Broad specificity cytosolic 5'-nucleotidase that catalyzes the dephosphorylation of 6-hydroxypurine nucleoside 5'-monophosphates. In addition, possesses a phosphotransferase activity by which it can transfer a phosphate from a donor nucleoside monophosphate to an acceptor nucleoside. Through these activities regulates the purine nucleoside/nucleotide pools within the cell. a ribonucleoside 5'-phosphate + H2O = a ribonucleoside + phosphate a 2'-deoxyribonucleoside + a ribonucleoside 5'-phosphate = a 2'-deoxyribonucleoside 5'-phosphate + a ribonucleoside Binds 1 Mg(2+) ion per subunit. Homotetramer. Belongs to the 5'(3')-deoxyribonucleotidase family.