We have isolated cDNAs for the human TRP-2 gene which represents a third member of the tyrosinase-related gene family and encodes the dopachrome tautomerase activity that functions in the synthesis of melanin pigment. The human TRP-2 protein has 83% identity/90% similarity to the mouse sequence and has all the structural characteristics of the tyrosinase protein family, including a signal peptide, 15 conserved cysteine residues, two copper-binding domains and a C-terminal membrane-spanning region. Northern blot analysis reveals that TRP-2 is expressed at high levels in human melanoma cells.