Catalytic subunit of a heterodimer with TRMT112, which specifically methylates the 6th position of adenine in position 1832 of 18S rRNA (PubMed:31328227, PubMed:32217665, PubMed:33357433, PubMed:33428944, PubMed:35033535). N6-methylation of adenine(1832) in 18S rRNA resides in the decoding center of 18S rRNA and is required for translation and embryonic stem cells (ESCs) pluripotency and differentiation (PubMed:33357433). adenosine(1832) in 18S rRNA + S-adenosyl-L-methionine = H(+) + N(6)-methyladenosine(1832) in 18S rRNA + S-adenosyl-L-homocysteine rRNA N6-adenosine-methyltransferase activity is inhibited by zinc. kcat is 13.1 h(-1) for 18S rRNA (PubMed:33428944). kcat is 17.6 h(-1) for S-adenosyl-L-methionine (PubMed:33428944). Heterodimer; heterodimerizes with TRMT112. Expressed from very early development (8 post-conceptual weeks) and expression persists through adulthood in multiple substructures of the brain, including the cerebellar cortex, hippocampus, and striatum. The disease is caused by variants affecting the gene represented in this entry. Belongs to the methyltransferase superfamily. PrmA family.