Mitochondrial S-adenosyl-L-methionine-dependent methyltransferase that catalyzes the formation of 5-methyl-uridine in tRNAs and 12S rRNA (, ). Catalyzes the methylation of uridine at position 54 (m5U54) in all tRNAs . Specifically methylates the uridine in position 429 of 12S rRNA (m5U429) . Does not affect RNA stability or mitochondrial translation .
Subcellular locations: Mitochondrion
Subcellular locations: Mitochondrion matrix