2.4.99.18: dolichyl-diphosphooligosaccharide-protein glycotransferase
This is an abbreviated version!
For detailed information about dolichyl-diphosphooligosaccharide-protein glycotransferase, go to the full flat file.
Word Map on EC 2.4.99.18
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2.4.99.18
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n-glycosylation
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n-linked
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glycans
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lipid-linked
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sequons
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asparagine-linked
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jejuni
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campylobacter
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dolichol
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ribophorins
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otase
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cotranslational
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bloc
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dolichol-linked
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translocon
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glc3man9glcnac2
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heptasaccharide
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s-layer
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underglycosylation
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preassembled
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mannosyltransferases
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glycoengineering
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hypoglycosylation
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hetero-oligomeric
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single-subunit
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translocon-associated
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man9glcnac2
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lari
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drug development
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biotechnology
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medicine
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n-glycoproteins
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glycoproteomics
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pilins
- 2.4.99.18
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n-glycosylation
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n-linked
- glycans
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lipid-linked
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sequons
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asparagine-linked
- jejuni
- campylobacter
- dolichol
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ribophorins
- otase
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cotranslational
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bloc
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dolichol-linked
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translocon
- glc3man9glcnac2
- heptasaccharide
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s-layer
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underglycosylation
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preassembled
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mannosyltransferases
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glycoengineering
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hypoglycosylation
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hetero-oligomeric
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single-subunit
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translocon-associated
- man9glcnac2
- lari
- drug development
- biotechnology
- medicine
- n-glycoproteins
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glycoproteomics
- pilins
Reaction
Synonyms
AglB, AglB-L, AlgB, asparagine N-glycosyltransferase, DGL1, dolichyl-diphosphooligosaccharide--protein glycosyltransferase subunit OST2, dolichyl-diphosphooligosaccharide-protein glycosyltransferase, dolichyldiphosphooligosaccharide-protein oligosaccharyltransferase, EC 2.4.1.119, glycosyltransferase, dolichyldiphosphooligosaccharide-protein, glycosyltransferase, dolichylpyrophosphodiacetylchitobiose-protein, L.m.STT3, Lm STT3, oligomannosyltransferase, oligosaccharide transferase, oligosaccharyl transferase, oligosaccharyl transferase 16 kDa subunit, oligosaccharyl transferase subunit epsilon, oligosaccharyl transferase subunit OST2, oligosaccharyltransferase, oligosaccharyltransferase complex, oligosaccharyltransferase STT3, oligosaccharyltransferase, dolichyldiphosphoryloligosaccharide-protein, OST, OST-A, OST-B, OST-I, OST-II, OST-III, OST1, OST2, OST3, Ost3p, OST4, OST5, Ost6p, OSTC(I), OSTC(II), OSTC(III), OTase, PglB, PglB oligosaccharyltransferase, PglB1, PglL, PilO, STT3, STT3 protein, STT3-1, STT3-2, STT3-3, STT3-4, Swp1p, TbSTT3A, TbSTT3B, TbSTT3C, Wbp1p, yeast oligosaccharyl transferase
ECTree
2.4.99.18 dolichyl-diphosphooligosaccharide-protein glycotransferaseAdvanced search results
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General Information on EC 2.4.99.18 - dolichyl-diphosphooligosaccharide-protein glycotransferase
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GENERAL INFORMATION 
ORGANISM
UNIPROT
COMMENTARY 
LITERATURE
evolution
malfunction
metabolism
physiological function
additional information
evolution
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OST is a heterooligomeric membrane protein complex in animals, plants, and fungi. In bacteria, archaea, and protozoa, OST is a monomer
evolution
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OST is a heterooligomeric membrane protein complex in animals, plants, and fungi. In bacteria, archaea, and protozoa, OST is a monomer
evolution
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OST is a heterooligomeric membrane protein complex in animals, plants, and fungi. In bacteria, archaea, and protozoa, OST is a monomer
evolution
the catalytic subunit of OST is called STT3 in eukaryotes, AglB in archaea, and PglB in eubacteria. Archaeoglobus f ulgidus encodes three AglB paralogues, two of them are the shortest AglBs across all domains of life.
evolution
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the catalytic subunit of OST is called STT3 in eukaryotes, AglB in archaea, and PglB in eubacteria. Archaeoglobus f ulgidus encodes three AglB paralogues, two of them are the shortest AglBs across all domains of life.
