Theory 49/Synthetic Biology
Leak Is a Promoter Ratio
The claim
The leak of a genetic circuit is set by the ratio of promoter strength to repressor affinity rather than by promoter strength, so a strong promoter can be tight with a strong repressor.
01The mechanism
Leak is the expression that survives repression; it depends on how completely the repressor occupies the site relative to how hard the promoter drives.
02Predictions
- P1Leak should track the ratio.
- P2Promoter strength alone should mispredict.
03Refutation
Leak tracking promoter strength would remove the affinity term.