ID   3.2.1.209
DE   endoplasmic reticulum Man9GlcNAc2 1,2-alpha-mannosidase.
CA   H2O + N(4)-(alpha-D-Man-(1->2)-alpha-D-Man-(1->2)-alpha-D-Man-(1->3)-
CA   [alpha-D-Man-(1->2)-alpha-D-Man-(1->3)-[alpha-D-Man-(1->2)-alpha-D-Man-
CA   (1->6)]-alpha-D-Man-(1->6)]-beta-D-Man-(1->4)-beta-D-GlcNAc-(1->4)-beta-
CA   D-GlcNAc)-L-asparaginyl-[protein] (N-glucan mannose isomer 9A1,2,3B1,2,3)
CA   = beta-D-mannose + N(4)-(alpha-D-Man-(1->2)-alpha-D-Man-(1->2)-alpha-D-
CA   Man-(1->3)-[alpha-D-Man-(1->3)-[alpha-D-Man-(1->2)-alpha-D-Man-(1->6)]-
CA   alpha-D-Man-(1->6)]-beta-D-Man-(1->4)-beta-D-GlcNAc-(1->4)-beta-D-
CA   GlcNAc)-L-asparaginyl-[protein] (N-glucan mannose isomer 8A1,2,3B1,3).
CC   -!- The enzyme, located in the endoplasmic reticulum, primarily trims a
CC       single alpha-1,2-linked mannose residue from Man9GlcNAc2 to produce
CC       Man8GlcNAc2 isomer 8A1,2,3B1,3 (the names of the isomers listed here
CC       are based on a nomenclature system proposed by Prien et al
CC       (pmid:19181540)).
CC   -!- The removal of the single mannosyl residue occurs in all eukaryotes
CC       as part of the processing of N-glycosylated proteins, and is
CC       absolutely essential for further elongation of the outer chain of
CC       properly-folded N-glycosylated proteins in yeast.
CC   -!- In addition, the enzyme is involved in glycoprotein quality control
CC       at the ER quality control compartment (ERQC), helping to target
CC       misfolded glycoproteins for degradation.
CC   -!- When present at very high concentrations in the ERQC, the enzyme can
CC       trim the carbohydrate chain further to Man(5-6)GlcNAc2.
DR   Q9C512, MNS1_ARATH ;  Q93Y37, MNS3_ARATH ;
//