2OSW: Endo-glycoceramidase Ii From Rhodococcus Sp

Citation:
Abstract
endo-Glycoceramidase, a membrane-associated family 5 glycosidase, deviates from the typical polysaccharide substrate specificity of other soluble members of the family, preferentially hydrolyzing glycosidic linkages between the oligosaccharide and ceramide moieties of gangliosides. Here we report the first x-ray crystal structures of an endo-glycoceramidase from Rhodococcus sp., in the apo form, in complex with the ganglioside G(M3) (Svennerholm ganglioside nomenclature (Svennerholm, L. (1964) J. Lipid Res. 5, 145-155)), and trapped as a glycosyl-enzyme intermediate. These snapshots provide the first molecular insight into enzyme recognition and association with gangliosides, revealing the structural adaptations necessary for glycosidase-catalyzed hydrolysis and detailing a novel ganglioside binding topology. Consistent with the chemical duality of the substrate, the active site of endo-glycoceramidase is split into a wide, polar cavity to bind the polyhydroxylated oligosaccharide moiety and a narrow, hydrophobic tunnel to bind the ceramide lipid chains. The specific interactions with the ceramide polar head group manifest a surprising aglycone specificity, an observation substantiated by our kinetic analyses. Collectively, the reported structural and kinetic data provide insight toward rational redesign of the synthetic glycosynthase mutant of endo-glycoceramidase to enable facile synthesis of nonnatural, therapeutically useful gangliosides.
PDB ID: 2OSWDownload
MMDB ID: 44786
PDB Deposition Date: 2007/2/6
Updated in MMDB: 2017/10
Experimental Method:
x-ray diffraction
Resolution: 1.6  Å
Source Organism:
Similar Structures:
Biological Unit for 2OSW: monomeric; determined by author
Molecular Components in 2OSW
Label Count Molecule
Protein (1 molecule)
1
Endoglycoceramidase II
Molecule annotation
Chemicals (3 molecules)
1
2
2
1
* Click molecule labels to explore molecular sequence information.

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