Figure 2

Ten independent time courses of the abundance of protein monomers in the (positive) autoregulatory circuit. The availability of a cytosolic dimer state (red, using circuit topology DA1) significantly reduces the copy-number fluctuations of the monomer compared to the monomer-only (MO) circuit (blue). All corresponding MO and DA1 parameters have the same values. In the ensuing simulations initial conditions are chosen to be the steady state solution of the corresponding deterministic rate equation so that the transient behavior should be minimized.