| Type: | Family | Name: | Bis(5'-nucleosyl)-tetraphosphatase |
| Description: | MutT is a small bacterial protein (~12-15kDa) involved in the GO system [] 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 withnear equal efficiency, leading to A.T to G.C transversions. MutT specifically degrades 8-oxo-dGTP to the monophosphate, with the concomitantrelease of pyrophosphate. A short conserved N-terminal region of mutT (designated the MutT domain) is also found in a variety of otherprokaryotic, viral, and eukaryotic proteins [, , , ]. Recently, the genericname `NUDIX hydrolases' (NUcleoside DIphosphate linked to some other moeity X) has been coined for this domain family [].The enzyme diadenosine 5',5''-P1,P4-tetraphosphate pyrophosphohydrolase asymmetrically hydrolyses AP4A to yield AMP and ATP. The catalysed reactionis as follows: P(1),P(4)-bis(5'-adenosyl)tetraphosphate + H(2)O = ATP + AMP.The cDNA and derived amino acid sequence of human diadenosine 5',5"'- P1,P4-tetraphosphate pyrophosphohydrolase have been determined by means ofEST analysis []. The protein possesses a modification of the MutT domain found in certain nucleotide pyrophosphatases. | Short Name: | Tetra_PHTase |
