MRM3 (RNMTL1) associates with the large mitochondrial ribosomal subunit and transfers a methyl group from S-adenosylmethionine to the 2' hydroxyl group of guanosine-1370 of 16S rRNA (Lee et al. 2013, Lee and Bogenhagen 2014). Inactivation of RNMTL1 causes aberrant assembly of large ribosomal subunits, decreased mitochondrial translation, and respiratory incompetence (Rorbach et al. 2014).
rRNA (guanosine-2'-O-)-methyltransferase activity of RNMTL1 [mitochondrial matrix]