Structural and functional insights into a dodecameric molecular machine - The RuvBL1/RuvBL2 complex
Structural and functional insights into a dodecameric molecular machine - The RuvBL1/RuvBL2 complex
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DOI：
10.1016/j.jsb.2011.09.001
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发表时间：
2011-12-01
影响因子：
3
通讯作者：
Carrondo, Maria Armenia
中科院分区：
文献类型：
--
作者：
Gorynia, Sabine;Bandeiras, Tiago M.;Carrondo, Maria Armenia
RuvBL1（RuvB-like 1）及其同源物 RuvBL2 是进化上高度保守的 AAA(+) ATP 酶，对许多细胞活动至关重要。它们在染色质重塑、转录调控和 DNA 损伤修复中发挥着重要作用。 RuvBL1 和 RuvBL2 在不同类型的癌症中过度表达，并与主要致癌因子相互作用，例如调节其功能的 β-catenin 和 c-Myc。我们解析了具有截短结构域 II 的人类 RuvBL 复合物的第一个三维晶体结构，并表明该复合物具有解旋酶活性。该结构揭示了由两个异六聚体环组成的十二聚体，其中交替的 RuvBL1 和 RuvBL2 单体与 ADP/ATP 结合，它们通过结构域 II 的保留部分相互作用。通过小角X射线散射分析证实了晶体结构中观察到的R1 Delta DII/R2 Delta DII复合物的十二聚四级结构。有趣的是，结构域II的截断导致RuvBL1、RuvBL2及其复合物的ATP消耗大幅增加。此外，我们提供的证据表明，人类 RuvBL 蛋白的 DNA 解旋可以被结构域 II 自动抑制，而同源细菌解旋酶 RuvB 中不存在该结构域 II。我们的数据为 RuvBL1 和 RuvBL2 的分子排列提供了新的见解，并强烈表明这些非常有趣的治疗药物靶点的体内活性受到辅因子的调节，辅因子通过结构域 II 诱导构象变化，从而将酶复合物调节到其活性状态。 (C) 2011 Elsevier Inc. 保留所有权利。
RuvBL1 (RuvB-like 1) and its homolog RuvBL2 are evolutionarily highly conserved AAA(+) ATPases essential for many cellular activities. They play an important role in chromatin remodeling, transcriptional regulation and DNA damage repair. RuvBL1 and RuvBL2 are overexpressed in different types of cancer and interact with major oncogenic factors, such as beta-catenin and c-Myc regulating their function. We solved the first three-dimensional crystal structure of the human RuvBL complex with a truncated domain II and show that this complex is competent for helicase activity. The structure reveals a dodecamer consisting of two heterohexameric rings with alternating RuvBL1 and RuvBL2 monomers bound to ADP/ATP, that interact with each other via the retained part of domain II. The dodecameric quaternary structure of the R1 Delta DII/R2 Delta DII complex observed in the crystal structure was confirmed by small-angle X-ray scattering analysis.Interestingly, truncation of domain II led to a substantial increase in ATP consumption of RuvBL1, RuvBL2 and their complex. In addition, we present evidence that DNA unwinding of the human RuvBL proteins can be auto-inhibited by domain II, which is not present in the homologous bacterial helicase RuvB. Our data give new insights into the molecular arrangement of RuvBL1 and RuvBL2 and strongly suggest that in vivo activities of these highly interesting therapeutic drug targets are regulated by cofactors inducing conformational changes via domain II in order to modulate the enzyme complex into its active state. (C) 2011 Elsevier Inc. All rights reserved.