|Superclasses:||Reactions Classified By Conversion Type → Simple Reactions → Chemical Reactions|
|Reactions Classified By Substrate → Small-Molecule Reactions|
EC Number: 22.214.171.1248
Enzymes and Genes:
|Saccharomyces cerevisiae:||dolichyl-P-Man:Man5GlcNAc2-PP-dolichol α-1,3-mannosyltransferase: ALG3|
Supersedes EC number: 126.96.36.199
Reaction Locations: rough endoplasmic reticulum lumen
The direction shown, i.e. which substrates are on the left and right sides, is in accordance with the Enzyme Commission system.
Most BioCyc compounds have been protonated to a reference pH value of 7.3. Please see the PGDB Concepts Guide for more information.
Mass balance status: Balanced.
Enzyme Commission Primary Name: dolichyl-P-Man:Man5GlcNAc2-PP-dolichol α-1,3-mannosyltransferase
Enzyme Commission Synonyms: Man5GlcNAc2-PP-Dol mannosyltransferase, ALG3, dolichyl-P-Man:Man(5)GlcNAc(2)-PP-dolichyl mannosyltransferase, Not56-like protein, Alg3 α-1,3-mannosyl transferase, Dol-P-Man:Man5GlcNAc2-PP-Dol α-1,3-mannosyltransferase
Standard Gibbs Free Energy (ΔrG'° in kcal/mol): 7.52124 [Latendresse13]
Enzyme Commission Summary:
The formation of N-glycosidic linkages of glycoproteins involves the ordered assembly of the common Glc3Man9GlcNAc2 core-oligosaccharide on the lipid carrier dolichyl diphosphate. Early mannosylation steps occur on the cytoplasmic side of the endoplasmic reticulum with GDP-Man as donor, the final reactions from a (mannosyl)5-(N-acetylglucosaminyl)2-diphosphodolichol to a (mannosyl)9-(N-acetylglucosaminyl)2-diphosphodolichol on the lumenal side use dolichyl β-D-mannosyl phosphate. The first step of this assembly pathway on the luminal side of the endoplasmic reticulum is catalysed by ALG3.
Cipollo00: Cipollo JF, Trimble RB (2000). "The accumulation of Man(6)GlcNAc(2)-PP-dolichol in the Saccharomyces cerevisiae Deltaalg9 mutant reveals a regulatory role for the Alg3p alpha1,3-Man middle-arm addition in downstream oligosaccharide-lipid and glycoprotein glycan processing." J Biol Chem 275(6);4267-77. PMID: 10660594
Sharma01: Sharma CB, Knauer R, Lehle L (2001). "Biosynthesis of lipid-linked oligosaccharides in yeast: the ALG3 gene encodes the Dol-P-Man:Man5GlcNAc2-PP-Dol mannosyltransferase." Biol Chem 382(2);321-8. PMID: 11308030
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