Bouzaidi-Tiali, Nabile Aeby, Eric Charrière, Fabien Pusnik, Mascha Schneider, André 2007-09-13 Mitochondrial tRNA import is widespread in eukaryotes. Yet, the mechanism that determines its specificity is unknown. Previous <i>in vivo</i> experiments using the tRNAs^Met, tRNA^Ile and tRNA^Lys have suggested that the T-stem nucleotide pair 51:63 is the main localization determinant of tRNAs in <i>Trypanosoma brucei</i>. In the cytosol-specific initiator tRNA^Met, this nucleotide pair is identical to the main antideterminant that prevents interaction with cytosolic elongation factor (eEF1a). Here we show that ablation of cytosolic eEF1a, but not of initiation factor 2, inhibits mitochondrial import of newly synthesized tRNAs well before translation or growth is affected. tRNA^Sec is the only other cytosol-specific tRNA in <i>T. brucei</i>. It has its own elongation factor and does not bind eEF1a. However, a mutant of the tRNA^Sec expected to bind to eEF1a is imported into mitochondria. This import requires eEF1a and aminoacylation of the tRNA. Thus, for a tRNA to be imported into the mitochondrion of <i>T. brucei</i>, it needs to bind eEF1a, and it is this interaction that mediates the import specificity. application/pdf https://folia.unifr.ch/global/documents/300399 https://folia.unifr.ch/documents/300399/files/schneider_efm.pdf eng info:eu-repo/semantics/altIdentifier/doi/10.1038/sj.emboj.7601857 info:eu-repo/semantics/openAccess License undefined The EMBO Journal. - 2007, vol. 26, no. 20, p. 4302–4312 elongation factor1a mitochondrial biogenesis selenocysteine tRNA tRNA trypanosomes info:eu-repo/classification/udc/57 Elongation factor 1a mediates the specificity of mitochondrial tRNA import in T. brucei http://purl.org/coar/resource_type/c_6501