Part:BBa_K1713000

Plac/ara-1, a hybrid promoter

The hybrid promoter ( Plac/ara-1 ) can be activated by the AraC protein in the presence of arabinose and repressed by the LacI protein in the absence of isopropyl b-D-1-thiogalactopyranoside (IPTG). The Plac/ara-1 is a hybrid promoter which is composed of the activation operator site from the araBAD promoter and repression operator sites from the lacZYA promoter. And the araBAD promoter is placed in its normal location relative to the transcription start site while the lacZYA promoter is placed both upstream and immediately downstream of the transcription start site. In the meanwhile, It can be activated by the AraC protein in the presence of arabinose and repressed by the LacI protein in the absence of isopropyl b-D-1-thiogalactopyranoside (IPTG). Attention: After sequencing, we found that this plasmids have two sites error on Suffix which is after the end of hybrid promoter sequence "cacaca" and the initial two bases of Suffix is changed from T-A to GAA. We can not make sure whether it will have an impact on function till now.

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 28
  
• 23
  COMPATIBLE WITH RFC[23]
• 25
  COMPATIBLE WITH RFC[25]
• 1000
  COMPATIBLE WITH RFC[1000]

Usage and Biology

Some related tests are specifically run on the hybrid promoter(Plac/ara-1). A mRFP is linked behind the promoter as a reporter and two different chemical inducers(Arabinose/IPTG) exist respectively for tests on the promoter. A series of different inducer's concentrations are set to test amples, and the expressions level of mRFP is linked with the influence that changed concentration of inducer had on the promoter. Related data after analysis show as the following charts.

Fig 1:The effect on the promoter of Arabinose. Fig 2:The effect on the promoter of IPTG.