Part:BBa_K4621094

Fusion promoter composed of Pro755 and ProP

Usage, Biology and Characterization

Pro755 contains the promoter of rpsD（GQS52_23440）in SCUT-3. The promoter model predicted that the promoter expression intensity was about 75% of Pro1007（BBa_K3880007）. The fusion promoter composed of Pro755（BBa_K4621043）and ProP（BBa_K4621004）can control the gene expression switch while controlling its expression intensity.

Testing and validation

Pro755 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, Pro755 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
  COMPATIBLE WITH RFC[10]
• 12
  INCOMPATIBLE WITH RFC[12]

  Illegal NotI site found at 168
  
• 21
  COMPATIBLE WITH RFC[21]
• 23
  COMPATIBLE WITH RFC[23]
• 25
  COMPATIBLE WITH RFC[25]
• 1000
  COMPATIBLE WITH RFC[1000]