Revisiting the NMR solution structure of the Cel48S type-I dockerin module from Clostridium thermocellum reveals a cohesin-primed conformation
Revisiting the NMR solution structure of the Cel48S type-I dockerin module from Clostridium thermocellum reveals a cohesin-primed conformation
复制标题
重新审视热纤梭菌 Cel48S I 型 dockerin 模块的 NMR 溶液结构，揭示了粘连蛋白引发的构象
DOI：
10.1016/j.jsb.2014.09.006
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发表时间：
2014-11-01
影响因子：
3
通讯作者：
Feng, Yingang
中科院分区：
文献类型：
--
作者：
Chen, Chao;Cui, Zhenling;Feng, Yingang
多纤维素酶亚基的Dockerin模块通过与支架蛋白亚基的粘附蛋白模块牢固结合而在多纤维素酶的组装中发挥重要作用。先前报道的来自热纤梭菌Ce 148 S的I型锚定蛋白模块的NMR衍生的溶液结构，其利用二维同源H-1-H-1 NOESY和三维N-15编辑的NOESY距离限制，显示出与随后的锚定蛋白模块及其同源粘附蛋白模块复合结构的构象差异，这就提出了一个问题，即所观察到的差异的来源是否是由粘着蛋白诱导的结构重排引起的。在这里，我们根据N-15和C-13编辑的NOESY推导的距离约束确定了Ce 148 S I型对接的解结构。该结构采用了类似于与其粘附蛋白伴侣复合的锚定蛋白模块的X射线晶体结构的折叠。在本结构中还鉴定了Ce 148 S I型锚定蛋白模块中Leu-65和Pro-66之间的独特顺式肽键。我们对Ce 148 S I型锚定蛋白模块的结构分析表明，它没有发生明显的粘附素诱导的结构改变，而是假设固有的钙依赖性粘附素引发的构象。(C)2014 Elsevier Inc. All rights reserved.
Dockerin modules of the cellulosomal enzyme subunits play an important role in the assembly of the cellulosome by binding tenaciously to cohesin modules of the scaffoldin subunit. A previously reported NMR-derived solution structure of the type-I dockerin module from Ce148S of Clostridium thermocellum, which utilized two-dimensional homonuclear H-1-H-1 NOESY and three-dimensional N-15-edited NOESY distance restraints, displayed substantial conformational differences from subsequent structures of dockerin modules in complex with their cognate cohesin modules, raising the question whether the source of the observed differences resulted from cohesin-induced structural rearrangements. Here, we determined the solution structure of the Ce148S type-I dockerin based on N-15- and C-13-edited NOESY-derived distance restraints. The structure adopted a fold similar to X-ray crystal structures of dockerin modules in complex with their cohesin partners. A unique cis-peptide bond between Leu-65 and Pro-66 in the Ce148S type-I dockerin module was also identified in the present structure. Our structural analysis of the Ce148S type-I dockerin module indicates that it does not undergo appreciable cohesin-induced structural alterations but rather assumes an inherent calcium-dependent cohesin-primed conformation. (C) 2014 Elsevier Inc. All rights reserved.