Aprataxin is a DNA-binding protein that catalyses (among other activities) the 3′ decapping of DNA-ppG (formed by EC 22.214.171.124, 3′-phosphate/5′-hydroxy nucleic acid ligase) . 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 its eventual release. The enzyme also possesses the activity of EC 126.96.36.199, adenosine-5′-diphospho-5′-[DNA] diphosphatase, and EC 188.8.131.52, guanosine-5′-diphospho-5′-[DNA] diphosphatase.
Das, U., Chauleau, M., Ordonez, H. and Shuman, S. Impact of DNA3′pp5′G capping on repair reactions at DNA 3′ ends. Proc. Natl. Acad. Sci. USA111 (2014) 11317–11322. [PMID: 25049385]
Chauleau, M., Jacewicz, A. and Shuman, S. DNA3′pp5′G de-capping activity of aprataxin: effect of cap nucleoside analogs and structural basis for guanosine recognition. Nucleic Acids Res.43 (2015) 6075–6083. [PMID: 26007660]