem.org/Part:BBa_K3278006"> BBa_3278006</a> (good)

Sequence and Features

Assembly Compatibility:

• 10
  COMPATIBLE WITH RFC[10]
• 12
  COMPATIBLE WITH RFC[12]
• 21
  INCOMPATIBLE WITH RFC[21]

  Illegal BglII site found at 2159
  
• 23
  COMPATIBLE WITH RFC[23]
• 25
  INCOMPATIBLE WITH RFC[25]

  Illegal NgoMIV site found at 46
  Illegal NgoMIV site found at 178
  Illegal NgoMIV site found at 272
  Illegal NgoMIV site found at 565
  Illegal NgoMIV site found at 1059
  Illegal NgoMIV site found at 1077
  Illegal NgoMIV site found at 1167
  Illegal AgeI site found at 397
  Illegal AgeI site found at 1525
  
• 1000
  INCOMPATIBLE WITH RFC[1000]

  Illegal BsaI site found at 1620
  Illegal BsaI.rc site found at 508