Aminoacyl-tRNA surveillance by EF-Tu in mammalian mitochondria.

ABSTRACT

Aminoacyl-tRNA synthetases specifically recognize their cognate tRNAs and ensure the accuracy of translation. However, in mammalian mitochondria, seryl-tRNA synthetase (mt SerRS) significantly misacylates tRNA(Gln), indicating the presence of another mechanism to be required to maintain the fidelity of mitochondrial protein synthesis. We have revealed that mammalian mitochondrial elongation factor Tu (mt EF-Tu) tends to interact with seryl-tRNA(Gln) with lower affinity than glutaminyl-tRNA(Gln) and seryl-tRNA(Ser). This result proposes that mt EF-Tu has a critical role to maintain the translational fidelity by surveillance of aminoacyl-tRNAs for quality control.