Crystal Structures of Glycoside Hydrolase Family 51 α-<scp>L</scp>-Arabinofuranosidase from<i>Thermotoga maritima</i>
作者:Do-Hyun IM、Kei-ichi KIMURA、Fumitaka HAYASAKA、Tomonari TANAKA、Masato NOGUCHI、Atsushi KOBAYASHI、Shin-ichiro SHODA、Kentaro MIYAZAKI、Takayoshi WAKAGI、Shinya FUSHINOBU
DOI:10.1271/bbb.110902
日期:2012.2.23
α-l-Arabinofuranosidase from the hyperthermophilic bacterium Thermotoga maritima (Tm-AFase) is an extremely thermophilic enzyme belonging to glycoside hydrolase family 51. It can catalyze the transglycosylation of a novel glycosyl donor, 4,6-dimethoxy-1,3,5-triazin-2-yl (DMT)-β-d-xylopyranoside. In this study we determined the crystal structures of Tm-AFase in substrate-free and complex forms with arabinose and xylose at 1.8–2.3 Å resolution to determine the architecture of the substrate binding pocket. Subsite −1 of Tm-AFase is similar to that of α-l-arabinofuranosidase from Geobacillus stearothermophilus, but the substrate binding pocket of Tm-AFase is narrower and more hydrophobic. Possible substrate binding modes were investigated by automated docking analysis.
来自海洋嗜热菌(Thermotoga maritima)的α-l-阿拉伯呋喃糖苷酶(Tm-AFase)是一种嗜热性极强的酶,属于糖苷水解酶家族 51。它能催化新型糖基供体--4,6-二甲氧基-1,3,5-三嗪-2-基(DMT)-β-d-吡喃木糖苷的转糖基化反应。在这项研究中,我们以 1.8-2.3 Å 的分辨率测定了 Tm-AFase 的无底物晶体结构以及与阿拉伯糖和木糖的复合物晶体结构,以确定底物结合口袋的结构。Tm-AFase 的亚位点-1 与来自嗜热地衣芽孢杆菌的 α-l-arabinofuranosidase 的亚位点-1 相似,但 Tm-AFase 的底物结合口袋更窄、更疏水。通过自动对接分析研究了可能的底物结合模式。