Figure 1.

The N-linked oligosaccharide structure. The core oligosaccharide is added onto side chains of asparagine residues in a specific sequon (N = asparagine, X = any amino acid but proline, S/T = serine or threonine). It is composed of three glucose (triangles), nine mannose (circles) and two N-acetylglucosamine (squares) residues. Removable α1,2-linked mannose residues are shown in dark green. Letters a-n are assigned to each saccharide and A–C define the oligosaccharide branch. The linkage between individual saccharides is shown.