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).