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Literature summary for 2.4.99.18 extracted from
- Oligosaccharyltransferase: the central enzyme of N-linked protein glycosylation (2011), J. Inherit. Metab. Dis., 34, 869-878.
Activating Compound
| Activating Compound | Comment | Organism | Structure |
|---|---|---|---|
| additional information | DAD1 might provide structural and functional integrity for the OST complex | Saccharomyces cerevisiae |
Protein Variants
| Protein Variants | Comment | Organism |
|---|---|---|
| G374D | the missense mutation lies in the second half of the N-terminal luminal domain of ribophorin II subunit, the affected patient presents a fairly mild clinical phenotype, no clear genotype-phenotype correlation for this mutation | Homo sapiens |
General Stability
| General Stability | Organism |
|---|---|
| DAD1 might provide structural and functional integrity for the OST complex | Saccharomyces cerevisiae |
Localization
| Localization | Comment | Organism | GeneOntology No. | Textmining |
|---|---|---|---|---|
| endoplasmic reticulum membrane | - |
Homo sapiens | 5789 | - |
| endoplasmic reticulum membrane | - |
Saccharomyces cerevisiae | 5789 | - |
| endoplasmic reticulum membrane | - |
Canis lupus familiaris | 5789 | - |
Natural Substrates/ Products (Substrates)
| Natural Substrates | Organism | Comment (Nat. Sub.) | Natural Products | Comment (Nat. Pro.) | Rev. | Reac. |
|---|---|---|---|---|---|---|
| dolichyl diphosphooligosaccharide + [protein]-L-asparagine | Saccharomyces cerevisiae | transfer of a preassembled, uniform oligosaccharide (Glc3Man9GlcNAc2 in most eukaryotes) from the isoprenoid lipid carrier dolichol diphosphate to the side-chain amide group nitrogen of an asparagine residue contained in a N-X-S(T) sequon of the polypeptide substrate, where X can be any amino acid except proline, mechanism, overview | dolichyl diphosphate + [protein]-L-asparagine-N-oligosaccharide | a glycoprotein with the oligosaccharide chain attached by N-beta-D-glycosyl linkage to a protein L-asparagine | ? |  |
| dolichyl diphosphooligosaccharide + [protein]-L-asparagine | Canis lupus familiaris | transfer of a preassembled, uniform oligosaccharide (Glc3Man9GlcNAc2 in most eukaryotes) from the isoprenoid lipid carrier dolichol diphosphate to the side-chain amide group nitrogen of an asparagine residue contained in a N-X-S(T) sequon of the polypeptide substrate, where X can be any amino acid except proline, mechanism, overview | dolichyl diphosphate + [protein]-L-asparagine-N-oligosaccharide | a glycoprotein with the oligosaccharide chain attached by N-beta-D-glycosyl linkage to a protein L-asparagine | ? | |
| dolichyl diphosphooligosaccharide + [protein]-L-asparagine | Homo sapiens | transfer of a preassembled, uniform oligosaccharide (Glc3Man9GlcNAc2 in most eukaryotes) from the isoprenoid lipid carrier dolichol pyrophosphate to the side-chain amide group nitrogen of an asparagine residue contained in a N-X-S(T) sequon of the polypeptide substrate, where X can be any amino acid except proline, mechanism, modeling, overview | dolichyl diphosphate + [protein]-L-asparagine-N-oligosaccharide | a glycoprotein with the oligosaccharide chain attached by N-beta-D-glycosyl linkage to a protein L-asparagine | ? | |
| additional information | Saccharomyces cerevisiae | tight association of DAD1 with the active OST complex with specific interactions between the N-terminal domain of DAD1 and subunit OST48 | ? | - |
? | |
Organism
| Organism | UniProt | Comment | Textmining |
|---|---|---|---|
| Canis lupus familiaris | - |
- |
- |
| Homo sapiens | - |
- |
- |
| Saccharomyces cerevisiae | - |
- |
- |
Source Tissue
| Source Tissue | Comment | Organism | Textmining |
|---|---|---|---|
| HeLa cell | - |
Homo sapiens | - |
Substrates and Products (Substrate)
| Substrates | Comment Substrates | Organism | Products | Comment (Products) | Rev. | Reac. |
|---|---|---|---|---|---|---|
| dolichyl diphosphooligosaccharide + [protein]-L-asparagine | - |
Homo sapiens | dolichyl diphosphate + [protein]-L-asparagine-N-oligosaccharide | a glycoprotein with the oligosaccharide chain attached by N-beta-D-glycosyl linkage to a protein L-asparagine | ? | |
| dolichyl diphosphooligosaccharide + [protein]-L-asparagine | - |
Saccharomyces cerevisiae | dolichyl diphosphate + [protein]-L-asparagine-N-oligosaccharide | a glycoprotein with the oligosaccharide chain attached by N-beta-D-glycosyl linkage to a protein L-asparagine | ? | |
| dolichyl diphosphooligosaccharide + [protein]-L-asparagine | - |
Canis lupus familiaris | dolichyl diphosphate + [protein]-L-asparagine-N-oligosaccharide | a glycoprotein with the oligosaccharide chain attached by N-beta-D-glycosyl linkage to a protein L-asparagine | ? | |
