N-terminal catalytic domain of Golgi alpha-mannosidase IIx, and similar proteins; glycoside hydrolase family 38 (GH38)
This subfamily is represented by human alpha-mannosidase 2x (MX, also known as mannosyl-oligosaccharide 1,3- 1,6-alpha mannosidase, EC 3.2.1.114, Man2A2). MX is enzymatically and functionally very similar to GMII (found in another subfamily), and as an isoenzyme of GMII. It is thought to also function in the N-glycosylation pathway. MX specifically hydrolyzes the same oligosaccharide substrate as does MII. It specifically removes two mannosyl residues from GlcNAc(Man)5(GlcNAc)2 to yield GlcNAc(Man)3(GlcNAc)2(GlcNAc, N-acetylglucosmine).