Part:BBa_K4621090

Fusion promoter composed of Pro251 and ProP

Usage, Biology and Characterization

Pro251 contains the promoter of GQS52 _ 10395 in SCUT-3. The promoter model predicted that the promoter expression intensity was about 25 % of Pro1007（BBa_K3880007）. The fusion promoter composed of Pro251（BBa_K4621039） and ProP （BBa_K4621004）can control the gene expression switch while controlling its expression intensity.

Testing and validation

Pro251 was inserted into the chitin-inducible promoter ProP to form a fusion promoter. The regulation of gene expression can be achieved by placing it before the coding of the target gene. In our study, Pro251 stably expressed the target gene under the premise of chitin induction to control the production of ectoine and hydroxyectoine. We verified its regulation effect by LB fermentation.

For the experimenting group, we added chitin at 24 h to induce expression, and extended the total fermentation time to 5 days, to test the general accumulation.

We are surprising by the effect when combining the ProP with p24880 (p1007 & p1008), however, the results are seemingly incompatible with other data that higher expression leads to decrease on production. This phenomenon may be explained by the hypothesis of severe overexpressing leading to rapid reduction on growth and survival of SCUT-3, that p24880 carrier yield a large amount of ectoine and hydroxyectoine once induced by chitin, leading to immediate reduction in the general metabolism due to loss of living bacteria. If this case is true, p24880 is still not sufficient for long-period fermentation, and should be optimized sorely.

Sequence and Features

Assembly Compatibility:

• 10
  INCOMPATIBLE WITH RFC[10]

  Illegal EcoRI site found at 352
  
• 12
  INCOMPATIBLE WITH RFC[12]

  Illegal EcoRI site found at 352
  
• 21
  INCOMPATIBLE WITH RFC[21]

  Illegal EcoRI site found at 352
  Illegal BamHI site found at 454
  
• 23
  INCOMPATIBLE WITH RFC[23]

  Illegal EcoRI site found at 352
  
• 25
  INCOMPATIBLE WITH RFC[25]

  Illegal EcoRI site found at 352
  Illegal NgoMIV site found at 42
  Illegal NgoMIV site found at 468
  
• 1000
  COMPATIBLE WITH RFC[1000]