| dolichyl diphosphooligosaccharide + [protein]-L-asparagine | transfer of a preassembled, uniform oligosaccharide (Glc3Man9GlcNAc2 in most eukaryotes) from the isoprenoid lipid carrier dolichol diphosphate to the side-chain amide group nitrogen of an asparagine residue contained in a N-X-S(T) sequon of the polypeptide substrate, where X can be any amino acid except proline, mechanism, overview | Saccharomyces cerevisiae | dolichyl diphosphate + [protein]-L-asparagine-N-oligosaccharide | a glycoprotein with the oligosaccharide chain attached by N-beta-D-glycosyl linkage to a protein L-asparagine | ? | |
| dolichyl diphosphooligosaccharide + [protein]-L-asparagine | transfer of a preassembled, uniform oligosaccharide (Glc3Man9GlcNAc2 in most eukaryotes) from the isoprenoid lipid carrier dolichol diphosphate to the side-chain amide group nitrogen of an asparagine residue contained in a N-X-S(T) sequon of the polypeptide substrate, where X can be any amino acid except proline, mechanism, overview | Canis lupus familiaris | dolichyl diphosphate + [protein]-L-asparagine-N-oligosaccharide | a glycoprotein with the oligosaccharide chain attached by N-beta-D-glycosyl linkage to a protein L-asparagine | ? | |
| dolichyl diphosphooligosaccharide + [protein]-L-asparagine | transfer of a preassembled, uniform oligosaccharide (Glc3Man9GlcNAc2 in most eukaryotes) from the isoprenoid lipid carrier dolichol pyrophosphate to the side-chain amide group nitrogen of an asparagine residue contained in a N-X-S(T) sequon of the polypeptide substrate, where X can be any amino acid except proline, mechanism, modeling, overview | Homo sapiens | dolichyl diphosphate + [protein]-L-asparagine-N-oligosaccharide | a glycoprotein with the oligosaccharide chain attached by N-beta-D-glycosyl linkage to a protein L-asparagine | ? | |
| additional information | tight association of DAD1 with the active OST complex with specific interactions between the N-terminal domain of DAD1 and subunit OST48 | Saccharomyces cerevisiae | ? | - |
? | |
| additional information | high substrate specificity of OST | Homo sapiens | ? | - |
? | |
Subunits
| Subunits | Comment | Organism |
|---|---|---|
| heptamer | heteromeric OST complex comprising seven subunits, Stt3 proteins are the catalytic subunits of eukaryotic OST complexes, structure-function relationships, ddetailed overview. In the yeast OST complex, OST4p regulates the incorporation of the two functionally equivalent, but mutually exclusive, subunits OST3p and OST6p | Canis lupus familiaris |
| heptamer | heteromeric OST complex comprising seven subunits, Stt3 proteins are the catalytic subunits of eukaryotic OST complexes, structure-function relationships, detailed overview. Canine OST isoforms harboring the different Stt3 proteins differ in catalytic activity and substrate selectivity. OST complexes with the Stt3-B isoform are more active reaching 8 to 12fold higher Vmax values for glycopeptide formation than complexes containing Stt3-A | Saccharomyces cerevisiae |
| heptamer | the heptameric human OST complex contains the subunits ribophorin I (OST1p), ribophorin II (Swp1p), OST48 (Wbp1p), OST4 (OST4), Stt3-A/Stt3-B (Stt3p), N33/Tusc3 and IAP (OST3p and OST6p), and DAD1 (OST2p), struccture-function relationships, Stt3 proteins are the catalytic subunits of eukaryotic OST complexes, detailed overview. Human OST4 contains a very short luminal segment with one transmembrane span followed by a cytoplasmic part consisting of approximately ten residues | Homo sapiens |
Synonyms
| Synonyms | Comment | Organism |
|---|---|---|
| oligosaccharyltransferase | - |
Homo sapiens |
| oligosaccharyltransferase | - |
Saccharomyces cerevisiae |
| oligosaccharyltransferase | - |
Canis lupus familiaris |
| OST | - |
Homo sapiens |
| OST | - |
Saccharomyces cerevisiae |
| OST | - |
Canis lupus familiaris |
General Information
| General Information | Comment | Organism |
|---|---|---|
| evolution | OST is a heterooligomeric membrane protein complex in animals, plants, and fungi. In bacteria, archaea, and protozoa, OST is a monomer | Homo sapiens |
| evolution | OST is a heterooligomeric membrane protein complex in animals, plants, and fungi. In bacteria, archaea, and protozoa, OST is a monomer | Saccharomyces cerevisiae |
| evolution | OST is a heterooligomeric membrane protein complex in animals, plants, and fungi. In bacteria, archaea, and protozoa, OST is a monomer | Canis lupus familiaris |
| malfunction | instability of the temperature-sensitive DAD1 mutant at restrictive temperature causes a time-dependent degradation of the other OST subunits ribophorin I, ribophorin II, and OST48, disrupting the entire OST complex. Loss of OST activity caused by DAD1 instability results in severe hypoglycosylation that might induce apoptosis. Mutations affecting the biosynthesis of the activated Glc3Man9GlcNAc2 oligosaccharide substrate or the biogenesis of OSTs generally have a systemic effect in eukaryotes and alter glycosylation of many different glycoproteins | Saccharomyces cerevisiae |
