Nucleotidase that shows the greatest phosphatase activity on purine (deoxy)nucleoside 5'-monophosphates, particularly the substrates 5'-GMP, 5'-AMP and 2'-deoxy-5'-AMP. a ribonucleoside 5'-phosphate + H2O = a ribonucleoside + phosphate a 2'-deoxyribonucleoside 5'-phosphate + H2O = a 2'-deoxyribonucleoside + phosphate GMP + H2O = guanosine + phosphate AMP + H2O = adenosine + phosphate dAMP + H2O = 2'-deoxyadenosine + phosphate Binds 1 divalent metal cation per subunit. Most active with Co(2+), and may utilize Mg(2+) or Mn(2+), though with less activity. Optimum temperature is above 90 degrees Celsius. Homodimer. Belongs to the SurE nucleotidase family. Was originally annotated as an acid phosphatase (EC 3.1.3.2).