. "Cytosolic 5'3'-nucleotidase (NT5C) catalyzes the hydrolysis of deoxy- and ribo- guanosine and inosine nucleoside monophosphates to yield the corresponding nucleosides and orthophosphate. The active form of the enzyme is a homodimer, with an absolute requirement for Mg++ (Hoglund and Reichard 1990; Rampazzo et al. 2000). This enzyme appears to play a central role in the \"substrate cycles\" that regulate cytosolic deoxynucleotide levels (Gazziola et al. 2001)."^^ . . . . . . . . "(d)GMP or (d)IMP + H2O => (d)G or (d)I + orthophosphate [NT5C]"^^ . "3.1.3.5"^^ . . . . .