The ribosome is the molecular machine responsible for translating an mRNA message into its corresponding protein. It accomplishes this goal with the help of two molecules: tRNA and release factor protein. tRNA, which adapts the mRNA anticodon to the growing polypeptide chain, is selected into the ribosome with remarkable speed and accuracy. The method the ribosome employs during tRNA selection involves acceleration of the irreversible forward rate constants in the pathway: GTPase activation and accommodation. We have developed an in vitro selection scheme for mutants of tRNA^Trp that are able to accelerate these forward rate constants on a near-cognate UGA codon. Structural studies of our mutant tRNA collection reveal a common structural rearrangement that is shared by these molecules. The rearrangement centers on the D-stem region of the molecule. This region is known to adopt an alternate structure during the A/T state, when the tRNA anticodon is sampling the decoding center and the CCA end remains bound to EF-Tu. The tip of helix 69, a conserved region of the 23S rRNA, appears to form stabilizing interactions during this state. To test whether our miscoding mutants are exploiting this stabilizing interaction in order to more readily sample the cognate All' state, we mutated residue 1913 of this helix. This mutation was completely able to abolish the miscoding phenotype of our mutant tRNAs yet had no effect on their ability to decode the cognate UGG codon. These results suggest that helix 69 plays a role in stabilizing tRNA as they adopt the All' state during tRNA selection on the ribosome.