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.

A significant increase in the fraction of FS m was observed in both MB2UCC and MB2CCC strains (Figure 9b) . Mutation of the À1 frame E-site sequence to UCC and CCC in the HIV-1 frameshift site may enhance incomplete translocation in Pathway I by allowing more interactions between E-site tRNA and the À1 frame. This result is consistent with the model that different mechanisms exist and participate in making frameshift proteins to different extents. The creation of a favorable condition for one pathway can affect the composition of frameshift proteins significantly. To date, no mutations affecting the composition of frameshift proteins have been reported in the literature. Notably, our experimental results show that in one case, FS% increases significantly without a change in the composition of frameshift products (Figure 9a) , while in another condition FS% increases a smaller amount but the composition of frameshift products change dramatically (Figure 9b) .