Charoenwattanasatien Ratana, Pengthaisong Salila, Breen Imogen, Mutoh Risa, Sansenya Sompong, Hua Yanling, Tankrathok Anupong, Wu Liang, Songsiriritthigul Chomphunuch, Tanaka Hideaki, Williams Spencer J, Davies Gideon J, Kurisu Genji, Cairns James R Ketudat
Institute for Protein Research, Osaka University , 3-2 Yamadaoka, Suita, Osaka 565-0871, Japan.
School of Biochemistry, Institute of Science, Suranaree Univerity of Technology , Nakhon Ratchasima 30000, Thailand.
ACS Chem Biol. 2016 Jul 15;11(7):1891-900. doi: 10.1021/acschembio.6b00192. Epub 2016 May 6.
Human glucosylcerebrosidase 2 (GBA2) of the CAZy family GH116 is responsible for the breakdown of glycosphingolipids on the cytoplasmic face of the endoplasmic reticulum and Golgi apparatus. Genetic defects in GBA2 result in spastic paraplegia and cerebellar ataxia, while cross-talk between GBA2 and GBA1 glucosylceramidases may affect Gaucher disease. Here, we report the first three-dimensional structure for any GH116 enzyme, Thermoanaerobacterium xylanolyticum TxGH116 β-glucosidase, alone and in complex with diverse ligands. These structures allow identification of the glucoside binding and active site residues, which are shown to be conserved with GBA2. Mutagenic analysis of TxGH116 and structural modeling of GBA2 provide a detailed structural and functional rationale for pathogenic missense mutations of GBA2.
糖基水解酶家族GH116中的人类葡糖脑苷脂酶2（GBA2）负责在内质网和高尔基体细胞质面的糖鞘脂分解。GBA2的基因缺陷会导致痉挛性截瘫和小脑共济失调，而GBA2与GBA1葡糖神经酰胺酶之间的相互作用可能会影响戈谢病。在此，我们报告了首个GH116酶（嗜热栖热放线菌TxGH116β-葡糖苷酶）单独及与多种配体结合的三维结构。这些结构有助于识别糖苷结合位点和活性位点残基，结果表明这些残基与GBA2保守。对TxGH116的诱变分析和GBA2的结构建模为GBA2的致病性错义突变提供了详细的结构和功能原理。
