N-terminal catalytic domain of mammalian cytosolic alpha-mannosidase Man2C1 and similar proteins; glycoside hydrolase family 38 (GH38)
The subfamily corresponds to cytosolic alpha-mannosidase Man2C1 (also known as ER-mannosidase II or neutral/cytosolic mannosidase), mainly found in various vertebrates, and similar proteins. Man2C1 plays an essential role in the catabolism of cytosolic free oligomannosides derived from dolichol intermediates and the degradation of newly synthesized glycoproteins in ER or cytosol. It can catalyze the cleavage of alpha 1,2-, alpha 1,3-, and alpha 1,6-linked mannose residues. Man2C1 is a cobalt-dependent enzyme belonging to alpha-mannosidase class II. It has a neutral pH optimum and is strongly inhitibed by furanose analogs swainsonine (SW) and 1,4-dideoxy-1,4-imino-D-mannitol (DIM), moderately by deoxymannojirimycin (DMM), but not by kifunensine (KIF). DMM and KIF, both pyranose analogs, are normally known to inhibit class I alpha-mannosidase.