Table 2. Experimentally characterized glycan linkages at known glycosites of bacteria and archaea.
| Sugar linkage | Class | Example glycoproteins |
| N-LINKED GLYCANS/ARCHAEA | ||
| Glc-Asn | Halobacteria | Flagellin, Slg |
| βGalNAc- Asn, | Halobacteria, Methanococci, Methanobacteria Thermoprotei | Flagellin, Slg, Cytochrome subunit |
| N-LINKED GLYCANS/BACTERIA | ||
| Bac-Asn | Epsilonproteobacteria | AcrA, PEB3, CgpA, HisJ, ZnuA, jlpA etc. |
| GlcNAc-Asn | Deltaproteobacteria | HmcA |
| Hexose-Asn, dihexose-Asn, Glu-Asn,Gal-Asn | Gammaproteobacteria | Adhesins |
| O-LINKED GLYCANS/BACTERIA | ||
| Man-Ser/Thr | Actinobacteria, Flavobacteria, Sphingobacteria | Glycosidases, Cell surface lipoproteins,Secreted antigens, Superoxide dismutase, Heparinase, Chondroitinase etc. |
| Fucose | Bacteroidia | Putative cell division proteins, exported proteins, outer membrane proteins etc. |
| β-GalNAc-Ser/Thr | Bacilli | Slg |
| β-D-Gal-Ser/Thr | Bacilli | Slg, SgsE, SgtA etc. |
| β-GlcNAc-Ser/Thr, HexNAc | Bacilli | Glycocin F, Flagellin |
| Bac/DATDH-Ser | Betaproteobacteria | Pilin, CcoP, CycB etc. |
| FucNAc-Ser | Gammaproteobacteria | Pilin |
| Rha-Ser/Thr, Deoxyhexose-Ser | Gammaproteobacteria | Flagellin |
Footnotes: Detailed information about attached glycan and glycoproteins can be obtained from www.proglycprot.org).