Figure 2

Increase of pre-crRNA processing rate. The first and the second row in the panel correspond, respectively, to the number of pre-crRNA and crRNA molecules. The first, the second, and the third column correspond, respectively, to A), B) and C). The deterministic simulation corresponds to the magenta dashed line, while ten simulated stochastic trajectories correspond to the full blue curves. The parameter values are as experimentally measured, or as inferred from the measurements by the analysis: ${\lambda }_u=1{min}^{-1}$, ${\lambda }_p=1/100{min}^{-1}$, $k=1/100{min}^{-1}$, $\varphi =10{min}^{-1}$, $\left[u\right]=\left[p\right]=10$. The system is induced so that ϕ remains constant, while pre-crRNA processing rate (k): A) remains the same as the uninduced value, B) increases for three orders of magnitude (as in CasE overexpression experiments in [11]), C) increases for an additional order of magnitude relative to B). The figure shows that CasE overexpression can lead to a large generation of crRNA, but that increase of CasE above some value does not lead to an additional increase of crRNA amount (the saturation of crRNA).