EC Explorer

3.6.1.70

guanosine-5′-diphospho-5′-[DNA] diphosphatase

guanosine-5′-diphospho-5′-[DNA] + H₂O = phospho-5′-[DNA] + GMP

aprataxin, pp5′G5′DNA diphosphatase, pp5′G5′-DNA guanylate hydrolase, APTX (gene name), HNT3 (gene name)

guanosine-5′-diphospho-5′-[DNA] hydrolase (guanosine 5′-phosphate-forming)

Aprataxin is a DNA-binding protein that catalyses (among other activities) the 5′ decapping of Gpp-DNA (formed by homologs of RtcB3 from the bacterium Myxococcus xanthus). The enzyme binds the guanylate group to a histidine residue at its active site, forming a covalent enzyme-nucleotide phosphate intermediate, followed by the hydrolysis of the guanylate from the nucleic acid and eventual release. The enzyme forms a 5′-phospho terminus that can be efficiently joined by "classical" ligases. The enzyme also possesses the activitiy of EC 3.6.1.71, adenosine-5′-diphospho-5′-[DNA] diphosphatase and EC 3.6.1.72, DNA-3′-diphospho-5′-guanosine diphosphatase.

created 2017 as EC 3.1.11.8, transferred 2019 to EC 3.6.1.70