Oxygen radicals damage chromosomal DNA causing cell death and inducing mutations. Among the various classes of DNA damage caused by oxygen radicals, an oxidized form of guanine base (8-oxoguanine) appears to be important as it can pair with cytosine and adenine and G:C to T:A transversion mutation occurs. A significant amount of 8-OxoG is formed in the chromosomal DNA of mammalian cells, with most damaged nucleotides excised from the DNA and excreted in the urine. Along with 8-oxoG being present in oxidatively damaged DNA, 8-oxo-deoxyguanosine (8-oxo-dGTP) is formed in the nucleotide pool during normal cellular metabolism and following oxidative stress. The 8-oxo-dGTP nucleotide can be incorporated in DNA during polymerization and can result in a mispairing unless repaired. MTH converts 8-oxo-dGTP in the nucleotide pool to the monophosphate and prevents the misincorporation of 8-oxo-dGTP into DNA (Figure courtesy of Dr. Mark Kelley). MTH also recognizes 8-oxo-rGTP, which could incorporate into RNA during gene transcription leading to missense or nonsense protein production.
2-hydroxy-dATP diphosphatase; 7,8-dihydro-8-oxoguanine triphosphatase; 8-oxo-7,8-dihydrodeoxyguanosine triphosphatase; 8-oxo-7,8-dihydroguanosine triphosphatase; 8-oxo-dGTPase; mutT human homolog 1; Nucleoside Diphosphate Linked Moiety X Motif 1; Nucleoside diphosphate-linked moiety X motif 1; nucleoside diphosphate-linked moiety X-type motif 1; nudix (nucleoside diphosphate linked moiety X)-type motif 1; NUDIX Motif 1; NUDT1