KEGG   PATHWAY: ec00510
Entry
ec00510                     Pathway                                

Name
N-Glycan biosynthesis
Description
N-glycans or asparagine-linked glycans are major constituents of glycoproteins in eukaryotes. N-glycans are covalently attached to asparagine with the consensus sequence of Asn-X-Ser/Thr by an N-glycosidic bond, GlcNAc b1- Asn. Biosynthesis of N-glycans begins on the cytoplasmic face of the ER membrane with the transferase reaction of UDP-GlcNAc and the lipid-like precursor P-Dol (dolichol phosphate) to generate GlcNAc a1- PP-Dol. After sequential addition of monosaccharides by ALG glycosyltransferases [MD:M00055], the N-glycan precursor is attached by the OST (oligosaccharyltransferase) complex to the polypeptide chain that is being synthesized and translocated through the ER membrane. The protein-bound N-glycan precursor is subsequently trimmed, extended, and modified in the ER and Golgi by a complex series of reactions catalyzed by membrane-bound glycosidases and glycosyltransferases. N-glycans thus synthesized are classified into three types: high-mannose type, complex type, and hybrid type. Defects in N-glycan biosynthesis lead to a variety of human diseases known as congenital disorders of glycosylation [DS:H00118 H00119].
Class
Metabolism; Glycan biosynthesis and metabolism
Pathway map
ec00510  N-Glycan biosynthesis
ec00510

Module
M00055  N-glycan precursor biosynthesis [PATH:ec00510]
M00072  N-glycosylation by oligosaccharyltransferase [PATH:ec00510]
M00073  N-glycan precursor trimming [PATH:ec00510]
M00074  N-glycan biosynthesis, high-mannose type [PATH:ec00510]
M00075  N-glycan biosynthesis, complex type [PATH:ec00510]
Other DBs
GO: 0006487
Enzyme
1.3.1.94   
2.4.1.101   
2.4.1.117   
2.4.1.131   
2.4.1.132   
2.4.1.141   
2.4.1.142   
2.4.1.143   
2.4.1.144   
2.4.1.145   
2.4.1.155   
2.4.1.201   
2.4.1.256   
2.4.1.257   
2.4.1.258   
2.4.1.259   
2.4.1.260   
2.4.1.261   
2.4.1.265   
2.4.1.267   
2.4.1.38   
2.4.1.68   
2.4.1.83   
2.4.99.1   
2.4.99.18   
2.7.1.108   
2.7.8.15   
3.1.3.51   
3.1.4.48   
3.2.1.106   
3.2.1.113   
3.2.1.114   
3.2.1.207   
3.2.1.209   
3.6.1.43   
Compound
C00096  GDP-mannose
C00110  Dolichyl phosphate
C00381  Dolichol
C00621  Dolichyl diphosphate
C01246  Dolichyl beta-D-glucosyl phosphate
C03021  Protein asparagine
C03862  Dolichyl phosphate D-mannose
C06081  Polyprenol
G00001  N-Acetyl-D-glucosaminyldiphosphodolichol
G00002  N,N'-Chitobiosyldiphosphodolichol
G00003   
G00004   
G00005   
G00006   
G00007   
G00008   
G00009   
G00010   
G00011   
G00012   
G00013   
G00014   
G00015   
G00016   
G00017   
G00018  DS 3
G00019   
G00020   
G00021   
G00022   
G00171   
G10526   
G10595   
G10596   
G10597   
G10598   
G10599   
G10694   
Reference
PMID:9111134
  Authors
Schutzbach JS.
  Title
The role of the lipid matrix in the biosynthesis of dolichyl-linked oligosaccharides.
  Journal
Glycoconj J 14:175-82 (1997)
DOI:10.1023/A:1018533620002
Reference
  Authors
Oriol R, Martinez-Duncker I, Chantret I, Mollicone R, Codogno P.
  Title
Common origin and evolution of glycosyltransferases using Dol-P-monosaccharides as donor substrate.
  Journal
Mol Biol Evol 19:1451-63 (2002)
DOI:10.1093/oxfordjournals.molbev.a004208
Reference
  Authors
Thiel C, Schwarz M, Peng J, Grzmil M, Hasilik M, Braulke T, Kohlschutter A, von Figura K, Lehle L, Korner C.
  Title
A new type of congenital disorders of glycosylation (CDG-Ii) provides new insights into the early steps of dolichol-linked oligosaccharide biosynthesis.
  Journal
J Biol Chem 278:22498-505 (2003)
DOI:10.1074/jbc.M302850200
Reference
  Authors
Cipollo JF, Trimble RB, Chi JH, Yan Q, Dean N.
  Title
The yeast ALG11 gene specifies addition of the terminal alpha 1,2-Man to the Man5GlcNAc2-PP-dolichol N-glycosylation intermediate formed on the cytosolic side of the endoplasmic reticulum.
  Journal
J Biol Chem 276:21828-40 (2001)
DOI:10.1074/jbc.M010896200
Reference
  Authors
Frank CG, Aebi M.
  Title
ALG9 mannosyltransferase is involved in two different steps of lipid-linked oligosaccharide biosynthesis.
  Journal
Glycobiology 15:1156-63 (2005)
DOI:10.1093/glycob/cwj002
Reference
  Authors
O'Reilly MK, Zhang G, Imperiali B.
  Title
In vitro evidence for the dual function of Alg2 and Alg11: essential mannosyltransferases in N-linked glycoprotein biosynthesis.
  Journal
Biochemistry 45:9593-603 (2006)
DOI:10.1021/bi060878o
Related
pathway
ec00051  Fructose and mannose metabolism
ec00511  Other glycan degradation
ec00513  Various types of N-glycan biosynthesis
ec00515  Mannose type O-glycan biosynthesis
ec00520  Amino sugar and nucleotide sugar metabolism
ec00533  Glycosaminoglycan biosynthesis - keratan sulfate
ec00563  Glycosylphosphatidylinositol (GPI)-anchor biosynthesis
ec00900  Terpenoid backbone biosynthesis

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