Explorations of linked editosome domains leading to the discovery of motifs defining conserved pockets in editosome OB-folds.
Explorations of linked editosome domains leading to the discovery of motifs defining conserved pockets in editosome OB-folds.
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DOI：
10.1016/j.jsb.2012.07.012
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发表时间：
2012-11
影响因子：
3
通讯作者：
Hol, Wim G. J.
中科院分区：
文献类型：
--
作者：
Park, Young-Jun;Hol, Wim G. J.
锥虫体构成了一组原生动物，其中包含人类、动物和植物的寄生虫。这些物种中有几种会引发重大的人类疾病，包括布氏锥虫，它是人类非洲锥虫病（也称为昏睡病）的病原体。这些生物具有许多极不寻常的特征，包括在单个线粒体中独特的U插入/缺失RNA编辑过程。一种关键的多蛋白复合物，称为~20S编辑体，或简称为编辑体，执行一系列关键的RNA修饰反应，并包含12种不同蛋白质的核心，其中6种是相互作用蛋白A1到A6。这些相互作用蛋白中的每一种都包含一个C末端的OB折叠结构，并且最小的相互作用蛋白A6已被证明能与其他4种编辑体的OB折叠结构相互作用。在此我们报告一种“连接的OB折叠”方法的结果，以了解多个OB折叠在编辑体核心中可能如何相互作用。在25个表达和共表达实验中，连接结构域的多种变体构建体产生了13种可溶的多OB折叠复合物。在一些情况下，这些复合物在大小上比从相应的未连接的OB折叠结构获得的复合物更均一。与A6连接的A3OB的晶体结构能够被阐明，并证实了这两个OB结构域之间的紧密相互作用，正如我们最近在A3OB和A6与纳米抗体的复合物中所看到的那样。在当前与A6连接的A3OB的晶体结构中，疏水侧链位于相邻OB折叠结构域的明确界定的口袋中。当分析编辑体OB折叠结构的现有晶体结构时，似乎在5种情况下，A1OB、A3OB和A6的“口袋1”被来自相邻蛋白质的疏水侧链占据。在这3种不同的OB折叠结构中，口袋1由两个保守的序列基序和一个不变的精氨酸形成。这些口袋可能通过与来自其他蛋白质的疏水侧链相互作用，在编辑体的组装或机制中发挥关键作用。
Trypanosomatids form a group of protozoa which contain parasites of human, animals and plants. Several of these species cause major human diseases, including Trypanosoma brucei which is the causative agent of human African trypanosomiasis, also called sleeping sickness. These organisms have many highly unusual features including a unique U-insertion/deletion RNA editing process in the single mitochondrion. A key multi-protein complex, called the ~20S editosome, or editosome, carries out a cascade of essential RNA-modifying reactions and contains a core of 12 different proteins of which six are the interaction proteins A1 to A6. Each of these interaction proteins comprises a C-terminal OB-fold and the smallest interaction protein A6 has been shown to interact with four other editosome OB-folds. Here we report the results of a “linked OB-fold” approach to obtain a view of how multiple OB-folds might interact in the core of the editosome. Constructs of multiple variants of linked domains in 25 expression and co-expression experiments resulted in 13 soluble multi-OB-fold complexes. In several instances, these complexes were more homogeneous in size than those obtained from corresponding unlinked OB-folds. The crystal structure of A3OB linked to A6 could be elucidated and confirmed the tight interaction between these two OB domains as seen also in our recent complex of A3OB and A6 with nanobodies. In the current crystal structure of A3OB linked to A6, hydrophobic side chains reside in well-defined pockets of neighboring OB-fold domains. When analyzing the available crystal structures of editosome OB-folds, it appears that in five instances “Pocket 1” of A1OB, A3OB and A6 is occupied by a hydrophobic side chain from a neighboring protein. In these three different OB-folds, Pocket 1 is formed by two conserved sequence motifs and an invariant arginine. These pockets might play a key role in the assembly or mechanism of the editosome by interacting with hydrophobic side chains from other proteins.
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影响因子：
5.8
作者：
Gouet, P;Courcelle, E;Métoz, F
通讯作者：
Métoz, F
DOI：
10.1107/s0907444904019158
发表时间：
2004-12-01
影响因子：
2.2
作者：
Emsley, P;Cowtan, K
通讯作者：
Cowtan, K
影响因子：
5.6
作者：
Demir, Oezlem;Amaro, Rommie E.
通讯作者：
Amaro, Rommie E.
影响因子：
64.5
作者：
Aphasizhev, R;Sbicego, S;Simpson, L
通讯作者：
Simpson, L
影响因子：
2.5
作者：
Gao, Guanghan;Rogers, Kestrel;Simpson, Larry
通讯作者：
Simpson, Larry