FIG. 1.

Schematic representation of prokaryotic glycoproteins. (a) Typical long-chain S-layer glycoproteins of organisms belonging to the domain Bacteria. (b) Typical non-S-layer glycoprotein or short-chain S-layer glycoprotein of organisms belonging to the domain Archaea. In either case the glycan chains can be linear or branched (modified from reference 15). Symbols: solid star, possible modification at the nonreducing end; shaded boxes, identical repeating unit; solid box, linkage glycose; checkered boxes, core glycose; boxes with horizontal, diagonal, and vertical lines, individual glycoses of the glycan; open circles, individual amino acids of the polypeptide; solid circle, linkage amino acid.