5'-Nucleotidase, Mitochondrial (NT5M)

The NT5M gene encodes a mitochondrial deoxyribonucleotidase with a role in the regulation of the intramitochondrial deoxythymidine triphosphate (dTTP) pool necessary for the synthesis of mitochondrial DNA.The deduced 228-amino acid sequence of DNT2 is 52% identical to that of cytosolic deoxyribonucleotidase (DNT1). The 2 enzymes share many catalytic properties, but DNT2 shows a narrower substrate specificity. Rampazzo et al. (2000) demonstrated mitochondrial localization of DNT2 by the mitochondrial fluorescence of cells expressing a DNT2-green fluorescent protein (GFP) fusion protein. 293 cells expressing fusion proteins without a leader peptide or with DNT1 showed a cytosolic fluorescence. During in vitro import into mitochondria, the preprotein lost the leader peptide.