One Regulator (ar)
From 2006.igem.org
Contents |
"lambda" (Giorgia)
- Background:
This strategy is based on the pR and pRM promoters of lambda phage. The input PoPs regulates the production of CI, which will act as an activator of pRM and as a repressor of pR.
pR is a constitutive promoter, which is repressed by cooperative binding of two CI dimers onto the operator sequences OR1 (highest affinity) and OR2. On the other hand, pRM is activated by CI binding to OR1 and OR2.
After CI concentration reaches a threshold, binding to OR3 (lowest affinity) and inactivation of pRM occurs.
- Pros:
- Since the two promoters are regulated by the same protein-operator interactions, repression and activation should be symmetrical.
- pR, pRM and CI are available from the registry.
- Open questions:
- Should OR3 be removed from the pRM sequence? Or would the late-repression of pRM not jeopardise the achievement of our desired behaviour?
- Which sequence could be adequate to replace OR3 (spacing between -35 and -10 of pRM has to be maintained)? Would this replacement influence the binding affinity of CI to OR1?
- Basal activity of pRM?
AraC (Giorgia)
This option was dumped after further literature reading.
"Lunatic Activator" (Christophe)
The "Lunatic Activator" is an activator because it is required for the transcription of gene 1 and 3, but is lunatic because it can also acts as a roadblock on genes 2 and 4. Send me an email if you know such protein.
Zinc Finger YY1 (Hervé)
Secondary Metabolism (Christophe)
The idea here would be to use an existing regulator that both activates and represses genes required in the secondary metabolism (e.g. Amino-acid production). To minimize interference with E.Coli, it would be wise to try a system from a very different bacteria (e.g. B. Subtilis).
