The predicted amino acid sequence of human Sn shows a high degree of similarity to mouse Sn.

The hydrophobic leader peptide (amino acids 1-19) and transmembrane region (1642-1662) are underlined. Potential N-linked glycosylation sites are boxed in black. The conserved cysteine residues in domains 1 and 2 characteristic of Siglecs are boxed in gray. Residues in domain 1 that interact with sialic acid are boxed in white. The Ig domain boundaries, deduced from the exon-intron boundaries of the mouse Sn gene,63 are indicated. Residues that are identical with the mouse ortholog are indicated by stars; residues that are similar are indicated by dashes; and residues that are not represented in mouse Sn are indicated by open circles. The cDNA sequence of human Sn has been assigned the GenBank accession number AF230073.