Catalytic subunit of a heterodimer with TRMT112, which specifically methylates the 6th position of adenine in position 1832 of 18S rRNA (By similarity). 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 (By similarity). 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. Expressed from 20 minutes after fertilization in embryos. Microcephaly and curved tails. Belongs to the methyltransferase superfamily. PrmA family.