ID 3.2.1.113 DE Mannosyl-oligosaccharide 1,2-alpha-mannosidase. AN Man9-mannosidase. AN ManI. AN Mannosidase 1A. AN Mannosidase 1B. CA (1) Man(9)GlcNAc(2)-[protein] + 4 H(2)O = Man(5)GlcNAc(2)-[protein] + CA 4 beta-D-mannopyranose. CA (2) Man(8)GlcNAc(2)-[protein] (isomer 8A(1,2,3)B(1,3)) + 3 H(2)O = CA Man(5)GlcNAc(2)-[protein] + 3 beta-D-mannopyranose. CC -!- This family of mammalian enzymes, located in the Golgi system, CC participates in the maturation process of N-glycans that leads to CC formation of hybrid and complex structures. CC -!- The enzymes catalyze the hydrolysis of the four (1->2)-linked alpha- CC D-mannose residues from the Man(9)GlcNAc(2) oligosaccharide attached CC to target proteins. CC -!- Alternatively, the enzymes act on the Man(8)GlcNAc(2) isomer formed CC by EC 3.2.1.209. CC -!- The enzymes are type II membrane proteins, require Ca(2+), and use an CC inverting mechanism. CC -!- While all three human enzymes can catalyze the reactions listed here, CC some of the enzymes can additionally catalyze hydrolysis in an CC alternative order, generating additional isomeric intermediates, CC although the final product is the same. CC -!- The names of the isomers listed here are based on a nomenclature CC system proposed by Prien et al. DR Q9BZQ6, EDEM3_HUMAN; Q2HXL6, EDEM3_MOUSE; Q6GQB9, EDEM3_XENLA; DR P53624, MA1A1_DROME; P33908, MA1A1_HUMAN; P45700, MA1A1_MOUSE; DR O02773, MA1A1_PIG ; P45701, MA1A1_RABIT; O18498, MA1A1_SPOFR; DR O60476, MA1A2_HUMAN; P39098, MA1A2_MOUSE; Q9UKM7, MA1B1_HUMAN; DR A2AJ15, MA1B1_MOUSE; B2GUY0, MA1B1_RAT ; Q9NR34, MA1C1_HUMAN; DR Q18788, MAN12_CAEEL; P31723, MAN12_PENCI; D4AV26, MNS1B_ARTBC; DR A1CP08, MNS1B_ASPCL; B0XMT4, MNS1B_ASPFC; B8N417, MNS1B_ASPFN; DR Q4WRZ5, MNS1B_ASPFU; A2QAS2, MNS1B_ASPNC; Q2ULB2, MNS1B_ASPOR; DR Q12563, MNS1B_ASPPH; Q0D076, MNS1B_ASPTN; E9CXX8, MNS1B_COCPS; DR Q5BF93, MNS1B_EMENI; A1D1W1, MNS1B_NEOFI; Q9C512, MNS1_ARATH ; DR Q8J0Q0, MNS1_CANAX ; Q9P7C3, MNS1_SCHPO ; P32906, MNS1_YEAST ; DR Q8H116, MNS2_ARATH ; Q93Y37, MNS3_ARATH ; //