title: Crystal structure of the covalent intermediate of human cytosolic beta-glucosidase.
abstract: Human cytosolic beta-glucosidase, also known as klotho-related protein (KLrP, GBA3), is an enzyme that hydrolyzes various beta-D-glucosides, including glucosylceramide. We recently reported the crystal structure of KLrP in complex with glucose [Y. Hayashi, N. Okino, Y. Kakuta, T. Shikanai, M. Tani, H. Narimatsu, M. Ito, Klotho-related protein is a novel cytosolic neutral beta-glycosylceramidase, J. Biol. Chem. 282 (2007) 30889-30900]. Here, we report the crystal structure of a covalent intermediate of the KLrP mutant E165Q, in which glucose was covalently bound to a nucleophile, Glu(373). The structure confirms the double displacement mechanism of the retaining beta-glucosidase. In addition, the structure suggests that a water molecule could be involved in the stabilization of transition states through a sugar, 2-hydroxyl.
authors.affiliation: Laboratory of Structural Biology, Graduate School of Systems Life Sciences, Kyushu University, Fukuoka 812-8581, Japan.
authors.forename: Junji
authors.initials: J
authors.lastname: Noguchi
authors.forename: Yasuhiro
authors.initials: Y
authors.lastname: Hayashi
authors.forename: Yuichi
authors.initials: Y
authors.lastname: Baba
authors.forename: Nozomu
authors.initials: N
authors.lastname: Okino
authors.forename: Makoto
authors.initials: M
authors.lastname: Kimura
authors.forename: Makoto
authors.initials: M
authors.lastname: Ito
authors.forename: Yoshimitsu
authors.initials: Y
authors.lastname: Kakuta
mesh_terms: D019943:Amino Acid Substitution; D018360:Crystallography, X-Ray; D005947:Glucose / Q000737:chemistry; D005960:Glucosides / Q000737:chemistry; D006801:Humans; D009154:Mutation; D011487:Protein Conformation; D001617:beta-Glucosidase / Q000737:chemistry* / Q000235:genetics
chemical_list: D005960:Glucosides; C025193:4-nitrophenyl beta-D-glucoside; C424266:GBA3 protein, human; D001617:beta-Glucosidase; D005947:Glucose