| UniProt Protein Function: | Catalytic subunit of the N-oligosaccharyl transferase (OST) complex which catalyzes the transfer of a high mannose oligosaccharide from a lipid-linked oligosaccharide donor to an asparagine residue within an Asn-X-Ser/Thr consensus motif in nascent polypeptide chains. N-glycosylation occurs cotranslationally and the complex associates with the Sec61 complex at the channel-forming translocon complex that mediates protein translocation across the endoplasmic reticulum (ER). STT3B is present in a small subset of OST complexes and mediates both cotranslational and post-translational N-glycosylation of target proteins: STT3B-containing complexes are required for efficient post-translational glycosylation and while they are less competent than STT3A-containing complexes for cotranslational glycosylation, they have the ability to mediate glycosylation of some nascent sites that are not accessible for STT3A. STT3B-containing complexes also act post-translationally and mediate modification of skipped glycosylation sites in unfolded proteins. Plays a role in ER-associated degradation (ERAD) pathway that mediates ubiquitin-dependent degradation of misfolded endoplasmic reticulum proteins by mediating N-glycosylation of unfolded proteins, which are then recognized by the ERAD pathway and targeted for degradation. Mediates glycosylation of the disease variant AMYL-TTR 'Asp-38' of TTR at 'Asn-118', leading to its degradation. |
| NCBI Summary: | The protein encoded by this gene is a catalytic subunit of a protein complex that transfers oligosaccharides onto asparagine residues. Defects in this gene are a cause of congenital disorder of glycosylation Ix (CDG1X). [provided by RefSeq, Jun 2014] |
| UniProt Code: | Q8TCJ2 |
| NCBI GenInfo Identifier: | 30578410 |
| NCBI Gene ID: | 201595 |
| NCBI Accession: | NP_849193.1 |
| UniProt Secondary Accession: | Q8TCJ2,Q96JZ4, Q96KY7, |
| UniProt Related Accession: | Q8TCJ2 |
| Molecular Weight: | Calculated MW: 93kDaObserved MW: Refer to figures |
| NCBI Full Name: | dolichyl-diphosphooligosaccharide--protein glycosyltransferase subunit STT3B |
| NCBI Synonym Full Names: | STT3B, catalytic subunit of the oligosaccharyltransferase complex |
| NCBI Official Symbol: | STT3B |
| NCBI Official Synonym Symbols: | SIMP; CDG1X; STT3-B |
| NCBI Protein Information: | dolichyl-diphosphooligosaccharide--protein glycosyltransferase subunit STT3B |
| UniProt Protein Name: | Dolichyl-diphosphooligosaccharide--protein glycosyltransferase subunit STT3B |
| UniProt Synonym Protein Names: | Source of immunodominant MHC-associated peptides homolog |
| Protein Family: | Dolichyl-diphosphooligosaccharide--protein glycosyltransferase |
| UniProt Gene Name: | STT3B |
