The Highly Conserved Codon following the Slippery Sequence Supports -1 Frameshift Efficiency at the HIV-1 Frameshift Site

Mathew, Suneeth F.; Crowe-McAuliffe, Caillan; Graves, Ryan; Cardno, Tony S.; McKinney, Cushla; Poole, Elizabeth S.; Tate, Warren P.

For the mRNA to disengage from its two tRNAs there must be significant perturbations to the typical precise ribosomal conformations at each step of the elongation cycle. Despite this, in 90-95% of cases the decoding molecule tRNA Gly can successfully bind and decode the GGG intercodon, allowing the ribosome to escape frameshifting by overcoming resistance from the unwinding of the upper stem and continue to translate the mRNA in the original frame (Fig. 7D) . However, in those ribosomes that do not 'escape' when the intercodon is in the A site, the tension placed on the mRNA is instead relieved by disruption of the codon:anticodon interactions of the P (and possibly E site) tRNA(s) to result in a 'spring-like' movement of the tRNAs and re-pairing in the −1 frame [62] .