Homolog of bacterial ATP-dependent tRNA sulphur transferase MnmA (alias TrmU). Sulfur group originates from cysteine via a cascade of sulphur relay proteins, of which the pyridoxal phosphate-containing cysteine desulfurase Nfs1 plays the same role as IscS in bacteria. At least one other mitochondrial sulfur transport protein remains to be identified (2012). U34 thiolation in mitochondria differs from that in bacteria, which involves IscS (instead of Nfs1) and a cascade of relay proteins TusA,B,C,D,E.
Mitochondria-specific RNA-modifying enzymes responsible for the biosynthesis of the wobble base in mitochondrial tRNAs. Implications for the molecular pathogenesis of human mitochondrial diseases.
Umeda N, Suzuki T, Yukawa M, Ohya Y, Shindo H, Watanabe K, Suzuki T
Mutations in MTO2 related to tRNA modification impair mitochondrial gene expression and protein synthesis in the presence of a paromomycin resistance mutation in mitochondrial 15 S rRNA.