M. Furuichi et al., GENOMIC STRUCTURE AND CHROMOSOME LOCATION OF THE HUMAN MUTT HOMOLOG GENE MTH1 ENCODING 8-OXO-DGTPASE FOR PREVENTION OF A-T TO C-G TRANSVERSION, Genomics, 24(3), 1994, pp. 485-490
8-Oxo-dGTP (8-oxo-7,8-dihydrodeoxyguanosine triphosphate) is produced
by active oxygen species in the nucleotide pool of the cell and can be
incorporated into cellular DNA. Human cells contain enzyme activity t
hat hydrolyzes 8-oxo-dGTP to 8-oxo-dGMP, thereby preventing occurrence
of mutations, caused by misincorporation. When the cDNA for human 8-o
xo-dGTPase was expressed in Escherichia coli mutT(-) mutant cells devo
id of self 8-oxo-dGTPase activity, the elevated level of spontaneous A
:T to C:G mutation frequency reverted to normal. We isolated the genom
ic sequence encoding the enzyme and named the gene MTR1 (for mutT huma
n homologue). This gene is composed of at least 4 exons, spans approxi
mately 9 kb, and is located on human chromo some 7p22. (C) 1994 Academ
ic Press,Inc