Two Regulators (a,r)

From 2006.igem.org

Basic (Giorgia)

We will keep this strategy as our "last shore", since it is quite banal. Basically, one activator and one repressor genes will be under control of the same promoter, thus the encoded proteins will be produced in parallel. The two regulators will then act separately on their respective promoters. The tricky part of this strategy would be to find two regulators that activate/repress their promoters with similar "strength".

Antisense (Giorgia)

• Background:

In antisense strategy, repression of protein production takes place at the translational level. An antisense gene has a sequence exactly "opposite" (reversed, complementary) to the sequence of the gene that should be repressed. Transcription of both the antisense gene and the sense gene occurs, so that sense mRNA and antisense mRNA are produced. The "antisense" mRNA molecule binds tightly to its mirror image, thus preventing translation.Activation is achieved by means of an activator/promoter set, e.g. the AraC/pBAD.

• Problems:
  • How efficient is repression of translation? In bacteria, ribosomes bind while the DNA is being transcribed into mRNA.
  • Coordination of repression and activation could be a problem, due to a delay in repression.