5"-Nucleotidase Domain Containing Protein 4 (NT5DC4)

NT5DC4 Belongs to the 5"""(3""")-deoxyribonucleotidase family. Three cytosolic and one plasma membrane-bound 5′-nucleotidases have been cloned and characterized. Their various substrate specificities suggest widely different functions in nucleotide metabolism. A 5′-nucleotidase in mitochondria. The enzyme, named dNT-2, dephosphorylates specifically the 5′- and 2′(3′)-phosphates of uracil and thymine deoxyribonucleotides. The cDNA of human dNT-2 codes for a 25.9-kDa polypeptide with a typical mitochondrial leader peptide, providing the structural basis for two-step processing during import into the mitochondrial matrix. The deduced amino acid sequence is 52% identical to that of a recently described cytosolic deoxyribonucleotidase (dNT-1). The two enzymes share many catalytic properties, but dNT-2 shows a narrower substrate specificity.