GMP (guanosine monophosphate) reductase catalyses the irreversible and NADPH-dependent reductive deamination of GMP into IMP.NADPH + guanosine 5-phosphate = NADP+ + inosine 5-phosphate + NH3 It converts nucleobase, nucleoside and nucleotide derivatives of G to A nucleotides, and maintains intracellular balance of A and G nucleotides. A deep split separates two families of GMP reductase. This family includes both eukaryoticand some proteobacterial sequences.