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malfunction
congenital disorders of glycosylation (CDG) have severe effects in humans, complete loss is lethal for eukaryots
malfunction
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simultaneous TbSTT3A and TbSTT3B knockdown prevents parasite growth in the bloodstream
malfunction
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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
malfunction
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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
malfunction
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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
malfunction
P46977; P0C6T2; P61165; P61803; P04843; P04844; P39656; Q9NRP0, Q8TCJ2; P0C6T2; P61165; P61803; P04843; P04844; P39656; Q9NRP0
defects in N-linked glycosylation results in a class of inherited diseases known as congenital disorders of glycosylation
metabolism
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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
metabolism
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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
metabolism
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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
physiological function
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free monomeric enzyme with broad specificity for nonglucosylated lipid-linked mannose-oligosaccharides typical for protists, incorporated in yeast enzyme complex it also transfers the common eukaryotic Glc3Man9GlcNAc2-PP-Dol donor
physiological function
N-linked glycosylation of nascent polypeptides in the lumen of the endoplasmic reticulum
physiological function
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O-glycosylation of type IV pilins in bacteria
physiological function
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subunits Ost3p and Ost6p are necessary for efficient glycosylation of distinct defined glycosylation sites
physiological function
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TbSTT3A and TbSTT3B N-glycosylation together is essential for infectivity in mice
physiological function
asparagine-linked glycosylation is a common and vital co- and post-translocational modification of diverse secretory and membrane proteins in eukaryotes that is catalyzed by the multiprotein complex oligosaccharyltransferase. Isozymes Ost3p or Ost6p possess different protein substrate specificities at the level of individual glycosylation sites, model of Ost3/6p function in which they transiently bind stretches of nascent polypeptide substrate to inhibit protein folding, thereby increasing glycosylation efficiency at nearby asparagine residues
physiological function
asparagine-linked glycosylation is a common and vital co- and post-translocational modification of diverse secretory and membrane proteins in eukaryotes that is catalyzed by the multiprotein complex oligosaccharyltransferase. Ispzymes Ost3p or Ost6p possess different protein substrate specificities at the level of individual glycosylation sites. Ost6p, which has a peptide-binding groove with a strongly hydrophobic base lined by neutral and basic residues, binds peptides enriched in hydrophobic and acidic amino acids. Model of Ost3/6p function in which they transiently bind stretches of nascent polypeptide substrate to inhibit protein folding, thereby increasing glycosylation efficiency at nearby asparagine residues
physiological function
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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
physiological function
oligosaccharyltransferase transfers glycan to asparagine in the N-glycosylation sequon, the lysine and isoleucine residues in the DK/MI motif participate in the Ser/Thr recognition in the sequon
physiological function
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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
physiological function
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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
physiological function
asparagine-linked glycosylation (N-linked glycosylation) is an essential and highly conserved post-translational protein modification. This modification is essential for specific molecular recognition, protein folding, sorting in the endoplasmic reticulum, cell-cell communication, and stability
physiological function
P46977; P0C6T2; P61165; P61803; P04843; P04844; P39656; Q9NRP0, Q8TCJ2; P0C6T2; P61165; P61803; P04843; P04844; P39656; Q9NRP0
asparagine-linked glycosylation (N-linked glycosylation) is an essential and highly conserved post-translational protein modification. This modification is essential for specific molecular recognition, protein folding, sorting in the endoplasmic reticulum, cell-cell communication, and stability. In humans and other mammals, the oligosaccharyltransferase (OST) complex has diverged into two distinct isoforms known as OST-A and OST-B that perform distinctly different roles in N-linked glycosylation of proteins. OST-A is connected directly to the translocation channel called Sec61 in the ER membrane and scans the newly synthesized unfolded polypeptide chain emerging from the ribosome for glycosylation sites. Therefore, OST-A is responsible for the majority of N-linked glycosylation in mammals. OST-B seems to act in a proofreading role to catch glycosylation sites that OST-A misses for partially folded proteins or proteins that contain disulfide bonds
physiological function
P46977; P0C6T2; P61165; P61803; P04843; P04844; P39656; Q9NRP0, Q8TCJ2; P0C6T2; P61165; P61803; P04843; P04844; P39656; Q9NRP0
oligosaccharyltransferase (OST) catalyzes the transfer of a high-mannose glycan onto secretory proteins in the endoplasmic reticulum. Mammals express two distinct oligosaccharyltransferase complexes that act in a cotranslational (OST-A) or posttranslocational (OST-B) manner. The distinct functions of the two human complexes are based on structural differences of their catalytic subunits STT3A and STT3B, which result in interactions with distinct subunits and different affinities for acceptor peptides
physiological function
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oligosaccharyltransferase transfers glycan to asparagine in the N-glycosylation sequon, the lysine and isoleucine residues in the DK/MI motif participate in the Ser/Thr recognition in the sequon
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physiological function
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asparagine-linked glycosylation (N-linked glycosylation) is an essential and highly conserved post-translational protein modification. This modification is essential for specific molecular recognition, protein folding, sorting in the endoplasmic reticulum, cell-cell communication, and stability
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additional information
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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
additional information
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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
additional information
Ost3p structure-function relationship, overview
additional information
Ost3p structure-function relationship, overview
additional information
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Ost3p structure-function relationship, overview
additional information
Ost6p structure-function relationship, overview
additional information
Ost6p structure-function relationship, overview
additional information
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Ost6p structure-function relationship, overview
