Transfer of N-glycan to the protein

The 14-sugar N-glycan precursor, synthesized in the previous reactions, is attached in a single step to a nascent protein, releasing the dolichyl phosphate anchor and the as yet unfolded glycoprotein. The reaction occurs cotranslationally as the growing peptide chain leaves a ribosome associated with the ER membrane and enters the ER lumen. This reaction is catalyzed by the OST complex, composed of at least seven proteins; DAD1, DDOST (OST48 in yeast), RPN1 (ribophorin 1), RPN2 (ribophorin 2), OST4, TUSC3 (N33), and either STT3A or STT3B, which contain the catalytic domain (Kelleher DJ and Gilmore R, 2006). A mutation in RPN2 is associated with CDG-Ix (Vleugels W et al, 2009).<br>The signal for glycosylation is the consensus sequence Asn - X - Thr/Ser, where the first amino acid is always Asn, the second can be any amino acid except for Pro, and the third position may be Thr, Ser or Cys, with a preference for the first (Breuer W et al, 2001). Not all Asn - X - Thr/Ser sites are modified in vivo (Petrescu AJ et al, 2004).<br> Reviewed: Gagneux, P, 2010-04-16 Edited: Jassal, B, 2009-11-10 Authored: Dall'Olio, GM, 2009-11-10

http://purl.obolibrary.org/obo/HINO_0025386

The 14-sugar N-glycan precursor, synthesized in the previous reactions, is attached in a single step to a nascent protein, releasing the dolichyl phosphate anchor and the as yet unfolded glycoprotein. The reaction occurs cotranslationally as the growing peptide chain leaves a ribosome associated with the ER membrane and enters the ER lumen. This reaction is catalyzed by the OST complex, composed of at least seven proteins; DAD1, DDOST (OST48 in yeast), RPN1 (ribophorin 1), RPN2 (ribophorin 2), OST4, TUSC3 (N33), and either STT3A or STT3B, which contain the catalytic domain (Kelleher DJ and Gilmore R, 2006). A mutation in RPN2 is associated with CDG-Ix (Vleugels W et al, 2009).
The signal for glycosylation is the consensus sequence Asn - X - Thr/Ser, where the first amino acid is always Asn, the second can be any amino acid except for Pro, and the third position may be Thr, Ser or Cys, with a preference for the first (Breuer W et al, 2001). Not all Asn - X - Thr/Ser sites are modified in vivo (Petrescu AJ et al, 2004).

Reviewed: Gagneux, P, 2010-04-16

Edited: Jassal, B, 2009-11-10

Authored: Dall'Olio, GM, 2009-11-10

Reactome, http://www.reactome.org

Pubmed11470266

Pubmed16317064

Pubmed19835842

Pubmed14514716

http://purl.obolibrary.org/obo/HINO_0008737

http://purl.obolibrary.org/obo/CHEBI_53019

http://purl.obolibrary.org/obo/CHEBI_16214

http://purl.obolibrary.org/obo/HINO_0008550

Transfer of N-glycan to the protein

HINO:0025386

Transfer of N-glycan to the protein

ReactomeREACT_22208

EC Number: 2.4.1.119

Reactome Database ID Release 43446209

http://purl.obolibrary.org/obo/INO_0000040