Aliases for STT3B Gene
- STT3 Oligosaccharyltransferase Complex Catalytic Subunit B 2 3 5
- Dolichyl-Diphosphooligosaccharide--Protein Glycosyltransferase Subunit STT3B 2 3 4
- STT3-B 2 3 4
- SIMP 2 3 4
- STT3B, Catalytic Subunit Of The Oligosaccharyltransferase Complex 2 3
- Dolichyl-Diphosphooligosaccharide Protein Glycotransferase 2 3
- Source Of Immunodominant MHC-Associated Peptides Homolog 3 4
- Oligosaccharyl Transferase Subunit STT3B 3 4
- STT3, Subunit Of The Oligosaccharyltransferase Complex, Homolog B (S. Cerevisiae) 2
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]
GeneCards Summary for STT3B Gene
STT3B (STT3 Oligosaccharyltransferase Complex Catalytic Subunit B) is a Protein Coding gene. Diseases associated with STT3B include Congenital Disorder Of Glycosylation, Type Ix and Immunodeficiency 47. Among its related pathways are Protein processing in endoplasmic reticulum and N-Glycan biosynthesis. Gene Ontology (GO) annotations related to this gene include dolichyl-diphosphooligosaccharide-protein glycotransferase activity and oligosaccharyl transferase activity. An important paralog of this gene is STT3A.
UniProtKB/Swiss-Prot Summary for STT3B Gene
Catalytic subunit of the oligosaccharyl transferase (OST) complex that catalyzes the initial transfer of a defined glycan (Glc(3)Man(9)GlcNAc(2) in eukaryotes) from the lipid carrier dolichol-pyrophosphate to an asparagine residue within an Asn-X-Ser/Thr consensus motif in nascent polypeptide chains, the first step in protein N-glycosylation. 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). All subunits are required for a maximal enzyme activity. This subunit contains the active site and the acceptor peptide and donor lipid-linked oligosaccharide (LLO) binding pockets (By similarity). 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 (PubMed:19167329, PubMed:22607976).