Difference between revisions of "Part:BBa K902065"

Revision as of 19:43, 28 October 2012

Rhamnose inducible, glucose repressible promoter (pRha)

The P_rha promoter is two promoters in one. In its native E. coli, the 5' end of the promoter serves to express the rhaR and rhaS control genes. The 3' end of the promoter expresses the RhaBAD rhamnose metabolic genes.

In rhamnose, the following occurs: RhaR transcription factor is activated by rhamnose to upregulate rhaR and rhaS. RhaS in turn up-regulates the rhaBAD operon. These functions are dependent on the binding of the catabolite receptor protein (CRP) cAMP complex to the promoter. Additionally, function of RhaS is improved in the presence of rhamnose (Egan & Schleif, 1993). Note that this activation necessarily depends on CRP-cAMP (cAMP receptor protein) complex being bound to the promoter

The glucose response: The promoter is subject to repression via global catabolite repression. With glucose present, cAMP levels are low and CRP is unable to bind to the promoter. RhaS is unable to activate transcription of the rhaBAD side of the promoter and it is thus repressed by glucose.

The iGEM Calgary 2012 used the rhaBAD side of the promoter to control expression of our kill system. We selected this promoter since it is repressed by glucose and activated by rhamnose. We designed our system to constituitively express rhaS so that it is not dependent on rhamnose to be activated. Please see the design details on our [http://2012.igem.org/Team:Calgary/Project/HumanPractices/Killswitch/Regulation#rhamnose Wiki]. Also, we tested the promoter sans modified expression of rhaR and rhaS with GFP and S7 micrococcal nuclease.

Sequence and Features

Assembly Compatibility:

10
COMPATIBLE WITH RFC[10]
12
COMPATIBLE WITH RFC[12]
21
COMPATIBLE WITH RFC[21]
23
COMPATIBLE WITH RFC[23]
25
COMPATIBLE WITH RFC[25]
1000
COMPATIBLE WITH RFC[1000]

@@ Line 2: / Line 2: @@
 <partinfo>BBa_K902065 short</partinfo>
-The pRha promoter is two promoters in one. In its native E. coli, the 5' end of the promoter serves to express the rhaR and rhaS control genes. The 3' end of the promoter expresses the rhaBAD rhamnose metabolism genes.
+The P<sub>rha</sub> promoter is two promoters in one. In its native <i>E. coli</i>, the 5' end of the promoter serves to express the <i>rhaR</i> and <i>rhaS</i> control genes. The 3' end of the promoter expresses the RhaBAD rhamnose metabolic genes.
-The rhamnose response: [https://parts.igem.org/wiki/index.php?title=Part:BBa_K902069 RhaR] transcription factor is activated by rhamnose to upregulate [https://parts.igem.org/wiki/index.php?title=Part:BBa_K902069 rhaR] and [https://parts.igem.org/wiki/index.php?title=Part:BBa_K902068 rhaS]. [https://parts.igem.org/wiki/index.php?title=Part:BBa_K902068 RhaS] in turn up-regulates the rhaBAD operon. These functions are dependent on the binding of the catabolite receptor protein (CRP) cAMP complex to the promoter. Additionally, function of RhaS is improved in the presence of rhamnose (Egan & Schleif, 1993).
-The glucose response: The promoter is subject to repression via global catabolite repression.
+In rhamnose, the following occurs: [https://parts.igem.org/wiki/index.php?title=Part:BBa_K902069 RhaR] transcription factor is activated by rhamnose to upregulate [https://parts.igem.org/wiki/index.php?title=Part:BBa_K902069 <i>rhaR</i>] and [https://parts.igem.org/wiki/index.php?title=Part:BBa_K902068 <i>rhaS</i>]. [https://parts.igem.org/wiki/index.php?title=Part:BBa_K902068 RhaS] in turn up-regulates the rhaBAD operon. These functions are dependent on the binding of the catabolite receptor protein (CRP) cAMP complex to the promoter. Additionally, function of RhaS is improved in the presence of rhamnose (Egan & Schleif, 1993). Note that this activation necessarily depends on CRP-cAMP (cAMP receptor protein) complex being bound to the promoter
-Please see the details on our [http://2012.igem.org/Team:Calgary/Project/HumanPractices/Killswitch/Regulation#rhamnose Wiki].
+The glucose response: The promoter is subject to repression via global catabolite repression. With glucose present, cAMP levels are low and CRP is unable to bind to the promoter. RhaS is unable to activate transcription of the <i>rhaBAD</i> side of the promoter and it is thus repressed by glucose.
+The iGEM Calgary 2012 used the <i>rhaBAD</i> side of the promoter to control expression of our kill system. We selected this promoter since it is repressed by glucose and activated by rhamnose. We designed our system to constituitively express <i>rhaS</i> so that it is not dependent on rhamnose to be activated. Please see the design details on our [http://2012.igem.org/Team:Calgary/Project/HumanPractices/Killswitch/Regulation#rhamnose Wiki]. Also, we tested the promoter sans modified expression of <i>rhaR</i> and <i>rhaS</i> with [https://parts.igem.org/Part:BBa_K902066 GFP] and [https://parts.igem.org/Part:BBa_K902084 S7 micrococcal nuclease].