MutT is a small bacterial protein (~12-15kDa) involved in the GO system [<cite idref="PUB00002202"/>] responsible for removing an oxidatively damaged form of guanine (8-hydroxy- guanine or 7,8-dihydro-8-oxoguanine) from DNA and the nucleotide pool. 8-oxo-dGTP is inserted opposite dA and dC residues of template DNA with near equal efficiency, leading to A.T to G.C transversions. MutT specifically degrades 8-oxo-dGTP to the monophosphate, with the concomitant release of pyrophosphate. A short conserved N-terminal region of mutT (designated the MutT domain) is also found in a variety of other prokaryotic, viral, and eukaryotic proteins [<cite idref="PUB00004433"/>, <cite idref="PUB00003856"/>, <cite idref="PUB00002808"/>, <cite idref="PUB00006677"/>]. Recently, the generic name `NUDIX hydrolases' (NUcleoside DIphosphate linked to some other moeity X) has been coined for this domain family [<cite idref="PUB00006662"/>].<p>DATP pyrophosphohydrolase hydrolyses nucleoside triphosphates with a preference for DATP. The protein sequence shares significant similarity to proteins with a core MutT domain.</p>