Fig. 2.

Amino acid sequence alignments for mammalian IDS N-terminus sequences. See Table 1 for sources of IDS sequences; asterisk shows identical residues for IDS subunits; colon similar alternate residues; dot dissimilar alternate residues; the active site residues (for human IDS) are shown in blue; leader peptide is in brown; propeptide in red; bold underlined font shows residues corresponding to known or predicted exon start sites; exon numbers refer to human IDS gene exons