FIGURE 9.

The current (Eq. 1) as a function of U₀ when the ribosome “on” rate k can be modified by direct interactions with elongation factor and PAB proteins. The Gaussian chain approximation is used with persistence length ℓ = a. A–C show hypothetical, qualitative trajectories in the presence of a changing phase diagram. As U₀ is increased, R decreases. With 4πaDC_∞/p = 0.6 fixed, the phase boundaries shown in A–C correspond to R/a = 25,3,3/2, respectively. In addition, if k₀ > k₁, the effective binding rate k_effC_∞/p also decreases with increasing U₀, resulting in the trajectories indicated by the dot. (D) Currents for k₀C_∞/p = 50, k₁C_∞/p = 0.3, and N = 100. The weak maximum appears only for small 4πaDC_∞/p.