Catalyzes the reversible cleavage of pseudouridine 5'-phosphate (PsiMP) to ribose 5-phosphate and uracil. Functions biologically in the cleavage direction, as part of a pseudouridine degradation pathway. D-ribose 5-phosphate + uracil = H2O + psi-UMP Binds 1 manganese ion per subunit. Can also use Fe(2+) and Co(2+). The unusual metal binding site is heavily hydrated, coordinated with an aspartate side chain and five water molecules, and likely plays a role in anchoring the PsiMP phosphate. Inhibited by Zn(2+) and Ni(2+). kcat is 3.74 sec(-1) for the synthesis of PsiMP. Homotrimer. Belongs to the pseudouridine-5'-phosphate glycosidase family.