|
Your query returned 1 entry. Printable version
EC | 3.2.1.209 | ||||||||||||||
Accepted name: | endoplasmic reticulum Man9GlcNAc2 1,2-α-mannosidase | ||||||||||||||
Reaction: | Man9GlcNAc2-[protein] + H2O = Man8GlcNAc2-[protein] (isomer 8A1,2,3B1,3) + D-mannopyranose | ||||||||||||||
Glossary: | Man9GlcNAc2-[protein] = {α-D-Man-(1→2)-α-D-Man-(1→2)-α-D-Man-(1→3)-[α-D-Man-(1→2)-α-D-Man-(1→3)-[α-D-Man-(1→2)-α-D-Man-(1→6)]-α-D-Man-(1→6)]-β-D-Man-(1→4)-β-D-GlcNAc-(1→4)-α-D-GlcNAc}-N-Asn-[protein] Man8GlcNAc2-[protein] (isomer 8A1,2,3B1,3) = {α-D-Man-(1→2)-α-D-Man-(1→2)-α-D-Man-(1→3)-[α-D-Man-(1→3)-[α-D-Man-(1→2)-α-D-Man-(1→6)]-α-D-Man-(1→6)]-β-D-Man-(1→4)-β-D-GlcNAc-(1→4)-α-D-GlcNAc}-N-Asn-[protein] |
||||||||||||||
Other name(s): | MAN1B1 (gene name); MNS1 (gene name); MNS3 (gene name) | ||||||||||||||
Systematic name: | Man9GlcNAc2-[protein]2-α-mannohydrolase (configuration-inverting) | ||||||||||||||
Comments: | The enzyme, located in the endoplasmic reticulum, primarily trims a single α-1,2-linked mannose residue from Man9GlcNAc2 to produce Man8GlcNAc2 isomer 8A1,2,3B1,3 (the names of the isomers listed here are based on a nomenclature system proposed by Prien et al [7]). The removal of the single mannosyl residue occurs in all eukaryotes as part of the processing of N-glycosylated proteins, and is absolutely essential for further elongation of the outer chain of properly-folded N-glycosylated proteins in yeast. In addition, the enzyme is involved in glycoprotein quality control at the ER quality control compartment (ERQC), helping to target misfolded glycoproteins for degradation. When present at very high concentrations in the ERQC, the enzyme can trim the carbohydrate chain further to Man(5-6)GlcNAc2. | ||||||||||||||
Links to other databases: | BRENDA, EXPASY, KEGG, MetaCyc | ||||||||||||||
References: |
| ||||||||||||||