Selection of initiator tRNA and start codon by mammalian mitochondrial initiation factor 3 in leaderless mRNA translation.

ABSTRACT: The mammalian mitochondrial protein synthesis system produces 13 essential subunits of oxidative phosphorylation (OXPHOS) complexes. Translation initiation in mammalian mitochondria is characterized by the use of leaderless messenger RNAs (mRNAs) and non-AUG start codons, where the proofreading function of IF-3mt still remains elusive. Here, we developed a reconstituted mammalian mitochondrial translation system using in vitro transcribed and native mitochondrial transfer RNAs (tRNAs) to investigate IF-3mt's proofreading function. Similar to bacterial IF-3, IF-3mt permits an initiator tRNA to participate in initiation by discriminating the three G-C pairs in its anticodon stem, and by the cognate interactions of its anticodon with the AUG start codon. As a result, IF-3mt promotes the accur

SUBMITTER: Lee M 

PROVIDER: S-EPMC11775629 | biostudies-literature | 2025 Jan

REPOSITORIES: biostudies-literature