1HL9: Crystal Structure Of Thermotoga Maritima Alpha-Fucosidase In Complex With A Mechanism Based Inhibitor

Citation:
Abstract
Fucosylated glycoconjugates are involved in numerous biological events, and alpha-l-fucosidases, the enzymes responsible for their processing, are therefore of crucial importance. Deficiency in alpha-l-fucosidase activity is associated with fucosidosis, a lysosomal storage disorder characterized by rapid neurodegeneration, resulting in severe mental and motor deterioration. To gain insight into alpha-l-fucosidase function at the molecular level, we have determined the crystal structure of Thermotoga maritima alpha-l-fucosidase. This enzyme assembles as a hexamer and displays a two-domain fold, composed of a catalytic (beta/alpha)(8)-like domain and a C-terminal beta-sandwich domain. The structures of an enzyme-product complex and of a covalent glycosyl-enzyme intermediate, coupled with kinetic and mutagenesis studies, allowed us to identify the catalytic nucleophile, Asp(244), and the Bronsted acid/base, Glu(266). Because T. maritima alpha-l-fucosidase occupies a unique evolutionary position, being far more closely related to the mammalian enzymes than to any other prokaryotic homolog, a structural model of the human enzyme was built to document the structural consequences of the genetic mutations associated with fucosidosis.
PDB ID: 1HL9Download
MMDB ID: 26323
PDB Deposition Date: 2003/3/14
Updated in MMDB: 2012/12
Experimental Method:
x-ray diffraction
Resolution: 2.25  Å
Source Organism:
Similar Structures:
Biological Unit for 1HL9: hexameric; determined by author and by software (PQS)
Molecular Components in 1HL9
Label Count Molecule
Proteins (6 molecules)
6
Putative Alpha-l-fucosidase
Molecule annotation
Chemicals (6 molecules)
1
6
* Click molecule labels to explore molecular sequence information.

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