Translational activators align mRNAs at the small mitoribosomal subunit for translation initiation.

ABSTRACT: Mitochondrial gene expression is essential for oxidative phosphorylation. Mitochondrial-encoded mRNAs are translated by dedicated mitochondrial ribosomes (mitoribosomes), whose regulation remains elusive. In Saccharomyces cerevisiae, nuclear-encoded mitochondrial translational activators (TAs) facilitate transcript-specific translation by a yet unknown mechanism. Here, we investigated the function of TAs containing RNA-binding pentatricopeptide repeats using selective mitoribosome profiling and cryo-electron microscopy (cryo-EM) structural analysis. These analyses show that TAs exhibit strong selectivity for mitoribosomes initiating on their target transcripts. Moreover, TA-mitoribosome footprints indicate that TAs recruit mitoribosomes proximal to the start codon. Two cryo-EM structures o

SUBMITTER: Bridgers JB 

PROVIDER: S-EPMC12916500 | biostudies-literature | 2026 Feb

REPOSITORIES: biostudies-literature