Difference between revisions of "Part:BBa K1893015"

Latest revision as of 20:00, 28 October 2016

Arabinose inducible promoter (pBAD)

This composite part is composed of a pBAD arabinose inducible promoter system developed by the 2014 Imperial team (BBa_K1321333) and an upstream reverse terminator (BBa_B0025) to terminate transcription of an antisense encoded araC transcription factor in the pBAD system. This part enables arabinose inducible expression of a downstream coding sequence, and can be switched off by the addition of D-glucose.

Usage and Biology

When arabinose is absent, araC forms a homodimer and binds to operator sites upstream of the pBAD promoter. This generates an inhibitory DNA loop that blocks RNA polymerase binding and prevents transcription. In the presence of L-arabinose, the dimer dissociates from the DNA, allowing transcription of the coding sequence downstream of the pBAD promoter. The promoter can then be switched off via catabolite repression by adding D-glucose to the system.

We have characterised the activation range of this part using GFP as a reporter. The results of our these characterisation experiments can be found here (BBa_K1893017).

Sequence and Features

Assembly Compatibility:

10
COMPATIBLE WITH RFC[10]
12
INCOMPATIBLE WITH RFC[12]
Illegal NheI site found at 1342
21
INCOMPATIBLE WITH RFC[21]
Illegal BamHI site found at 1281
23
COMPATIBLE WITH RFC[23]
25
INCOMPATIBLE WITH RFC[25]
Illegal AgeI site found at 1116
1000
INCOMPATIBLE WITH RFC[1000]
Illegal SapI site found at 1098

@@ Line 3: / Line 3: @@
 <partinfo>BBa_K1893015 short</partinfo>
-A construct for controlling the expression of a gene in front of the pBAD promoter. We added the reverse terminator B0025 to the 2014 Imperial part for use in plasmids without a reverse terminator, such as pSB1A2.
+This composite part is composed of a pBAD arabinose inducible promoter system developed by the 2014 Imperial team [https://parts.igem.org/Part:BBa_K1321333 (BBa_K1321333)] and an upstream reverse terminator [https://parts.igem.org/Part:BBa_B0025 (BBa_B0025)] to terminate transcription of an antisense encoded araC transcription factor in the pBAD system. This part enables arabinose inducible expression of a downstream coding sequence, and can be switched off by the addition of  D-glucose.
 ===Usage and Biology===
-Without any arabinose in the system, araC forms a homodimer, binding to operator sites upstream of the pBAD promoter, generating an inhibitory loop in the DNA that prevents access by RNAP. In the absence of glucose, and the presence of L-arabinose, the dimer dissociates from the DNA, allowing transcription of whatever is downstream of the pBAD promoter. We have characterised the activation range of this part by using GFP as a reporter construct. You can find the information [https://parts.igem.org/Part:BBa_K1893017 here (BBa_K1893017)].
+When arabinose is absent, araC forms a homodimer and binds to operator sites upstream of the pBAD promoter. This generates an inhibitory DNA loop that blocks RNA polymerase binding and prevents transcription. In the presence of L-arabinose, the dimer dissociates from the DNA, allowing transcription of the coding sequence downstream of the pBAD promoter. The promoter can then be switched off via catabolite repression by adding D-glucose to the system.
+We have characterised the activation range of this part using GFP as a reporter. The results of our these characterisation experiments can be found here [https://parts.igem.org/Part:BBa_K1893017 (BBa_K1893017)].
-It is also possible to switch off the pBAD promoter via catabolite repression once the promoter has been induced by L-arabinose by adding D-glucose to the system.