Methyltransferase that can methylate proteins and, to a lower extent, arsenic (  ). Catalytic subunit of a heterodimer with TRMT112, which monomethylates 'Lys-12' of histone H4 (H4K12me1), a modification present at the promoters of numerous genes encoding cell cycle regulators . Catalytic subunit of a heterodimer with TRMT112, which catalyzes N5-methylation of Glu residue of proteins with a Gly-Gln-Xaa-Xaa-Xaa-Arg motif ( ). Methylates ETF1 on 'Gln-185'; ETF1 needs to be complexed to ERF3 in its GTP-bound form to be efficiently methylated ( , ). May also play a role in the modulation of arsenic-induced toxicity by mediating the conversion of monomethylarsonous acid (3+) into the less toxic dimethylarsonic acid (, ). It however only plays a limited role in arsenic metabolism compared with AS3MT .
Subcellular locations: Nucleus
Widely expressed, with highest expression in parathyroid and pituitary glands, followed by adrenal gland and kidney, and lowest expression in leukocytes and mammary gland.