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ENZYME

ENZYME entry: EC 3.2.1.113

PURL: https://purl.expasy.org/enzyme/EC/3.2.1.113
Accepted Name
mannosyl-oligosaccharide 1,2-alpha-mannosidase
Alternative Name(s)
Man9-mannosidase
ManI
mannosidase 1A
mannosidase 1B
Reaction catalysed
  • N(4)-(alpha-D-Man-(1->2)-alpha-D-Man-(1->2)-alpha-D-Man-(1->3)-[alpha-D-Man-(1->2)-alpha-D-Man-(1->3)-[alpha-D-Man-(1->2)-alpha-D-Man-(1->6)]-alpha-D-Man-(1->6)]-beta-D-Man-(1->4)-beta-D-GlcNAc-(1->4)-beta-D-GlcNAc)-L-asparaginyl-[protein] (N-glucan mannose isomer 9A1,2,3B1,2,3) + 4 H2O = N(4)-(alpha-D-Man-(1->3)-[alpha-D-Man-(1->3)-[alpha-D-Man-(1->6)]-alpha-D-Man-(1->6)]-beta-D-Man-(1->4)-beta-D-GlcNAc-(1->4)-beta-D-GlcNAc)-L-asparaginyl-[protein] (N-glucan mannose isomer 5A1,2) + 4 beta-D-mannose
  • N(4)-(alpha-D-Man-(1->2)-alpha-D-Man-(1->2)-alpha-D-Man-(1->3)-[alpha-D-Man-(1->3)-[alpha-D-Man-(1->2)-alpha-D-Man-(1->6)]-alpha-D-Man-(1->6)]-beta-D-Man-(1->4)-beta-D-GlcNAc-(1->4)-beta-D-GlcNAc)-L-asparaginyl-[protein] (N-glucan mannose isomer 8A1,2,3B1,3) + 3 H2O = N(4)-(alpha-D-Man-(1->3)-[alpha-D-Man-(1->3)-[alpha-D-Man-(1->6)]-alpha-D-Man-(1->6)]-beta-D-Man-(1->4)-beta-D-GlcNAc-(1->4)-beta-D-GlcNAc)-L-asparaginyl-[protein] (N-glucan mannose isomer 5A1,2) + 3 beta-D-mannose
Comment(s)
  • This family of mammalian enzymes, located in the Golgi system, participates in the maturation process of N-glycans that leads to formation of hybrid and complex structures.
  • The enzymes catalyze the hydrolysis of the four (1->2)-linked alpha- D-mannose residues from the Man9GlcNAc2 oligosaccharide attached to target proteins.
  • Alternatively, the enzymes act on the Man8GlcNAc2 isomer formed by EC 3.2.1.209.
  • The enzymes are type II membrane proteins, require Ca(2+), and use an inverting mechanism.
  • While all three human enzymes can catalyze the reactions listed here, some of the enzymes can additionally catalyze hydrolysis in an alternative order, generating additional isomeric intermediates, although the final product is the same.
  • The names of the isomers listed here are based on a nomenclature system proposed by Prien et al.
Cross-references
Rhea expert-curated reactions3.2.1.113
ExplorEnz3.2.1.113
IUBMB Enzyme Nomenclature3.2.1.113
UniProtKB/Swiss-Prot
Q9BZQ6, EDEM3_HUMANQ2HXL6, EDEM3_MOUSEQ6GQB9, EDEM3_XENLA
P53624, MA1A1_DROMEP33908, MA1A1_HUMANP45700, MA1A1_MOUSE
O02773, MA1A1_PIGP45701, MA1A1_RABITO18498, MA1A1_SPOFR
O60476, MA1A2_HUMANP39098, MA1A2_MOUSEQ9UKM7, MA1B1_HUMAN
A2AJ15, MA1B1_MOUSEB2GUY0, MA1B1_RATQ9NR34, MA1C1_HUMAN
Q18788, MAN12_CAEELP31723, MAN12_PENCID4AV26, MNS1B_ARTBC
A1CP08, MNS1B_ASPCLA1D1W1, MNS1B_ASPF1B0XMT4, MNS1B_ASPFC
B8N417, MNS1B_ASPFNQ4WRZ5, MNS1B_ASPFUA2QAS2, MNS1B_ASPNC
Q2ULB2, MNS1B_ASPORQ12563, MNS1B_ASPPHQ0D076, MNS1B_ASPTN
E9CXX8, MNS1B_COCPSQ5BF93, MNS1B_EMENIQ9C512, MNS1_ARATH
Q8J0Q0, MNS1_CANAXQ9P7C3, MNS1_SCHPOP32906, MNS1_YEAST
Q8H116, MNS2_ARATHQ93Y37, MNS3_ARATH
BRENDA3.2.1.113
MetaCyc3.2.1.113
KEGG Ligand Database for Enzyme Nomenclature3.2.1.113
MEDLINEFind literature relating to 3.2.1.113

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