Meta-Biol

• Pathways

Inorganic arsenic (iAs) compounds are human carcinogens. The most toxic arsenic metabolite is monomethylarsonous acid (MMAIII). Arsenic (3+) methyltransferase (AS3MT) is the primary enzyme responsible for methylating MMAIII to the less toxic dimethylarsonic acid (DMAA). A human ortholog of yeast MTQ2, HemK methyltransferase family member 2 (aka N(6)-adenine-specific DNA methyltransferase 1, N6AMT1), is also able to methylate MMAIII using S-adenosyl L-methionine as methyl donor (Ren et al. 2011). N6AMT1 forms a heterodimer with multifunctional methyltransferase subunit TRM112-like protein (TRMT112) (Figaro et al. 2008).