The many paths to frameshifting: kinetic modelling and analysis of the effects of different elongation steps on programmed –1 ribosomal frameshifting

Liao, Pei-Yu; Choi, Yong Seok; Dinman, Jonathan D.; Lee, Kelvin H.

One step tRNA movement (Rx. Assuming steady state, r t and r -t can be represented by r t1 , r -t1 , r t2 and r -t2 (Supplementary Data). Figure 10 shows how a change in the rate constants in Rx.2 can affect the overall rate constants in Rx.1. The result suggests that repositioning of the E-site tRNA to the À1 frame (represented by r t1 ) may have a larger impact than repositioning of the P-site tRNA (represented by r t2 ) on the slippage toward the À1 frame (represented by r t ). On the other hand, repositioning the P-site tRNA back to zero frame (represented by r -t2 ) may have larger impact than repositioning the E-site tRNA (represented by r -t1 ) on the slippage toward the zero frame (represented by r -t ). Similarly, the same observation also applies to the movement for P-and A-site tRNAs (k pas2 , and k -pas2 ) in the model.