DNA repair enzyme that can remove a variety of covalent adducts from DNA through hydrolysis of a 5'-phosphodiester bond, giving rise to DNA with a free 5' phosphate. Catalyzes the hydrolysis of dead-end complexes between DNA and the topoisomerase 2 (top2) active site tyrosine residue. Hydrolyzes 5'-phosphoglycolates on protruding 5' ends on DNA double-strand breaks (DSBs) due to DNA damage by radiation and free radicals (By similarity). Controls gastrulation movements and left/right (L/R) axis determination via smad3-mediated regulation of cdh1/e-cadherin. Regulates the formation of Kupffer's vesicle, a signaling center essential for establishing L/R asymmetry. Modulates smad3 activity through modulating nodal-acvr1/akt4 signaling. Binds 1 magnesium or manganese ion per subunit. Expressed ubiquitously during blastula stages and throughout gastrulation. Shortly after shield formation, expressed weakly in dorsal forerunner cells (DFCs). Between somite stages 5 and 9, expressed in the tailbud and around the Kupffer's vesicle at a higher level than the more uniform expression in the embryo. Expressed both maternally and zygotically. Belongs to the CCR4/nocturin family. TTRAP/TDP2 subfamily. Extended N-terminus.