MRM2 (FTSJ2) located in foci near mitochondrial nucleoids (Lee et al. 2013) transfers a methyl group from S-adenosylmethionine to the 2' hydroxyl of uridine-1369 in 16S rRNA (Lee and Bogenhagen 2014, Rorbach et al. 2014). Inactivation of FTSJ2 causes aberrant assembly of large mitochondrial subunits, reduced mitochondrial translation, and respiratory incompetence (Rorbach et al. 2014).