Names & Taxonomy
- Uniprot ID:
- P46977
- Entry Name:
- STT3A_HUMAN
- Status:
- reviewed
- Protein Names:
- Dolichyl-diphosphooligosaccharide--protein glycosyltransferase subunit STT3A (Oligosaccharyl transferase subunit STT3A) (STT3-A) (EC 2.4.99.18) (B5) (Integral membrane protein 1) (Transmembrane protein TMC)
- Gene Names:
- STT3A ITM1 TMC
- Gene Names Primary:
- STT3A
- Organism:
- Homo sapiens (Human)
Structure
- Length:
- 705
- Sequence:
- MTKFGFLRLSYEKQDTLLKLLILSMAAVLSFSTRLFAVLRFESVIHEFDPYFNYRTTRFLAEEGFYKFHNWFDDRAWYPLGRIIGGTIYPGLMITSAAIYHVLHFFHITIDIRNVCVFLAPLFSSFTTIVTYHLTKELKDAGAGLLAAAMIAVVPGYISRSVAGSYDNEGIAIFCMLLTYYMWIKAVKTGSICWAAKCALAYFYMVSSWGGYVFLINLIPLHVLVLMLTGRFSHRIYVAYCTVYCLGTILSMQISFVGFQPVLSSEHMAAFGVFGLCQIHAFVDYLRSKLNPQQFEVLFRSVISLVGFVLLTVGALLMLTGKISPWTGRFYSLLDPSYAKNNIPIIASVSEHQPTTWSSYYFDLQLLVFMFPVGLYYCFSNLSDARIFIIMYGVTSMYFSAVMVRLMLVLAPVMCILSGIGVSQVLSTYMKNLDISRPDKKSKKQQDSTYPIKNEVASGMILVMAFFLITYTFHSTWVTSEAYSSPSIVLSARGGDGSRIIFDDFREAYYWLRHNTPEDAKVMSWWDYGYQITAMANRTILVDNNTWNNTHISRVGQAMASTEEKAYEIMRELDVSYVLVIFGGLTGYSSDDINKFLWMVRIGGSTDTGKHIKENDYYTPTGEFRVDREGSPVLLNCLMYKMCYYRFGQVYTEAKRPPGFDRVRNAEIGNKDFELDVLEEAYTTEHWLVRIYKVKDLDNRGLSRT
- Proteomes:
- UP000005640
Subcellular location
- Subcellular Location:
- Endoplasmic reticulum membrane; Multi-pass membrane protein.
Function
- 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). SST3A seems to be involved in complex substrate specificity. STT3A is present in the majority of OST complexes and mediates cotranslational N-glycosylation of most sites on target proteins, while STT3B-containing complexes are required for efficient cotranslational glycosylation and mediate glycosylation of sites that have been skipped by STT3A.
- Pathway:
- Protein modification; protein glycosylation.
- Catalytic Activity:
- Dolichyl diphosphooligosaccharide + -L-asparagine = dolichyl diphosphate + a glycoprotein with the oligosaccharide chain attached by N-beta-D-glycosyl linkage to a protein L-asparagine.
- Gene Ontology Go:
- endoplasmic reticulum membrane
integral component of membrane
membrane
oligosaccharyltransferase complex
dolichyl-diphosphooligosaccharide-protein glycotransferase activity
cellular protein metabolic process
co-translational protein modification
post-translational protein modification
protein N-linked glycosylation via asparagine - Gene Ontology Biological Process:
- cellular protein metabolic process
co-translational protein modification
post-translational protein modification
protein N-linked glycosylation via asparagine - Gene Ontology Molecular Function:
- dolichyl-diphosphooligosaccharide-protein glycotransferase activity
- Gene Ontology Cellular Component:
- endoplasmic reticulum membrane
integral component of membrane
membrane
oligosaccharyltransferase complex - Keywords:
- Alternative splicing
Complete proteome
Congenital disorder of glycosylation
Disease mutation
Endoplasmic reticulum
Glycoprotein
Glycosyltransferase
Membrane
Reference proteome
Transferase
Transmembrane
Transmembrane helix - Interacts With:
- O43187; Q6PDS3; Q86WV6