title: Structure of Golgi alpha-mannosidase II: a target for inhibition of growth and metastasis of cancer cells.
abstract: Golgi alpha-mannosidase II, a key enzyme in N-glycan processing, is a target in the development of anti- cancer therapies. The crystal structure of Drosophila Golgi alpha-mannosidase II in the absence and presence of the anti-cancer agent swainsonine and the inhibitor deoxymannojirimycin reveals a novel protein fold with an active site zinc intricately involved both in the substrate specificity of the enzyme and directly in the catalytic mechanism. Identification of a putative GlcNAc binding pocket in the vicinity of the active site cavity provides a model for the binding of the GlcNAcMan(5)GlcNAc(2) substrate and the consecutive hydrolysis of the alpha1,6- and alpha1,3-linked mannose residues. The enzyme-inhibitor interactions observed provide insight into the catalytic mechanism, opening the door to the design of novel inhibitors of alpha-mannosidase II.
authors.affiliation: Ontario Cancer Institute and Department of Medical Biophysics, University of Toronto, 610 University Avenue, Toronto, Ontario, Canada.
authors.forename: J M
authors.initials: JM
authors.lastname: van den Elsen
authors.forename: D A
authors.initials: DA
authors.lastname: Kuntz
authors.forename: D R
authors.initials: DR
authors.lastname: Rose
mesh_terms: D017485:1-Deoxynojirimycin / Q000494:pharmacology; D000595:Amino Acid Sequence; D000818:Animals; D000972:Antineoplastic Agents, Phytogenic / Q000494:pharmacology; D001665:Binding Sites; D002384:Catalysis; D002455:Cell Division; D002460:Cell Line; D018360:Crystallography, X-Ray; D004331:Drosophila melanogaster / Q000737:chemistry; D004791:Enzyme Inhibitors / Q000494:pharmacology; D015870:Gene Expression; D008361:Mannosidases / Q000037:antagonists & inhibitors / Q000737:chemistry* / Q000235:genetics; D008958:Models, Molecular; D008969:Molecular Sequence Data; D009362:Neoplasm Metastasis; D017433:Protein Structure, Secondary; D013379:Substrate Specificity; D017026:Swainsonine / Q000494:pharmacology; D014407:Tumor Cells, Cultured
chemical_list: D000972:Antineoplastic Agents, Phytogenic; D004791:Enzyme Inhibitors; D017485:1-Deoxynojirimycin; D008361:Mannosidases; C038829:mannosyl-oligosaccharide 1,3 - 1,6-alpha-mannosidase; D017026:Swainsonine