EC 2.4.99.18 - Dolichyl-diphosphooligosaccharide—protein glycotransferase

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IntEnz Enzyme Nomenclature
EC 2.4.99.18

Names

Accepted name:
dolichyl-diphosphooligosaccharide—protein glycotransferase
Other names:
asparagine N-glycosyltransferase
dolichyldiphosphooligosaccharide—protein glycosyltransferase
dolichyldiphosphooligosaccharide—protein oligosaccharyltransferase
dolichyldiphosphoryloligosaccharide—protein oligosaccharyltransferase
dolichylpyrophosphodiacetylchitobiose—protein glycosyltransferase
oligomannosyltransferase
oligosaccharide transferase
dolichyl-diphosphooligosaccharide:protein-L-asparagine oligopolysaccharidotransferase
STT3
Systematic name:
dolichyl-diphosphooligosaccharide:protein-L-asparagine N-β-D-oligopolysaccharidotransferase

Reactions

Comments:

Occurs in eukaryotes that form a glycoprotein by the transfer of a glucosyl-mannosyl-glucosamine polysaccharide to the side-chain of an L-asparagine residue in the sequence -Asn-Xaa-Ser- or -Asn-Xaa-Thr- (Xaa not Pro) in nascent polypeptide chains. The basic oligosaccharide is the tetradecasaccharide Glc3Man9GlcNAc2. However, smaller oligosaccharides derived from it and oligosaccharides with additional monosaccharide units attached may be involved. See ref [2] for a review of N-glycoproteins in eukaryotes. Man3GlcNAc2 seems to be common for all of the oligosaccharides involved with the terminal N-acetylglucosamine linked to the protein L-asparagine. Occurs on the cytosolic face of the endoplasmic reticulum. The dolichol involved normally has 14-21 isoprenoid units with two trans double-bonds at the ω end, and the rest of the double-bonds in cis form.

Links to other databases

Enzymes and pathways: NC-IUBMB , BRENDA , ExplorEnz , ENZYME@ExPASy , KEGG , MetaCyc , UniPathway
Protein domains and families: PROSITE:PDOC00172
Structural data: CSA , EC2PDB
CAS Registry Number: 75302-32-8
UniProtKB/Swiss-Prot: (68) [show] [UniProt]

References

  1. Das, R.C. and Heath, E.C.
    Dolichyldiphosphoryloligosaccharide-protein oligosaccharyltransferase; solubilization, purification, and properties.
    Proc. Natl. Acad. Sci. USA 77: 3811-3815 (1980). [PMID: 6933437]
  2. Song, W., Henquet, M. G., Mentink, R. A., van Dijk, A. J., Cordewener, J. H., Bosch, D., America, A. H., van der Krol, A. R.
    N-glycoproteomics in plants: perspectives and challenges.
    J Proteomics 74: 1463-1474 (2011). [PMID: 21605711]

[EC 2.4.99.18 created 1984 as EC 2.4.1.119, transferred 2012 to EC 2.4.99.18]