ID 3.6.1.70 DE guaosine-5'-diphospho-5'-[DNA] diphosphatase. AN aprataxin. AN pp5'G5'DNA diphosphatase. AN pp5'G5'-DNA guanylate hydrolase. CA a 5'-end guanosine-5'-diphospho-5'-(2'-deoxyribonucleoside)-DNA + H2O = CA a 5'-end 5'-monophospho-2'-deoxyribonucleoside-DNA + GMP + 2 H(+). CC -!- Aprataxin is a DNA-binding protein that catalyzes (among other CC activities) the 5' decapping of Gpp-DNA (formed by homologs of RtcB3 CC from the bacterium Myxococcus xanthus). CC -!- The enzyme binds the guanylate group to a histidine residue at its CC active site, forming a covalent enzyme-nucleotide phosphate CC intermediate, followed by the hydrolysis of the guanylate from the CC nucleic acid and eventual release. CC -!- The enzyme forms a 5'-phospho terminus that can be efficiently joined CC by 'classical' ligases. CC -!- The enzyme also possesses the activity of EC 3.6.1.71 and CC EC 3.6.1.72. CC -!- Formerly EC 3.1.11.8. //