Mitochondrial rRNA methyltransferase 3 (MRM3)

Mitochondrial rRNA methyltransferase 3 (MRM3) is a mitochondrial enzyme encoded by the human *MRM3* gene, located in the mitochondrial matrix[2][3][4]. MRM3 is an S-adenosyl-L-methionine-dependent 2'-O-ribose methyltransferase that specifically methylates guanosine at position 1370 (G1370) on the 16S mitochondrial large subunit ribosomal RNA (mtLSU rRNA)[2][1]. This 2'-O-methylguanosine modification is conserved and located within the A-loop of the mtLSU rRNA, a region essential for the peptidyl transferase center in mitochondrial ribosomes[1][2]. This modification is critical for proper assembly of the mitochondrial ribosomal large subunit, integrity of the mitoribosome, and efficient mitochondrial translation[1][2]. Loss of MRM3 impairs mitochondrial protein synthesis, disrupts oxidative phosphorylation (OXPHOS), and diminishes cellular respiratory function, linking its dysfunction to mitochondrial disease phenotypes[1][2]. Other aliases for MRM3 include RNMTL1, RMTL1, and 16S rRNA (guanosine(1370)-2'-O)-methyltransferase[2][3]. There are currently no characterized small molecule drugs or inhibitors directly targeting MRM3, and its essential role in mitochondrial translation raises significant safety concerns regarding potential mitochondrial toxicity if therapeutically modulated[1][2].

Other names

RNMTL1rRNA methyltransferase 3, mitochondrialRNA methyltransferase-like protein 1RMTL116S rRNA (guanosine(1370)-2'-O)-methyltransferase16S rRNA [Gm1370] 2'-O-methyltransferaseHC90FLJ10581putative RNA methyltransferase