Structural and mutational analyses of the interaction between the barley α-amylase/subtilisin inhibitor and the subtilisin Savinase reveal a novel mode of inhibition
Structural and mutational analyses of the interaction between the barley α-amylase/subtilisin inhibitor and the subtilisin Savinase reveal a novel mode of inhibition
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DOI：
10.1016/j.jmb.2008.05.034
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发表时间：
2008-07-18
影响因子：
5.6
通讯作者：
Skjot, Michael
中科院分区：
文献类型：
--
作者：
Micheelsen, Pernille Ollendorff;Vevodova, Jitka;Skjot, Michael
枯草杆菌是一类微生物丝氨酸蛋白酶。迄今为止，在蛋白质数据库中有来自三个家族的蛋白抑制剂与枯草杆菌素复合物的三维结构。它们都通过一个覆盖六个相互作用残基的暴露环与枯草杆菌素相互作用。在这里，我们展示了lentus枯草杆菌素保存酶与大麦α -淀粉酶/枯草杆菌素抑制剂（BASI）复合物的晶体结构。这是首次报道谷物Kunitz-P家族抑制剂与枯草菌素复合物的结构。结构分析表明，BASI以一种新的方式抑制Savinase，因为相互作用环比先前报道的环短。突变分析表明，Thr88对抑制至关重要，因为它通过与BASI主链的分子内相互作用来稳定相互作用环。(C) 2008 Elsevier Ltd版权所有。
Subtilisins represent a large class of microbial serine proteases. To date, there are three-dimensional structures of proteinaceous inhibitors from three families in complex with subtilisins in the Protein Data Bank. All interact with subtilisin via an exposed loop covering six interacting residues. Here we present the crystal structure of the complex between the Bacillus lentus subtilisin Savinase and the barley alpha-amylase/subtilisin inhibitor (BASI). This is the first reported structure of a cereal Kunitz-P family inhibitor in complex with a subtilisin. Structural analysis revealed that BASI inhibits Savinase in a novel way, as the interacting loop is shorter than loops previously reported. Mutational analysis showed that Thr88 is crucial for the inhibition, as it stabilises the interacting loop through intramolecular interactions with the BASI backbone. (C) 2008 Elsevier Ltd. All rights reserved.