Discussion

Our ribosome footprinting analysis reveals that Rpl10 loop mutant ribosomes exhibit clear defects in translation. A substantial proportion of footprints from these ribosomes accumulate at the start codon and the second amino acid, with markedly fewer reads across the coding sequence (CDS), suggesting impaired or slowed translation elongation. Frame-specific analysis further reveals a disruption in the translational reading frame, and the presence of distinct ribosome footprint lengths at the 5′ UTR points to perturbations in ribosome rotational dynamics.

These observations are consistent with previous work from the Dinman lab, which proposed that the P-site loop of Rpl10 plays a critical role in regulating ribosome rotation during translation. Our findings provide direct functional evidence supporting this model. Furthermore, cryo-EM data from our lab corroborate this by showing that the absence of the Rpl10 loop results in mispositioning of the P-site tRNA (Figure 10). Together, these results demonstrate that the Rpl10 loop is essential for proper tRNA placement and the coordination of ribosomal movements required for efficient translation.