FIGURE 5.

The effective diffusional distance or harmonic distance over which recycled ribosomes must diffuse. (A) The dependence of R/a as a function of loop binding energy U₀ is shown for N = 100 persistence lengths of coding mRNA. For large binding energies U₀, the initiation and termination sites are brought closer together. The crossover between the end-to-end distribution function of a free chain to that of a loop occurs near Increasing the length of the short noncoding ends of the mRNA predominantly increases the typical distance R in the large U₀, looped regime. (B) The N-dependence of R/a with the ratio of noncoding persistence lengths to coding persistence lengths (m + n)/N = 1/2. The N-dependence manifests itself primarily in the low U₀, open chain regime. (C) The N dependence of R/a for various U₀.