{PDOC00001} {PS00001; ASN_GLYCOSYLATION} {BEGIN} ************************ * N-glycosylation site * ************************ It has been known for a long time [1] that potential N-glycosylation sites are specific to the consensus sequence Asn-Xaa-Ser/Thr. It must be noted that the presence of the consensus tripeptide is not sufficient to conclude that an asparagine residue is glycosylated, due to the fact that the folding of the protein plays an important role in the regulation of N-glycosylation [2]. It has been shown [3] that the presence of proline between Asn and Ser/Thr will inhibit N-glycosylation; this has been confirmed by a statistical analysis of glycosylation sites [4], which also shows that about 50% of the sites that have a proline C-terminal to Ser/Thr are not glycosylated. It must also be noted that there are a few reported cases of glycosylation sites with the pattern Asn-Xaa-Cys; an experimentally demonstrated occurrence of such a non-standard site is found in the plasma protein C [5]. -Consensus pattern: N-{P}-[ST]-{P} [N is the glycosylation site] -Last update: May 1991 / Text revised. [ 1] Marshall R.D. "Glycoproteins." Annu. Rev. Biochem. 41:673-702(1972). PubMed=4563441; DOI=10.1146/annurev.bi.41.070172.003325 [ 2] Pless D.D., Lennarz W.J. "Enzymatic conversion of proteins to glycoproteins." Proc. Natl. Acad. Sci. U.S.A. 74:134-138(1977). PubMed=264667 [ 3] Bause E. "Structural requirements of N-glycosylation of proteins. Studies with proline peptides as conformational probes." Biochem. J. 209:331-336(1983). PubMed=6847620 [ 4] Gavel Y., von Heijne G. "Sequence differences between glycosylated and non-glycosylated Asn-X-Thr/Ser acceptor sites: implications for protein engineering." Protein Eng. 3:433-442(1990). PubMed=2349213 [ 5] Miletich J.P., Broze G.J. Jr. "Beta protein C is not glycosylated at asparagine 329. The rate of translation may influence the frequency of usage at asparagine-X-cysteine sites." J. Biol. Chem. 265:11397-11404(1990). PubMed=1694179 -------------------------------------------------------------------------------- PROSITE is copyrighted by the SIB Swiss Institute of Bioinformatics and distributed under the Creative Commons Attribution-NonCommercial-NoDerivatives (CC BY-NC-ND 4.0) License, see https://prosite.expasy.org/prosite_license.html -------------------------------------------------------------------------------- {END}