MRM1 (mitochondrial rRNA methyltransferase 1) is a mitochondrial enzyme that catalyzes the 2'-O-methylation of guanosine at position 1145 (Gm1145) in the 16S mitochondrial large subunit ribosomal RNA (mtLSU rRNA) 1. This modification occurs in the peptidyl transferase domain, a universally conserved region critical for protein synthesis. MRM1 functions as an S-adenosyl-L-methionine-dependent methyltransferase and localizes to mitochondrial nucleoids 1. The enzyme plays a crucial role in mitochondrial ribosome biogenesis and cellular stress responses. MRM1 has been identified as a high-copy suppressor of ER stress-mediated cell death in yeast, contributing to enhanced mitochondrial biogenesis and improved electron transport chain efficiency 2. Additionally, MRM1 is regulated by the transcriptional coactivator PGC-1α and its partner ERRα in skeletal muscle, suggesting involvement in metabolic regulation 3. Disease relevance includes potential causative associations with amyotrophic lateral sclerosis (ALS) identified through Mendelian randomization analysis 4. The gene is located within the 17q12 region, and microdeletions encompassing MRM1 have been associated with renal abnormalities in clinical cases 5. These findings highlight MRM1's importance in mitochondrial function, cellular stress resistance, and potential neurological disease pathogenesis.