Modeled dependencies of GFP synthesis on the length of the 5′ UTR for the helicase-driven (A, Eq. 1) and 1D diffusion (B, Eq. 2) mechanisms of 40S scanning. Amounts of synthesized GFP are inversely proportional to 5′ UTR scanning time and sum of all other steps of initiation, elongation, and termination, which do not depend on the 5′ UTR length. GFP synthesis is modeled for scenarios when the sum of all other steps of translation, which are independent of 5′ UTR length, are 10-fold faster (> black), equal to (= red), 10-fold slower (< blue), 100-fold slower (<< cyan), or 1000-fold slower (<<< magenta) than the scanning of the 50 nt-long 5′ UTR.
