3cv5
From Proteopedia
GOLGI MANNOSIDASE II D204A catalytic nucleophile mutant complex with 3alpha,6alpha-mannopentaose
Structural highlights
FunctionMAN2_DROME Catalyzes the first committed step in the biosynthesis of complex N-glycans. It controls conversion of high mannose to complex N-glycans; the final hydrolytic step in the N-glycan maturation pathway (By similarity). Evolutionary Conservation Check, as determined by ConSurfDB. You may read the explanation of the method and the full data available from ConSurf. Publication Abstract from PubMedGolgi alpha-mannosidase II (GMII) is a key glycosyl hydrolase in the N-linked glycosylation pathway. It catalyzes the removal of two different mannosyl linkages of GlcNAcMan(5)GlcNAc(2), which is the committed step in complex N-glycan synthesis. Inhibition of this enzyme has shown promise in certain cancers in both laboratory and clinical settings. Here we present the high-resolution crystal structure of a nucleophile mutant of Drosophila melanogaster GMII (dGMII) bound to its natural oligosaccharide substrate and an oligosaccharide precursor as well as the structure of the unliganded mutant. These structures allow us to identify three sugar-binding subsites within the larger active site cleft. Our results allow for the formulation of the complete catalytic process of dGMII, which involves a specific order of bond cleavage, and a major substrate rearrangement in the active site. This process is likely conserved for all GMII enzymes-but not in the structurally related lysosomal mannosidase-and will form the basis for the design of specific inhibitors against GMII. Golgi alpha-mannosidase II cleaves two sugars sequentially in the same catalytic site.,Shah N, Kuntz DA, Rose DR Proc Natl Acad Sci U S A. 2008 Jul 15;105(28):9570-5. Epub 2008 Jul 3. PMID:18599462[1] From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. See AlsoReferences
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