Phosphatase which shows a preference for 4'-phosphopantetheine and its oxidatively damaged forms (sulfonate or S-sulfonate), providing strong indirect evidence that the phosphatase activity pre-empts damage in the coenzyme A (CoA) pathway. Hydrolyzing excess 4'-phosphopantetheine could constitute a directed overflow mechanism to prevent its oxidation to the S-sulfonate, sulfonate, or other forms. Hydrolyzing 4'-phosphopantetheine sulfonate or S-sulfonate would forestall their conversion to inactive forms of CoA and acyl carrier protein. May play a role in the physiological regulation of CoA intracellular levels. (R)-4'-phosphopantetheine + H2O = (R)-pantetheine + phosphate (R)-4'-phosphopantetheine sulfonate + H2O = (R)-pantetheine sulfonate + phosphate (R)-4'-phospho-S-sulfopantetheine + H2O = (R)-S-sulfopantetheine + phosphate Activity is strongly promoted by Co(2+), Ni(2+), Mg(2+) and Mn(2+). Activity is inhibited by EDTA. Homodimer. Interacts with PKM. Expressed in liver, kidney, brain cortex and eye lens (at protein level). Subfamily II proteins have an EGMGR motif about 50 residues from the C-terminus (By similarity). This motif lies near the metal-binding residues in the putative substrate-binding cleft 2 (By similarity). Subfamily II proteins occur only in eukaryotes, in two forms: as a stand-alone unit in plants, and as a C-terminal domain of pantothenate kinases in plants, animals, and chytrid fungi (By similarity). Knockout mice have a body weight and a lifespan similar to wild-type animals. About 10% of the animals start developing cataract at 2 months. At 15 months, 50% homozygous animals are affected. Heterozygous animals develop cataract later, with 10% animals affected at 9 months and 25% at 15. In the N-terminal section; belongs to the type II pantothenate kinase family. In the C-terminal section; belongs to the damage-control phosphatase family. Phosphopantetheine phosphatase II subfamily. Despite belonging to the type II pantothenate kinase family, the pantothenate kinase domain contains a Val residue at position 147 and a Trp residue at position 211 instead of the two conserved active site residues, Glu and Arg. Lacks pantothenate kinase activity.