Paste your sequence alignment and highlight or circle the conserved histidine sequences. Copper is a cofactor required for tyrosinase activity. Copper is added to tyrosinase homodimers in the trans-Golgi network (TGN). There are two binding sites for copper each made up of 3 Histidine residues in the N-terminal ectodomain. Sometimes looking at the sequences of homologous proteins from diverse sequences can help identify conserved regions of proteins. Use BLASTp to align tyrosinase protein sequences and identify the potential conserved Histidines that might form these Copper binding sites. When you want to align two sequences using the BLASTp algorithm you need to check the Align two or more sequences block. Compare the human tyrosinase sequence to the tyrosinase sequence from other species (eg. Japanese Ricefish [Oryias latipes], NP_001098272.1 E or Steptomyces antibioticus, WP_059197092.1 ). Edit View Insert Format Tools Table 12pt Preformatted v B IUA Query 9 Sbjct 10 Sbjct 70 Query 129 sbjct 130 T V LL