MTH1 (human MutT Homolog 1) is a purine nucleoside triphosphatase enzyme and belongs to the Nudix hydrolase family. In mammalian systems, MTH is a major detoxifier of the oxidized DNA precursors, 8-oxo-dGTP, 8-oxo-dATP, and 2-OH-dATP and prevents the misincorporation of these purine nucleoside triphosphates into DNA and the subsequent occurrence of A:T pairs to C:G and G:C to T:A pair transversions. The MTH enzyme can also hydrolyze the corresponding ribonucleotides, 8-oxo-GTP, 8-oxo-ATP, and 2-OH-ATP.
