Ilgin Eser Kotan

Abstract The human mitochondrial genome encodes 13 subunits of the oxidative phosphorylation system essential for energy metabolism to drive cellular activities. Translation of 11 mRNAs by membrane-bound ribosomes is coupled to insertion of the nascent polypeptides into the inner membrane aided by the OXA1L insertase. To this end, the mechanism of membrane insertion of nascent polypeptides and the functional link to the translation process are not sufficiently understood.

Keywords NAC nascent chain ribosome chaperone co-translational protein folding proteostasis ribosome profiling single-molecule microscopy cryo-electron microscopy optical tweezers Introduction To achieve biological activity, newly synthesized proteins must adopt their native structures, undergo N-terminal processing, and be targeted to specific cellular compartments.

Abstract Cotranslational protein folding depends on general chaperones that engage highly diverse nascent chains at the ribosomes. Here we discover a dedicated ribosome-associated chaperone, Chp1, that rewires the cotranslational folding machinery to assist in the challenging biogenesis of abundantly expressed eukaryotic translation elongation factor 1A (eEF1A).