| malfunction | mutations affecting the biosynthesis of the activated Glc3Man9GlcNAc2 oligosaccharide substrate or the biogenesis of OSTs generally have a systemic effect in eukaryotes and alter glycosylation of many different glycoproteins | Canis lupus familiaris |
| malfunction | mutations affecting the biosynthesis of the activated Glc3Man9GlcNAc2 oligosaccharide substrate or the biogenesis of OSTs generally have a systemic effect in eukaryotes and alter glycosylation of many different glycoproteins. It is the substrate specificity of OST that translates defects in the biosynthesis of the oligosaccharide substrate into a generalized and multisystemic deficiency observed for the different forms of human congenital disorders of glycosylation type I. Mutations in the subunit paralogues N33/Tusc3 and IAP do not yield the pleiotropic phenotypes typical for CDG type I but specifically result in nonsyndromic mental retardation | Homo sapiens |
| metabolism | in the central reaction of the N-linked glycosylation pathway, one of the most abundant modifications of proteins in eukaryotes, oligosaccharyltransferase, a multimeric complex located at the membrane of the endoplasmic reticulum, transfers a preassembled oligosaccharide to selected asparagine residues within the consensus sequence asparagine-X-serine/threonine | Homo sapiens |
| metabolism | in the central reaction of the N-linked glycosylation pathway, one of the most abundant modifications of proteins in eukaryoties, oligosaccharyltransferase, a multimeric complex located at the membrane of the endoplasmic reticulum, transfers a preassembled oligosaccharide to selected asparagine residues within the consensus sequence asparagine-X-serine/threonine | Saccharomyces cerevisiae |
| metabolism | in the central reaction of the N-linked glycosylation pathway, one of the most abundant modifications of proteins in eukaryoties, oligosaccharyltransferase, a multimeric complex located at the membrane of the endoplasmic reticulum, transfers a preassembled oligosaccharide to selected asparagine residues within the consensus sequence asparagine-X-serine/threonine | Canis lupus familiaris |
| additional information | Canine OST isoforms harboring the different Stt3 proteins differ in catalytic activity and substrate selectivity. OST complexes with the Stt3-B isoform are more active reaching 8 to 12fold higher Vmax values for glycopeptide formation than complexes containing Stt3-A. The increased catalytic activity for Stt3-B complexes coincides with a reduced selectivity with respect to the oligosaccharide donor substrate. OST complexes with Stt3-B accept the dolichol-pyrophosphate-activated Glc3Man9GlcNAc2 and Man9GlcNAc2 substrates with roughly the same specificity, whereas OST complexes with Stt3-A are more selective, as reflected by increased Km values forMan9GlcNAc2 relative to Glc3Man9GlcNAc2. Stt3-A and Stt3-B also differ in their acceptor substrate selectivity | Saccharomyces cerevisiae |
| additional information | OST complexes containing Stt3-B are more active than OST complexes harboring Stt3-A. Stt3-A and Stt3-B also differ in their acceptor substrate selectivity | Homo sapiens |
| physiological function | In the yeast OST complex, OST4p regulates the incorporation of the two functionally equivalent, but mutually exclusive, subunits OST3p and OST6p. the catalytic subunit of the eukaryotic OST and catalyzes the transfer of a highly defined, lipid-linked oligosaccharide (LLO) donor substrate to a multitude of peptide acceptor sequences located in different substrate proteins | Canis lupus familiaris |
| physiological function | the catalytic subunit of the eukaryotic OST and catalyzes the transfer of a highly defined, lipid-linked oligosaccharide (LLO) donor substrate to a multitude of peptide acceptor sequences located in different substrate proteins | Saccharomyces cerevisiae |
| physiological function | the catalytic subunit of the eukaryotic OST and catalyzes the transfer of a highly defined, lipid-linked oligosaccharide (LLO) donor substrate to a multitude of peptide acceptor sequences located in different substrate proteins. The Stt3 subunit of OST harbors the catalytic center of the enzyme, and some components of the OST complex are involved in the recognition and utilization of glycosylation sites in specific glycoproteins. The oxidoreductase activity of subunits N33/Tusc3 and IAP is required for glycosylation of a subset of proteins essential for brain development | Homo sapiens |
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