Involved in nucleotide metabolism: produces dUMP, the immediate precursor of thymidine nucleotides and decreases the intracellular concentration of dUTP to avoid uracil incorporation into viral DNA. dUTP + H2O = diphosphate + dUMP + H(+) Monomer. Belongs to the dUTPase family. BLLF3 is known as BLLF2 in PubMed:6087149.