Crystal Structure of Thermotoga Maritima Alpha-L-Fucosidase. Insights Into the Catalytic Mechanism and the Molecular Basis for Fucosidosis.Sulzenbacher, G., Bignon, C., Nishimura, T., Tarling, C.A., Withers, S.G., Henrissat, B., Bourne, Y.
(2004) J.Biol.Chem. 279: 13119
- PubMed: 14715651
- DOI: 10.1074/jbc.M313783200
- Primary Citation of Related Structures:
- PubMed 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 fucosidos ...
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 Brønsted 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.
Architecture et Fonction des Macromolécules Biologiques, UMR 6098, CNRS, and Universités Aix-Marseille I and II, 31 Chemin J. Aiguier, F-13402 Marseille Cedex 20, France.