ENZYME

ENZYME entry: EC 2.4.1.259

Accepted Name

Dol-P-Man:Man(6)GlcNAc(2)-PP-Dol alpha-1,2-mannosyltransferase.

Reaction catalysed

Dolichyl beta-D-mannosyl phosphate + D-Man-alpha-(1->2)-D-Man-alpha-(1->2)-D-Man-alpha-(1->3)-(D-Man-alpha-(1->3)-D-Man-alpha-(1->6))-D-Man-beta-(1->4)-D-GlcNAc-beta-(1->4)-D-GlcNAc-diphosphodolichol <=> D-Man-alpha-(1->2)-D-Man-alpha-(1->2)-D-Man-alpha-(1->3)-(D-Man-alpha-(1->2)-D-Man-alpha-(1->3)-D-Man-alpha-(1->6))-D-Man-beta-(1->4)-D-GlcNAc-beta-(1->4)-D-GlcNAc-diphosphodolichol + dolichyl phosphate

Comment(s)

The formation of N-glycosidic linkages of glycoproteins involves the ordered assembly of the common Glc(3)Man(9)GlcNAc(2) 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 Man(5)GlcNAc(2)-PP-Dol to Man(9)Glc-NAc(2)-PP-Dol on the lumenal side use dolichyl beta-D-mannosyl phosphate.
ALG9 mannosyltransferase catalyzes the addition of two different alpha-1,2-mannose residues - the addition of alpha-1,2-mannose to Man(6)GlcNAc(2)-PP-Dol (EC 2.4.1.259) and the addition of alpha-1,2- mannose to Man(8)GlcNAc(2)-PP-Dol (EC 2.4.1.261).
Formerly EC 2.4.1.130.

Cross-references

BRENDA

2.4.1.259

EC2PDB

2.4.1.259

ExplorEnz

2.4.1.259

PRIAM enzyme-specific profiles

2.4.1.259

KEGG Ligand Database for Enzyme Nomenclature

2.4.1.259

IUBMB Enzyme Nomenclature